Science
[Atmospheric River] [AU's] [Aquifers] [Amino Acids] [Asteroids] [Atmosphere] [Calderas] [Canyons] [Cern] [Comets] [Continents] [CT Scanning]
[DNA] [Dimensions] [Deserts] [Doppler Effect]
[Earths Magnetic Field] [EMPs] [Our Earth] [Epicenter] [Faults] [Flooding] [Galactic Journies] [Galaxies] [Genomes] [Geologic Terms]
[Geologic Time Scale]
[Global Warming] [Gobi Desert] [Gravity] [Hail] [Hurricanes] [Double Helix] [Lahar] [Landslides] [Lasers] [Lightning] [Lithium Batteries]
[MASS] [Milky Way] [Mountains] [Nervous System] [Ocean Levels] [Ozone layer] [Observatories/Planetariums] [Oceans] [Perpetual Motion]
[Phenomena] [plate tectonics] [Proteins] [Propulsion] [Pyroclastic Flows] [RNA] [Radioactivity] [Radiological
Terms] [Reactors]
[Rivers] [Rogue Waves] [ [Seas & Lakes] [Sonoluminescence] [Sun & Water] [Tephra] [Tornadoes] [Trivia] [Tsunamis] [Seismic Waves] [Our Sun] [Solar System]
[Ultrasound] [Universe] [Volcanoes] [Volt] [Weather/Storms] [Wind] [X-Ray]
Water (H2o) expands its volume by 9% upon freezing.
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At present the composition of our
atmosphere is 79% nitrogen, 20% oxygen, and 1% other gases. The Air
pressure at sea level, the air pressure is about 14.7 pounds per square inch.
As you climb in altitude, the air pressure decreases. At an altitude of
10,000 feet, the air pressure is 10 pound per square inch (and there is less
oxygen to breathe). Conversely, when you travel down into the earth,
the pressure increases, as well as the heat.. The
Troposphere
The
troposphere is the lowest region in the Earth's atmosphere. On the Earth, it goes
from ocean (ground) level up to about 11 miles high. The weather and clouds
occur in the troposphere. In the troposphere, the temperature generally
decreases as altitude increases. is where all weather takes place; it is the
region of rising and falling packets of air. The air pressure at the top of
the troposphere is only 10% of that at sea level (0.1 atmospheres). There is
a thin buffer zone between the troposphere and the next layer called the tropopause. The
Stratosphere and Ozone Layer
Above the troposphere is the stratosphere which extends
between 11 and 31 miles above the earth's surface, and here air flow is
mostly horizontal. The thin *ozone layer in the upper stratosphere has a high
concentration of ozone, a particularly reactive form of oxygen. This layer is
primarily responsible for absorbing the ultraviolet radiation from the Sun.
The formation of this layer is a delicate matter, since only when oxygen is
produced in the atmosphere can an ozone layer form, and prevent an intense
flux of ultraviolet radiation from reaching the surface, where it is quite a
hazard to mankind, and animals alike. There is less ozone over the equator than over other
parts of the world. The average thickness is about 300 DU (Dobson Units),
which equals a three millimeter (or 0.12") thick layer cloud of
compressed ozone. Obviously, the ozone layer is really thin! The
concentration of the ozone in the ozone layer is very small, it is vitally
important to life because it absorbs biologically harmful ultraviolet (UV)
radiation emitted from the Sun. At present there is considerable concern that
man made flourocarbon compounds may be depleting the ozone (There was no
ozone 650 millions year ago) layer, with dire future consequences for
life on the Earth. Interestingly, Ozone found in the lowest levels of the
atmosphere can have harmful effects on humans. People with asthma or other
breathing problems are especially prone to its effects. The
Mesosphere
The
mesosphere is characterized by temperatures that quickly decrease as height
increases. The mesosphere extends from between 31 and 50 miles above the
earth's surface. Ionosphere
The
ionosphere (or thermosphere),
starts at about 43-50 miles high and continues for hundreds of miles (about
400 miles). where many atoms are ionized (have gained or lost electrons so
they have a net electrical charge). The ionosphere is very thin, but it is
where aurora take place, and is also responsible for absorbing the most
energetic photons from the Sun, and for reflecting radio waves, thereby
making long-distance radio communication possible. The structure of the
ionosphere is strongly influenced by the charged particle wind from the Sun
(solar wind), which is in turn governed by the level of Solar activity. One
measure of the structure of the ionosphere is the free electron density,
which is an indicator of the degree of ionization. |
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The term AU is the Astronomical unit of measurement referred to for the solar system. The distance from Earth to our Sun (93,000,000 miles) is one AU, the end of the Milky Way Galaxy being about fifty thousand AU's. A light year is 10,000,000,000,000 kilometers, an enormous distance. |
CANYONS
OF THE WORLD
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Mid-Level Clouds -Typically appear
between 6,500 to 20,000 feet (2,000 to 6,000 meters). Because of their lower
altitudes, they are composed primarily of water droplets, however, they can
also be composed of ice crystals when temperatures are cold enough. Low-Level Clouds -Mostly composed of
water droplets since their bases generally lie below 6,500 feet (2,000
meters). However, when temperatures are cold enough, these clouds may also
contain ice particles and snow.
Clouds with Vertical
Development -The cumulus cloud is
generated most commonly through either thermal convection or frontal lifting;
these clouds can grow to heights in excess of 39,000 feet (12,000 meters),
releasing incredible amounts of energy through the condensation of water
vapor within the cloud itself. Other Cloud Types
Contrails (also known as a condensation trail, is a cirrus-like
trail of condensed water vapor often resembling the tail of a kite. Contrails
are produced at high altitudes where extremely cold temperatures freeze water
droplets in a matter of seconds before they can evaporate. Often exhaust
fumes from a jet engine. If the surrounding air is cold enough, a state of
saturation is attained and ice crystals develop, producing a contrail.), Billow
clouds ( Billow clouds are created from instability associated with air
flows having marked vertical shear and weak thermal stratification), mammatus
(Mammatus are pouch-like cloud structures and a rare example of clouds in
sinking air, usually seen after the worst of a thunderstorm has passed), orographic
(When air is confronted by a mountain, it is lifted up and over the
mountain, cooling as it rises. If the air cools to its saturation point, the
water vapor condenses and a cloud forms), and pileus cloud ( is
a smooth cloud found attached to either a mountain top or growing cumulus
tower). The lowest
part of the Clouds are visible accumulations of water droplets or solid ice
crystals that float in the Earth's troposphere Earth's atmosphere),
moving with the wind. From space, clouds are visible as a white veil
surrounding the planet. Clouds form when water
vapor (water that has evaporated from the surface of the Earth) condenses
(turns into liquid water or solid ice) onto microscopic dust particles (or
other tiny particles) floating in the air. This condensation (cloud
formation) happens when warm and cold air meet, when warm air rises up the
side of a mountain and cools as it rises, and when warm air flows over a
colder area, like a cool body of water. This occurs because cool air can hold
less water vapor than warm air, and excess water condenses into either liquid
or ice. Water vapor and particles
in the air such as dust or sea spray. If the air is saturated with water, the
water vapor can condense into droplets or be deposited as ice crystals around
the particles. A collection of billions of these tiny droplets or ice
crystals forms a cloud. A mass of air can become
saturated with water when it is uplifted and cooled. Air is uplifted by a
number of different processes, including orographic ascent, convection, and
convergence. Orographic ascent takes place when the shape of the landscape
forces air upward; convection occurs when air at ground level is heated by
Earth's surface, becomes less dense, and then rises up through the cooler,
denser air above it; and convergence happens when two air masses meet,
forcing one of them upward. While most clouds are produced by uplift, some
clouds are formed when water vapor is added to the air, for example, due to
exhaust from an airplane. Clouds continuously shift
and change shape because of air movement. They dissipate as the water
droplets evaporate or move apart from each other. Winds also carry clouds across
the sky. Because different levels of the atmosphere have different winds, it
is possible to see clouds that are at different levels moving at different
speeds. If you watch clouds over a period
of time, you will likely see them forming, moving, and changing shape. These
clouds can float because they are warmer that their surrounding environment. Clouds do
not move by themselves. They are carried away by the winds that prevail at
the cloud level. The speed and direction of the winds change from layer to
layer in the atmosphere un to great heights. Sometimes a jet stream will be
blowing over our head with a speed more than a hurricane and we may not be
aware of it.
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Comets
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Inventors
of the First Computer: (Atanasoff-Berry Computer"ABC") |
Medical: CT imaging uses special
x-ray equipment to produce multiple images or pictures of the inside of the
body and a computer to join them together in cross-sectional views of the
area being studied. The images can then be examined on a computer monitor or
printed. CT scans of internal
organs, bone, soft tissue and blood vessels provide greater clarity than
conventional x-ray exams. Using specialized equipment
and expertise to create and interpret CT scans of the body, radiologists can
more easily diagnose problems such as cancers, cardiovascular disease,
infectious disease, trauma and musculoskeletal disorders. Some
common uses for CT imaging is:
Physicians
uses :
How to protect
yourself: Before you ever subject
yourself to a possible dangerous and unnecessary CT scan, consult your
doctor. Recognize that scans often produce false positives, signaling
problems where none exists. If your physician suggests you need a test
involving radiation, ask about alternatives such as echocardiography (using
high-frequency sound) or magnetic resonance imaging (MRI, using strong
magnetic fields). Neither subjects you to radiation. But neither is advanced
enough to rival the power of X-rays to give your doctors a clear view inside
your small vessels. Fluoroscopies in particular are a major source of
radiation today, because the beam stays on during the entire procedure, such
as threading a catheter or endoscope. The total dose can easily be reduced,
by using the fluoroscope only periodically, not continually. This certainly
makes good sense for doctors and their patients; patient safety is vastly
increased by reducing the amount of radiation the patients gets. RADIATION
YOU WILL RECEIVE FROM CARDIAC TESTS The annual "background
radiation" dose from cosmic rays and radioactive elements in the earth
is effectively about the same (about 10 mSv) dose as what you get from one
trip to a catheterization lab for invasive angiography. Catheterization lab
tests use X-rays of a portion of the heart to reveal blockages in small
arteries. CT (computed tomography)
angiography is non-invasive but exposes you to as much as twice the radiation
you receive from invasive angiography. Computers create CT scan images from
X-ray data. Industrial
Use: nondestructive
inspection (NDI),
is testing that does not destroy the test object. NDE is vital for
constructing and maintaining all types of components and structures. To
detect different defects such as cracking and corrosion, there are different
methods of testing available, such as X-ray (where cracks show up on the
film) and ultrasound (where cracks show up as an echo blip on the screen).
This article is aimed mainly at industrial NDT, but many of the methods
described here can be used to test the human body. In fact methods from the
medical field have often been adapted for industrial use, as was the case
with Phased array ultrasonics and Computed radiography. While destructive testing
usually provides a more reliable assessment of the state of the test object,
destruction of the test object usually makes this type of test more costly to
the test object's owner than nondestructive testing. Destructive testing is
also inappropriate in many circumstances, such as forensic
investigation. That there is a tradeoff between the cost of the test and its
reliability favors a strategy in which most test objects are inspected
nondestructively; destructive testing is performed on a sampling of test
objects that is drawn randomly for the purpose of characterizing the testing
reliability of the nondestructive test. Industrial Needs: It is very difficult to
weld or mold a solid object that has the risk of breaking in service, so
testing at manufacture and during use is often essential. During the process
of casting a metal object, for example, the metal may shrink as it cools, and
crack or introduce voids inside the structure. Even the best welders (and
welding machines) do not make 100% perfect welds. Some typical weld defects
that need to be found and repaired are lack of fusion of the weld to the
metal and porous bubbles inside the weld, both of which could cause a
structure to break or a pipeline to rupture. During their service lives,
many industrial components need regular nondestructive tests to detect damage
that may be difficult or expensive to find by everyday methods. For example:
Over the past centuries,
swordsmiths, blacksmiths, and bell-makers would listen to the ring of the
objects they were creating to get an indication of the soundness of the
material. The wheel-tapper would test the wheels of locomotives for the
presence of cracks, often caused by fatigue — a function that is now carried
out by instrumentation and referred to as the acoustic
impact technique. |
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Deoxyribonucleic acid or DNA: DNA is the hereditary
material in humans and almost all other organisms. Nearly every cell in a
person’s body has the same DNA. Most DNA is located in the cell nucleus
(where it is called nuclear DNA), but a small amount of DNA can also be found
in the mitochondria (where it is called mitochondrial DNA or mtDNA). The information in DNA is
stored as a code made up of four chemical bases: adenine , cytosine, guanine , and thymine
Human DNA consists of about
3 billion bases, and more than 99 percent of those bases are the same in all
people. The order, or sequence, of these bases determines the information
available for building and maintaining an organism, similar to the way in
which letters of the alphabet appear in a certain order to form words and
sentences. The high
molecular weight nucleic acid, DNA, is found chiefly in the nuclei of complex
cells, known as eucaryotic cells, or in the nucleoid regions of procaryotic
cells, such as bacteria. It is often associated with proteins that help to
pack it in a usable fashion.
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Named after Austrian physicist Christian Doppler
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(Three) (Four) |
QT. Geology is named after Gaea, the daughter of Chaos. |
Did you know that there is no evidence in fossil sediments of Homo Sapiens beyond the last Ice Age? |
Earth's magnetic field |
Earth's magnetic field occasionally reverses its polarity Research see's evidence of magnetic polarity reversals by examining the geologic record. When lavas or sediments solidify, they often preserve a signature of the ambient magnetic field at the time of deposition. Incredible as it may seem, the magnetic field occasionally flips over! The geomagnetic poles are currently roughly coincident with the geographic poles, but occasionally the magnetic poles wander far away from the geographic poles and undergo an "excursion" from their preferred state. Earth's dynamo has no preference for a particular polarity, so, after an excursional period, the magnetic field, upon returning to its usual state of rough alignment with the Earth’s rotational axis, could just as easily have one polarity as another. These reversals are random with no apparent periodicity to their occurrence. They can happen as often as every 10 thousand years or so and as infrequently as every 50 million years or more. The last reversal was about 780,000 years ago. Reversals are not instantaneous; they happen over a period of hundreds to thousands of years, though recent research indicates that at least one reversal could have taken place over a period of one year. |
GALACTIC JOURNIES |
Our Sun & it’s Solar system, travels around the Milky way every 230 million years.
The Milky Way is about 1,000,000,000,000,000,000 km (about 100,000 light years or about 30 kpc-(Kiloparsec) across a unit of measurement used in astronomy outside of our solar system, our Sun does not lie near the center of our Galaxy. It lies about 8 kpc from the center on what is known as the Orion Arm of the Milky Way.
The big question is if Earths mankind galactic inter-terrestrial traveler survive an incredible space journey? Someday-Absolutely! There are many types of life forms out there (likely millions and millions). With 100-200 billion (recent studies even suggest two trillion) galaxies in the ‘observable’ universe, so one can only imagine how many stars are within those galaxies. Ponder that and the trillions of planets traveling in their own solar systems around them (our earth travels around the Sun with seven siblings),
The odds say that they more than likely those of terrestrial patronage will look quite different from earthly humans, perhaps even just that of a simple single or multicellular celled organism. For certain the life (upright signage sight, hearing, smell, etc. human life) form as we know it on the planet earth will not be the same on a different planet, especially that of other Galaxies. All it would take is a small difference in the amount of gravity plus or minus or that of minerals and oxygen content to alter the physical appearance of that planet’s inhabitants, not to mention the atmosphere that we breath and specific moisture content provided on the planet earth. As an example, the adult human earthly body consist of 60% water. The amount of water content can create a difference in physical appearance due to muscular and bone structure, and then there is the light, which would affect vision, skin color and tissue texture. There is even a remote chance that they could even resemble some of the characters in Star Wars, who knows? More than likely, intelligent life forms would resemble us in some ways, or vise-versa, maybe? Of note, consider that our Solar system has been visited numerous times, maybe tens of thousands of times. Most likely, our Earth provides us earthly humans, the perfect everything, albeit, our unfortunate contributions to CO2, which at present is contrary to Earths ability to provide for a continued healthy atmosphere, which of course; must be delt with. In all likeliness, the galactic visitor would perish on Planet earth, contrary to the Star Wars planetary strange inhabitants who meet up in planets beyond.
The fact is, Planetary Science has limited knowledge of the Universe at large but Astro-science (Astronomy and Cosmology) is gaining on it. We do not know much about the real potential killer out there, this being that of radiation. There are many limitations with regard to dealing with it, but one of the present best solutions is that of a magnetic shield. This requires a lot of power, (but of course, a small reactor could provide this) but in order to reach the planetary destination and then return, this is an absolute must. Lead/aluminum is used at present for the International Space Station “ISS”, but this is in permanent orbit, and not a traveling space vehicle designed specifically for deep space travel.
We are aware of distance to our neighbors and galaxies
due to red shift, which is very helpful, but at present; a lot of speculation.
We do not really have the tools to obtain detailed information with regard to
moisture/water content and food potential source in the planets in our galaxy,
specific to oxygen, minerals, etc., except that of those in our sun’s own
group, although science is certainly learning more and more. Of note, even our nearby
planet neighbor Mars receives only about one-third the amount of sunlight as
Earth does, so light is a game changer. Fortunately, Mars does have an
abundance of frozen water below its surface. Even its gravity is only 38
percent the strength of Earth’s, its atmosphere is thin and largely made up of
carbon dioxide, and the surface is backed in radiation, among other challenges.
Could it be? That Mars was once a thriving planet similar to Earth? Due to the conditions on the planet Mars, in perhaps
four or five generations, Man would look different from the Earthlings initial
visitors. Even if it was inhabited, a life form would be
different from earthlings. I would apotheosize that we have had many visitors
to our Solar system, and without a doubt, the visitors upon landing on Terra firma would likely perish due to our water
environment of planet Earth, they would most likely perish due to drowning, Earth’s
gravity or that of the many bacteria on our planet. Quite likely, the very
reason they do not attempt to colonize Earth-they can’t. Then there is the distance to our closest star ‘in the Milky way Galaxy‘ of which we are a tiny- minuscule member, note: to travel across the milky way it would take 100,000 light years. It would require traveling at the speed of light for about 4.24 light years to distant Proxima Centauri. Do consider that you would be traveling at a sustained speed of 60,000 km/hr for 76,000 continuous years. A note of interest here, today’s science lacks the propulsion & support necessary to get there, to ‘physically explore ‘beyond, even that of Mars (a six month-one-way journey), let alone beyond and in a reasonable time period and then return them safely to earth. The necessary propulsion, maybe? would be utilizing present day conventional planetary travel fuel to a certain point, and then futuristic methods, such as Ion, or perhaps pulse that would kick in at a certain point, when beyond earth’s present gravity limitations.
Although we still would most likely utilize slingshot
kicks, utilizing planets near-by gravity while traveling near them. No matter
which, we are a very long way from the necessary propulsion system(s) necessary
to go much further than Mars; with man on-board. Someday, we will perhaps find
a method to defy gravity, thus releasing man from earth’s
gravitational grip, and then develop the ability to travel at extreme
speed and distance and achieve perhaps “Bent space, which is not a potential
reality for a very-very long time” (the authors Father felt certain that the
above will become reality in the next few centuries ‘He stated this at the end
of the 20th Century and W. Frederick Petler was a man of Genus’.
This is defying today’s known science, and the space voyagers never come back. Another scenario would be no one will be there, as perhaps their civilization has been gone for millions or billions of years (do consider that we are potentially dealing with Civilization that went extinct a very long time ago, and we just received a signal). The next question would be the targeted planet as to its stability and sustainability. The proposed target would have to mirror the highly stable conditions our earth provides; just the right type of sunlight and water for life to evolve on the planet. Of course, gravity, as we know it is critical.
Keeping our space travelers alive for perhaps thousands of years is a huge (truly an understatement) undertaking. Then there is the radiation. Our travelers would be vulnerable to it from the time they reach the earth’s ionosphere which is about 30 miles above earth, providing a protecting/shielding for our space travelers would in itself be a massive undertaking since we presently lack the ability to provide protection, not to mention the necessary weight restraints, although this hurdle could certainly be overcome.
As to the topic of suspended animation during the
spacefaring journey? This is likely 50 plus years out since this task is a
truly herculean endeavor. The planet earth is but a pebble in the Milky Way
galaxy, and in the big picture of the Universe (which is REALLY Big; to quote
my Father in layman terms for my benefit), much less than a grain of sand in
size. It is most likely that there is indeed life in the Universe, but we are
at the present rate, hundreds of years, if not thousands of years before we can
even travel to the nearest galaxy, if ever? Most likely, the starting point of this intergalactic voyage would begin at the present International Space Station, and likely the spacecraft would be almost as large as the ISS, as gravity restraints would be much less, than taking off from our planet Earth.
As to present mankind initiating a spacefaring galactic journey this is most likely a resounding NO! At this time juncture, and as to “Beam me up Scotty” not possible, this is re-arranging matter, no can do!
How big is the Universe One ask? Well, it is really big, and we are a very long way from even having the tools to see how far it actually goes; most likely – to infinity, so there is no finding the edge. But then again?
In closing, a thought to consider with regard to the little white E.T. ghostly visitors with large eyes that periodically come up pertaining to alien visitors. If, in fact, they are for real, answers to appearance are due to their coming from a constant temperature environment that is likely warm and very steady, as they have no body hair, their skin pale due to less sun exposure, their eyes are large because perhaps they live in a darker environment? Also, their appearance suggest that they do not have adequate vitamin D, thus causing a frailer look, not that this is meant to mean they are weak, just that they look frail or that perhaps they live underground or in enclosed terrestrial campus’s.
And then there is the problem of space debris, at the speed our voyagers are traveling, how do you avoid it. This is not like having the immediate ability to quickly maneuver, etc. as the spacefarers are traveling at tens of thousands of miles per hour.’
For now, and for the foreseeable next century, the best bet would be to voyage to Mars and begin colonization, if it could sustain colonization? And one more very critical subject is the very possible threat to the subject planet’s inhabitants due to our introducing viruses and bacterium’s, we brought with us, or our space faring members infecting the host planets.
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The Great Gobi Desert |
The
Gobi is 500,000 square miles (1,300,000 square km) and defined as lying
between the Altai Mountains and Hangayn Mountains to the north; the
western edge of the Da Hinggan Range to the east; the Yin, Qilian,
eastern Altun, and Bei mountains to the south; and the eastern Tien
Shan to the west. The
Gobi region is in the Himalayan rain shadow, and this desert is one of
the world’s most prolific dust-producing regions on Earth. Interesting
though, much of the Gobi is not sandy desert but bare rock, and it is
possible to drive over this surface by car for long distances in any
direction. These
dust storms are not due to mankind’s activities, as they have been
occurring for tens of thousands of years. They are the product of waves
of dust particles, due to the ‘sparsely vegetated grasslands of the
Gobi’, which frequently give rise to dust storms, especially in
springtime. These
storms generated in the Gobi Desert of northern China and southern
Mongolia are massive volumes of airborne dust particles, occasionally
they circumvent the earth. They are swirling low pressure storm systems
that kick up dust and sand, often looking pink in color from high
altitude. The
beginnings of the Gobi Desert are in Mongolia, blowing the fine
airborne particles into China. This has happened thousands of times
over eons of times, but in 1970’s-1990’s, it appears that the end
results were the beginnings of a wave of allergies to mankind never
before experienced before, in-volume. It would appear that the winds
in-route, picked up minute particles of many types of molds and
combined allergens carnage, and then dispersing them worldwide, thus,
it would appear that that was a new addition to mankind’s allergy
problems? As to Global change, it certainly is also a contributor to the increase of allergy problems. |
"Terra" |
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Liquefaction occurs when the strength and
stiffness of a soil is reduced by earthquake shaking or other rapid loading.
*Liquefaction and related phenomena have been responsible for tremendous
amounts of damage in historical earthquakes around the world. Liquefaction
occurs in saturated soils, that is, soils in which the space between
individual particles is completely filled with water. This water exerts a
pressure on the soil particles that influences how tightly the particles
themselves are pressed together. Prior to an earthquake, the water pressure
is relatively low. However, earthquake shaking can cause the water pressure
to increase to the point where the soil particles can readily move with
respect to each other, which happens when loosely packed, water-logged
sediments lose their strength in response to strong shaking, causes major
damage during earthquakes. Typical
effects of liquefaction include: Loss of
bearing strength
–the ground can liquefy and lose its ability to support structures. Lateral
spreading - the
ground can slide down very gentle slopes or toward stream banks riding on a
buried liquefied layer. Sand
boils -
sand-laden water can be ejected from a buried liquefied layer and erupt at
the surface to form sand volcanoes; the surrounding ground often fractures
and settles. Quicksand is not a unique
type of soil; it is usually just sand or another type of grainy soil.
Quicksand is nothing more than a soupy mixture of sand and water. It can
occur anywhere under the right conditions. Quicksand is created when
water saturates an area of loose sand and the ordinary sand is agitated.
When the water trapped in the batch of sand can't escape, it creates liquefied soil
that can no longer support weight. There are two ways in which sand can
become agitated enough to create quicksand: The vibration plus the
water barrier reduces the friction between the sand particles and causes the
sand to behave like a liquid. To understand quicksand, you have to understand
the process of liquefaction. When soil liquefies, as
with quicksand, it loses strength and behaves like a viscous liquid rather
than a solid. Liquefaction can cause buildings to sink significantly during
earthquakes. While quicksand can occur
in almost any location where water is present, there are certain locations
where it's more prevalent. Places where quicksand is most likely to occur
include: On beaches, Lakes shorelines, Marshes, Riverbanks and near springs. If you step
into quicksand, you will not be sucked down. However, your movements will cause
you to dig yourself deeper into it. When you do make contact with quicksand,
the more you struggle in it, the faster you sink. If you relax, your body
will float in it because your body is less dense. Further, quicksand is
typically inches deep and occasionally a few feet ( but not always). Quicksand has a density of
about 125 pounds per cubic foot, which means you can float more easily on
quicksand than on water. The key is to not panic. Most people who drown in
quicksand are usually those who panic and begin flailing their arms and legs.
It may be possible to drown
in quicksand if you were to fall in over your head and couldn't get your head
back above the surface, although it's rare for quicksand to be that deep.
Most likely, if you fall in, you will float to the surface. However, the sand-to-water ratio
of quicksand can vary, causing some quicksand to be less buoyant. When you
try pulling your leg out of quicksand or mud for that matter, you are working
against a vacuum left behind by the movement, The best thing to do is to
make slow
movements and bring yourself to the surface, then just lie on
your back, paddle slowly with your arms stretched out wide, and
if possible heading for the edge.
The hazard from landslides
can be reduced by avoiding construction on steep slopes and existing
landslides, or by stabilizing the slopes. Stability increases when ground
water is prevented from rising in the landslide mass by;covering the
landslide with an impermeable membrane, directing surface water away from the
landslide, draining ground water away from the landslide, and minimizing
surface irrigation. Slope stability is also increased when a retaining
structure and/or the weight of a soil/rock berm are placed at the toe of the
landslide or when mass is removed from the top of the slope. Landslide
Warnings:
*The New
Madrid Seismic Zone, also known as the "Reelfoot Rift" or "the
New Madrid Fault Line", is a major seismic zone in the Southern and
Midwestern United States. As a result of the quakes,
large areas sank into the earth, new lakes were formed (notably Reelfoot
Lake, Tennessee), and the Mississippi River changed its course, creating
numerous geographic exclaves, including
Kentucky Bend, along the state boundaries which are defined by the river. |
ELECTRO MAGNETIC PULSE |
EMPs are rapid, invisible bursts of electromagnetic energy. They occur in nature, most frequently during lightning strikes, and can disrupt or destroy nearby electronics.
However, nuclear EMPs —According to
US government reports, if a detonation is large enough and high enough — it can
cover an entire continent and cripple modern electronics on a massive scale, ,
this being the power grid, phone and internet lines, and other infrastructure
that uses metal may also be prone to the effects. Electromagnetic radiation is a type of energy that is all around us and
takes many forms, such as radio waves, microwaves, X-rays and
gamma-rays. Sunlight is also a form of electromagnetic energy, but
visible light is only a small portion of the electromagnetic spectrum,
which contains a broad range of wavelengths.
"The energy from the EMP is received in such a very short time,
however, that it produces a strong electric current which could damage equipment.
"An equal amount of energy When EMP passes through metal objects like a
phone, computer, or radio, they can "catch" this incredibly powerful
pulse. This can generate a rogue current of electricity that moves through a
modern device's tiny circuits and can disrupt and possibly destroy them. Power
transmission or telecommunications equipment, meanwhile, can overload from the
excess current, spark, and fail for miles around. The intensity of a nuclear detonation's EMP is about 30,000 to 50,000 volts
per meter — thousands of times greater than the one your microwave bleeds off. Fortunately, not all nuclear blasts are created equal when it comes to EMP, as
typical radio receotuib would not likely be as harmful, due to hundreds of
variables that determine whether or not an EMP affects electronics, to include;
"the size and orientation of your
device, the structure of the building you are in, plug-in or battery, if it is
behind a surge protector," and so on.
"There is a good chance that there will be plenty of functioning radios even within a few miles of the event and that radio transmission towers outside of the impacted area will still be able to send information on the safest strategy to keep you and your family safe. Because many radios have simpler, less sensitive circuitry than a phone, they're likely to be a first line of information after a ground blast.
|
El Niño, La Niña
and ENSO |
The terms
ENSO and ENSO cycle are used to describe the full range of variability
observed in the Southern Oscillation Index, including both El Niño and La
Niña events. The Southern Oscillation
Index is the difference in surface pressure between Tahiti, French Polynesia
and Darwin, Australia is a measure of the strength of the trade winds, which
have a component of flow from regions of high to low pressure. High SOI
(large pressure difference) is associated with stronger than normal trade
winds and La Niña conditions, and low SOI (smaller pressure difference) is
associated with weaker than normal trade winds and El Niño conditions. El Niño denotes a warm
southward flowing ocean current that occurs every year around late December
off the west coast of Peru and Ecuador. The term was later restricted to
unusually strong warmings that disrupted local fish and bird populations
every few years. However, as a result of the frequent association of South
American coastal temperature anomalies with interannual basin scale
equatorial warm events, El Niño has also become synonymous with larger scale,
climatically significant, warm events. There is not, however, unanimity in
the use of the term El Niño. La Niña, is defined as colder than normal
sea-surface temperatures in the central and eastern tropical Pacific ocean
that impact global weather patterns. La Niña conditions recur every few years
and can persist for as long as two years. La Niña is preceded by a buildup of
cooler-than-normal subsurface waters in the tropical Pacific. Eastward-moving
atmospheric and oceanic waves help bring the cold water to the surface
through a complex series of events still being studied. In time, the easterly
trade winds strengthen, cold upwelling off Peru and Ecuador intensifies,
sea-surface temperatures along the equator can fall as much as 7 degrees F
below normal. La Niña
conditions typically last approximately 9-12 months, and occasionally
episodes may continue for a few years. |
Galaxies are large systems of stars and interstellar matter, typically containing several million to some trillion stars. Some with masses between several million and several trillion times that of our Sun, typically separated by millions of light years in distance. The galaxies represent a variety: Spiral, lenticular, elliptical and irregular. Besides simple stars, they typically contain various types of star clusters and nebulae. Galaxies & Star Ponders What
if it is not there anymore? What we do see in the Universe are galaxies
and stars that are tens of thousands light years away? Taking thousands
of years (at the speed of light) for their light to reach us. It
would not be a stretch in pondering that many in fact are no longer
there, having burned out or absorbed by black hole millions of years
ago? Most likely those in our Galaxy the ‘Milky Way’, they are still
there? If
one goes beyond our Solar System, the distances to the stars are
measured in light years (186,000 miles per second for one year= one
light yr.), which means we're looking back in time, many thousands of
years whenever we see a distant object in the Universe. How do we know
that what's there; matches what we see today? We
can view approximately 375 million stars in our own galaxy, if we were
to consider all 200-400 billion stars in our galaxy, a mean distance of
perhaps 40,000 light years away, there are perhaps only a few hundred
thousand that are already dead and the majority are on the far side of
the galaxy from where we are. To
further muddy the water, there are billions of Galaxies in the Universe
and tens of billions of stars amongst them. Likely, millions of these
stars no longer exist. PS. We
are not alone. and rest assured, we certainly will not likely look
similar, as there are millions and million of variables that make us
the way we appear and think.
Ellipticals
Elliptical
galaxies were denoted by the letter E and a number describing the galaxy's
apparent shape - 0 for a completely round form, 5 for one twice as long as
wide, and 7 for the apparently flattest genuine ellipticals. It is not known,
solely from an image, the actual true shape of such a galaxy; the same galaxy
might have quite different degrees of flattening if viewed from different
directions. Elliptical galaxies are, in general, characterized by old stellar
populations and very little of the gas and dust needed to form new stars.
They have a uniform luminosity and are similar to the bulge in a spiral
galaxy, but with no disk. The stars are old and there is no gas present.
These are small galaxies with no bulge and an ill-defined shape. "The
Magellenic clouds are examples". Lenticulars
They possess both a bulge
and a disk, but lack spiral arms. There is little or no gas and so all the
stars are old. They appear to be an intermediate. *Spirals
Fall into several classes
depending on their shape and the relative size of the bulge. Spiral galaxies
are characterized by the presence of gas in the disk which means star
formation remains active at the present time, hence the younger population of
stars. Spirals are divided into ordinary and barred spirals; in barred
systems the spiral arms arise from a straight ``bar" passing through the
center, while ordinary spirals have a more S-shaped inner configuration.
Ordinary spiral are denoted S and barred systems SB. Both usually contain a
central bulge, often sharing many properties with elliptical galaxies,
surrounded by a thin rotating disk containing whatever spiral structure there
may be. Spirals are subdivided into a sequence jointly defined by the winding
and prominence of the spiral arms, and the relative importance of the central
bulge. Spirals are usually found in the low density galactic field where
their delicate shape can avoid disruption by tidal forces from neighboring
galaxies. |
Q.T. Did you know that parts of the Rocky Mountains are still growing higher. |
'A'a: Hawaiian word used to describe a
lava flow whose surface is broken into rough angular fragments. Click here to
view a photo of 'a'a. Accessory: A mineral whose presence in a rock
is not essential to the proper classification of the rock. Accidental: Pyroclastic rocks that are formed
from fragments of non-volcanic rocks or from volcanic rocks not related to
the erupting volcano. Accretionary Lava Ball: A rounded mass, ranging in diameter
from a few centimeters to several meters, [carried] on the surface of a lava
flow (e.g., 'a'a) or on cinder-cone slopes [and formed] by the molding of
viscous lava around a core of already solidified lava. Acid: A descriptive term applied to
igneous rocks with more than 60% silica (SiO2). Active Volcano: A volcano that is erupting. Also, a
volcano that is not presently erupting, but that has erupted within historical
time and is considered likely to do so in the future. Agate: A variety of quartz distinguished
by its extremely fine grain size and bright colors. Agates may occur in
almost any kind of rock, but are especially common in volcanics. Agglutinate: A pyroclastic deposit consisting of
an accumulation of originally plastic ejecta and formed by the coherence of
the fragments upon solidification. Alkalic: Rocks which contain above average
amounts of sodium and/or potassium for the group of rocks for which it
belongs. For example, the basalts of the capping stage of Hawaiian volcanoes
are alkalic. They contain more sodium and/or potassium than the
shield-building basalts that make the bulk of the volcano. Andesite: Volcanic rock (or lava)
characteristically medium dark in color and containing 54 to 62 percent
silica and moderate amounts of iron and magnesium. Ash: Fine particles of pulverized rock
blown from an explosion vent. Measuring less than 1/10 inch in diameter, ash
may be either solid or molten when first erupted. By far the most common
variety is vitric ash (glassy particles formed by gas bubbles bursting
through liquid magma). Ashfall (Airfall): Volcanic ash that has fallen
through the air from an eruption cloud. A deposit so formed is usually well
sorted and layered. Ash Flow: A turbulent mixture of gas and rock
fragments, most of which are ash-sized particles, ejected violently from a
crater or fissure. The mass of pyroclastics is normally of very high
temperature and moves rapidly down the slopes or even along a level surface. Asthenosphere: The shell within the earth, some
tens of kilometers below the surface and of undefined thickness, which is a
shell of weakness where plastic movements take place to permit pressure
adjustments. Aquifer: A body of rock that contains
significant quantities of water that can be tapped by wells or springs. Avalanche: A large mass of material or
mixtures of material falling or sliding rapidly under the force of gravity.
Avalanches often are classified by their content, such as snow, ice, soil, or
rock avalanches. A mixture of these materials is a debris avalanche. Basalt: The commonest volcanic rock.
Basalt is very fine grained, has a smooth texture, and is quite black if
fresh. Weathered or altered basalt may be greenish black or various
rusty shades of brown, occasionally even brick red. Many specimens are full
of gas bubbles. Contains 45% to 54% silica, and generally is rich in iron and
magnesium. Basement: The undifferentiated rocks that
underlie the rocks of interest in an area. Basic: A descriptive term applied to
igneous rocks (basalt and gabbro) with silica (SiO2) between 44% and 52%. Bauxite: A type of laterite soil that is
very rich in aluminum and poor in iron. The best bauxites are nearly white. Bench: The unstable, newly-formed front of
a lava delta. Blister: A swelling of the crust of a lava
flow formed by the puffing-up of gas or vapor beneath the flow. Blisters are
about 1 meter in diameter and hollow. Block: Angular chunk of solid rock ejected
during an eruption. Bomb: Fragment of molten or semi-molten
rock, 2 1/2 inches to many feet in diameter, which is blown out during an
eruption. Because of their plastic condition, bombs are often modified in
shape during their flight or upon impact. Caldera: A basin-shaped volcanic depression;
by definition, at least a mile in diameter. Such large depressions are
typically formed by the subsidence of volcanoes. Crater Lake occupies the
best-known caldera in the Cascades. Capping Stage: Refers to a stage in the evolution
of a typical Hawaiian volcano during which alkalic, basalt, and related rocks
build a steeply, sloping cap on the main shield of the volcano. Eruptions are
less frequent, but more explosive. The summit caldera may be buried. Central Vent: A central vent is an opening at the
Earth's surface of a volcanic conduit of cylindrical or pipe-like form. Central Volcano: A volcano constructed by the
ejection of debris and lava flows from a central point, forming a more or
less symmetrical volcano. Chromite: A mineral composed of chromium
oxide. It is heavy and black and the only mineral source of chromium.
Chromite always occurs in peridotite or serpentinite. Cinder Cone: A volcanic cone built entirely of
loose fragmented material (pyroclastics.) Cirque: A steep-walled horseshoe-shaped
recess high on a mountain that is formed by glacial erosion. Cleavage: The breaking of a mineral along
crystallographic planes that reflects a crystal structure. Composite Volcano: A steep volcanic cone built by both
lava flows and pyroclastic eruptions. Compound Volcano: A volcano that consists of a
complex of two or more vents, or a volcano that has an associated volcanic
dome, either in its crater or on its flanks. Examples are Vesuvius and Mont
Pelee. Compression Waves: Earthquake waves that move like a
slinky. As the wave moves to the left, for example, it expands and compresses
in the same direction as it moves. Usage of compression waves. Conduit: A passage followed by magma in a
volcano. Continental Crust: Solid, outer layers of the earth,
including the rocks of the continents. Usage of continental crust. Continental Drift: The theory that horizontal movement
of the earth's surface causes slow, relative movements of the continents
toward or away from one another. Country Rocks: The rock intruded by and
surrounding an igneous intrusion. Crater: A steep-sided, usually circular
depression formed by either explosion or collapse at a volcanic vent. Craton: A part of the earth's crust that
has attained stability and has been little deformed for a prolonged period. Cretaceous: The interval of time between
135 and 70 million years before the present. Crust: The rigit outer part of the earth
extending down to a depth of about 60 miles. Curtain of Fire: A row of coalescing lava fountains
along a fissure; a typical feature of a Hawaiian-type eruption. Dacite: Volcanic rock (or lava) that
characteristically is light in color and contains 62% to 69% silica and
moderate a mounts of sodium and potassium. Debris Avalanche: A rapid and unusually sudden
sliding or flowage of unsorted masses of rock and other material. As applied
to the major avalanche involved in the eruption of Mount St. Helens, a rapid
mass movement that included fragmented cold and hot volcanic rock, water,
snow, glacier ice, trees, and some hot pyroclastic material. Most of the May
18, 1980 deposits in the upper valley of the North Fork Toutle River and in
the vicinity of Spirit Lake are from the debris avalanche. Debris Flow: A mixture of water-saturated rock
debris that flows downslope under the force of gravity (also called lahar or
mudflow). Detachment Plane: The surface along which a landslide
disconnects from its original position. Devonian: A period of time in the Paleozoic
Era that covered the time span between 400 and 345 million years. Diatreme: A breccia filled volcanic pipe that
was formed by a gaseous explosion. Dike: A sheetlike body of igneous rock
that cuts across layering or contacts in the rock into which it intrudes. Diorite: A coarsely granular rock composed
of milky crystals of feldspar and abundant grains of black hornblende or
mica. It some-what resembles granite except for being much darker and lacking
quartz. Like granite, it forms when molten magma cools deep within the
earth's crust. Dome: A steep-sided mass of viscous
(doughy) lava extruded from a volcanic vent (often circular in plane view)
and spiny, rounded, or flat on top. Its surface is often rough and blocky as
a result of fragmentation of the cooler, outer crust during growth of the
dome. Dormant Volcano: Literally, "sleeping."
The term is used to describe a volcano which is presently inactive but which
may erupt again. Most of the major Cascade volcanoes are believed to be
dormant rather than extinct. Drainage Basin: The area of land drained by a river
system. Echelon: Set of geologic features that are
in an overlapping or a staggered arrangement (e.g., faults). Each is
relatively short, but collectively they form a linear zone in which the
strike of the individual features is oblique to that of the zone as a whole. Ejecta: Material that is thrown out by a
volcano, including pyroclastic material (tephra) and lava bombs. Eocene: The period of time between about 60
and 40 million years before the present. Episode: An episode is a volcanic event that
is distinguished by its duration or style. Eruption: The process by which solid, liquid,
and gaseous materials are ejected into the earth's atmosphere and onto the
earth's surface by volcanic activity. Eruptions range from the quiet overflow
of liquid rock to the tremendously violent expulsion of pyroclastics. Eruption Cloud: The column of gases, ash, and
larger rock fragments rising from a crater or other vent. If it is of
sufficient volume and velocity, this gaseous column may reach many miles into
the stratosphere, where high winds will carry it long distances. Eruptive Vent: The opening through which volcanic
material is emitted. Evacuate: Temporarily move people away from
possible danger. Extinct Volcano: A volcano that is not presently
erupting and is not likely to do so for a very long time in the future. Usage
of extinct. Extrusion: The emission of magmatic material
at the earth's surface. Also, the structure or form produced by the process
(e.g., a lava flow, volcanic dome, or certain pyroclastic rocks). Fault: A crack or fracture in the earth's
surface. Movement along the fault can cause earthquakes or--in the process of
mountain-building--can release underlying magma and permit it to rise to the
surface. Fault Scarp: A steep slope or cliff formed
directly by movement along a fault and representing the exposed surface of
the fault before modification by erosion and weathering. Feldspar: An extremely common and abundant
family of minerals most which of which are rather milky in appearance. In
light-colored rocks the feldspars are commonly pink or white; in dark
-colored rocks they are usually either greenish or white. Fire fountain: See also: lava fountain Fissures: Elongated fractures or cracks on
the slopes of a volcano. Fissure eruptions typically produce liquid flows,
but pyroclastics may also be ejected. Flank Eruption: An eruption from the side of a
volcano (in contrast to a summit eruption.) Fluvial: Produced by the action of of
flowing water. Formation: A body of rock identified by lithic
characteristics and stratigraphic position and is mappable at the earth's
surface or traceable in the subsurface. Fracture: The manner of breaking due to
intense folding or faulting. Fumarole: A vent or opening through which
issue steam, hydrogen sulfide, or other gases. The craters of many dormant
volcanoes contain active fumaroles. Gabbro: A coarsely granular rock composed
of greenish white feldspar and black pyroxene. It is usually very dark in
color. Geothermal Energy: Energy derived from the internal
heat of the earth. Geothermal Power: Power generated by using the heat
energy of the earth. Graben: An elongate crustal block that is
relatively depressed (downdropped) between two fault systems. Granite: A granular rock composed of
crystals of glassy-looking quartz, milky feldspar, and black hornblende or
biotite. It forms when andesite magma cools very slowly beneath the surface. Greenstone: Volcanic rocks that have been
recrystallized at high temperature and pressure (metamorphosed). Their bright
green color is both startling and distinctive. Guyot: A type of seamount that has a
platform top. Named for a nineteenth-century Swiss-American geologist. Hardness: The resistance of a mineral to
scratching. Harmonic Tremor: A continuous release of seismic
energy typically associated with the underground movement of magma. It
contrasts distinctly with the sudden release and rapid decrease of seismic
energy associated with the more common type of earthquake caused by slippage
along a fault. Heat transfer: Movement of heat from one place to
another. Heterolithologic: Material is made up of a
heterogeneous mix of different rock types. Instead of being composed on one
rock type, it is composed of fragments of many different rocks. Holocene: The time period from 10,000 years
ago to the present. Also, the rocks and deposits of that age. Horizontal Blast: An explosive eruption in which the
resultant cloud of hot ash and other material moves laterally rather than
upward. Horst: A block of the earth's crust,
generally long compared to its width that has been uplifted along faults
relative to the rocks on either side. Hot Spot: A volcanic center, 60 to 120 miles
(100 to 200 km) across and persistent for at least a few tens of millions of
years, that is thought to be the surface expression of a persistent rising
plume of hot mantle material. Hot spots are not linked to arcs and may not be
associated with ocean ridges. Hot-spot Volcanoes: Volcanoes related to a persistent
heat source in the mantle. Hyaloclastite: A deposit formed by the flowing or
intrusion of lava or magma into water, ice, or water-saturated sediment and
its consequent granulation or shattering into small angular fragments. Hydrothermal Reservoir: An underground zone of porous rock
containing hot water. Hypabyssal: A shallow intrusion of magma or the
resulting solidified rock. Hypocenter: The place on a buried fault where
an earthquake occurs. Igneous Rock: A rock formed by cooling of a
molten magma either on the surface after it has erupted from a volcano or at
depth within the crust of the earth. Ignimbrite: The rock formed by the widespread
deposition and consolidation of ash flows and Nuees Ardentes. The term was
originally applied only to densely welded deposits but now includes
non-welded deposits. Intensity: A measure of the effects of an
earthquake at a particular place. Intensity depends not only on the magnitude
of the earthquake, but also on the distance from the epicenter and the local
geology. Intermediate: A descriptive term applied to
igneous rocks that are transitional between basic and acidic with silica
(SiO2) between 54% and 65%. Intrusion: The process of emplacement of magma
in pre-existing rock. Also, the term refers to igneous rock mass so formed
within the surrounding rock. Joint: A surface of fracture in a rock. Jurassic: The geologic period that began
about 180 million years before the present and ended about 135 million
years before the present. Juvenile: Pyroclastic material derived
directly from magma reaching the surface. Kipuka: An area surrounded by a lava flow. Laccolith: A body of igneous rocks with a flat
bottom and domed top. It is parallel to the layers above and below it. Lahar: A torrential flow of
water-saturated volcanic debris down the slope of a volcano in response to
gravity. A type of mudflow. Landsat: A series of unmanned satellites orbiting
at about 706 km (438 miles) above the surface of the earth. The satellites
carry cameras similar to video cameras and take images or pictures showing
features as small as 30 m or 80 m wide, depending on which camera is used. Lapilli: Literally, "little
stones." Round to angular rock fragments, measuring 1/10 inch to 2 1/2
inches in diameter, which may be ejected in either a solid or molten state. Laterite: A type of red soil that develops
under wet, tropical conditions. Most laterite soils are very deep and also
very infertile. Lava: Magma which has reached the
surface through a volcanic eruption. The term is most commonly applied to
streams of liquid rock that flow from a crater or fissure. It also refers to
cooled and solidified rock. Lava Dome: Mass of lava, created by many
individual flows, that has built a dome-shaped pile of lava. Lava Flow: An outpouring of lava onto the land
surface from a vent or fissure. Also, a solidified tongue like or sheet-like
body formed by outpouring lava. Lava Fountain: A rhythmic vertical fountain like
eruption of lava. Lava Lake (Pond): A lake of molten lava, usually
basaltic, contained in a vent, crater, or broad depression of a shield
volcano. Lava Shields: A shield volcano made of basaltic
lava. Lava Tube: A tunnel formed when the surface of
a lava flow cools and solidifies while the still-molten interior flows
through and drains away. Limu O Pele (Pele
Seaweed): Delicate,
translucent sheets of spatter filled with tiny glass bubbles. Limestone: Limestone is a sedimentary rock
composed of the mineral calcite (calcium carbonate). The primary source of
this calcite is usually marine organisms. These organisms secrete shells that
settle out of the water column and are deposited on ocean floors as pelagic
ooze Lithic: Of or pertaining to stone. Lithosphere: The rigid crust and uppermost
mantle of the earth. Thickness is on the order of 60 miles (100 km). Stronger
than the underlying asthenosphere. Luster: The reflection of light from the
surface of a mineral. Maar: A volcanic crater that is produced
by an explosion in an area of low relief, is generally more or less circular,
and often contains a lake, pond, or marsh. Mafic: An igneous composed chiefly of one
or more dark-colored minerals. Magma: Molten rock beneath the surface
of the earth. Magma Chamber: The subterranean cavity containing
the gas-rich liquid magma which feeds a volcano. Magmatic: Pertaining to magma. Magnitude: A numerical expression of the
amount of energy released by an earthquake, determined by measuring
earthquake waves on standardized recording instruments (seismographs.) The
number scale for magnitudes is logarithmic rather than arithmetic. Therefore,
deflections on a seismograph for a magnitude 5 earthquake, for example, are
10 times greater than those for a magnitude 4 earthquake, 100 times greater
than for a magnitude 3 earthquake, and so on. Mantle: The zone of the earth below the
crust and above the core. Marine Rocks: Rocks that formed in seawater. Matrix: The solid matter in which a fossil
or crystal is embedded. Also, a binding substance (e.g., cement in concrete). Mesozoic: The era of geologic time comprising
the Triassic, Jurassic and Cretaceous periods. Mesozoic time began about 225
million years before the present and ended about 70 million years before the
present. Metamorphism: The process of recrystallizing
rocks under conditions of high temperature and pressure and converting them
(Recrystallizing) into new kinds of rock. Mica: A family of common minerals which
may be either black or colorless but are always flaky. Especially abundant in
granites and similar rocks. Miocene: An epoch in Earth's history from
about 24 to 5 million years ago. Also refers to the rocks that formed in that
epoch. Moho: Also called the Mohorovicic
discontinuity. The surface or discontinuity that separates the crust from the
mantle. The Moho is at a depth of 5-10 km beneath the ocean floor and about
35 km below the continents (but down to 60 km below mountains). Named for
Andrija Mohorovicic, a Croatian seismologist. Monogenetic: A volcano built by a single
eruption. Mudflow: A flowage of water-saturated earth
material possessing a high degree of fluidity during movement. A
less-saturated flowing mass is often called a debris flow. A mudflow
originating on the flank of a volcano is properly called a lahar. Mudstone: A sedimentary rock that started out
as mud. Nuees Ardentes: A French term applied to a highly
heated mass of gas-charged ash which is expelled with explosive force and moves
hurricane speed down the mountainside. Obsidian: A black or dark-colored volcanic
glass usually composed of rhyolite. Obligocene: The geologic period that started
about 40 million years before the present and ended about 14 million years
before the present. Olivine: A pale green mineral which occurs
in small crystals scattered through black ingneous rocks. Peridotite always
contains olivine and so do some varieties of basalt and gabbro. Oceanic Crust: The earth's crust where it
underlies oceans. Pali: Hawaiian word for steep hills or
cliffs. Pele Hair: A natural spun glass formed by
blowing-out during quiet fountaining of fluid lava, cascading lava falls, or
turbulent flows, sometimes in association with pele tears. A single strand,
with a diameter of less than half a millimeter, may be as long as two meters.
Pele Tears: Small, solidified drops of volcanic
glass behind which trail pendants of Pele hair. They may be tear-shaped,
spherical, or nearly cylindrical. Peralkaline: Igneous rocks in which the molecular
proportion of aluminum oxide is less than that of sodium and potassium oxides
combined. Peridotite: A heavy,. black rock that forms
most of the earth's interior. It is composed principally of black pyroxene
and green olivine. Perlite: A glassy form of rhyolite that
contains some water. Most perlite is rather greenish but it comes in other
colors. It puffs up like popcorn upon roasting to make lightweight chunks
useful as a soil additive and in making special purpose concrete. Phenocryst: A conspicuous, usually large,
crystal embedded in porphyritic igneous rock. Phreatic Eruption
(Explosion): An
explosive volcanic eruption caused when water and heated volcanic rocks interact
to produce a violent expulsion of steam and pulverized rocks. Magma is not
involved. Phreatomagmatic: An explosive volcanic eruption that
results from the interaction of surface or subsurface water and magma. Pillow lava: Interconnected, sack-like bodies of
lava formed underwater. Pipe: A vertical conduit through the
Earth's crust below a volcano, through which magmatic materials have passed.
Commonly filled with volcanic breccia and fragments of older rock. Pit Crater: A crater formed by sinking in of
the surface, not primarily a vent for lava. Plagioclase: A variety of feldspar which
contains sodium and potassium. Plastic: Capable of being molded into any
form, which is retained. Plates: One of the rigid slabs that make
the outer crust of the earth. Plates are about 60 miles thick and most of
them cover areas of many hundreds of square miles. Plate Tectonics: The theory that the earth's crust
is broken into about 10 fragments (plates,) which move in relation to one
another, shifting continents, forming new ocean crust, and stimulating
volcanic eruptions. Pleistocene: A epoch in Earth history from about
2-5 million years to 10,000 years ago. Also refers to the rocks and sediment
deposited in that epoch. Plinian Eruption: An explosive eruption in which a
steady, turbulent stream of fragmented magma and magmatic gases is released
at a high velocity from a vent. Large volumes of tephra and tall eruption
columns are characteristic. Plug: Solidified lava that fills the
conduit of a volcano. It is usually more resistant to erosion than the
material making up the surrounding cone, and may remain standing as a
solitary pinnacle when the rest of the original structure has eroded away. Plug Dome: The steep-sided, rounded mound
formed when viscous lava wells up into a crater and is too stiff to flow
away. It piles up as a dome-shaped mass, often completely filling the vent
from which it emerged. Pluton: A large igneous intrusion formed at
great depth in the crust. Polygenetic: Originating in various ways or from
various sources. Precambrian:All geologic time from the beginning
of Earth history to 570 million years ago. Also refers to the rocks that
formed in that epoch. Pumice: Light-colored, frothy volcanic
rock, usually of dacite or rhyolite composition, formed by the expansion of
gas in erupting lava. Commonly seen as lumps or fragments of pea-size and
larger, but can also occur abundantly as ash-sized particles. Usage of pumice.
Pyroclastic: Pertaining to fragmented (clastic)
rock material formed by a volcanic explosion or ejection from a volcanic
vent. Pyroclastic Flow: Lateral flowage of a turbulent
mixture of hot gases and unsorted pyroclastic material (volcanic fragments,
crystals, ash, pumice, and glass shards) that can move at high speed (50 to
100 miles an hour.) The term also can refer to the deposit so formed. Quartz: The commonest of all minerals. It
comes in a variety of colors and disguises, but usually occurs in clear,
glassy grains. Quartz is the mineral form of silica. Quaternary: The period of Earth's history from
about 2 million years ago to the present; also, the rocks and deposits of
that age. Radiocarbon Dating: A method of determining the age of
specimens of organic material by analysing their content of carbon-14 which
is weakly radioactive. The method only works on objects less than about
40,000 years old, so geologist rarely use it. Relief: The vertical difference between the
summit of a mountain and the adjacent valley or plain. Renewed Volcanism State: Refers to a state in the evolution
of a typical Hawaiian volcano during which --after a long period of
quiescence--lava and tephra erupt intermittently. Erosion and reef building
continue. Repose: The interval of time between
volcanic eruptions. Rhyodacite: An extrusive rock intermediate in
composition between dacite and rhyolite. Rhyolite: Volcanic rock (or lava) that
characteristically is light in color, contains 69% silica or more, and is
rich in potassium and sodium. Ridge, Oceanic: A major submarine mountain range. Rift System: The oceanic ridges formed where
tectonic plates are separating and a new crust is being created; also, their
on-land counterparts such as the East African Rift. Rift Zone: A zone of volcanic features associated
with underlying dikes. The location of the rift is marked by cracks, faults,
and vents. Ring of Fire: The regions of mountain-building
earthquakes and volcanoes which surround the Pacific Ocean. Sandstone: A common sedimentary rock that was
originally sand. Scoria: A bomb-size (> 64 mm) pyroclast
that is irregular in form and generally very vesicular. It is usually
heavier, darker, and more crystalline than pumice. Seafloor Spreading: The mechanism by which new seafloor
crust is created at oceanic ridges and slowly spreads away as plates are
separating. Seamount: A submarine volcano. Seismograph: An instrument that records seismic
waves; that is, vibrations of the earth. Seismologist: Scientists who study earthquake
waves and what they tell us about the inside of the Earth. Usage of seismologist.
Seismometer: An instrument that measures motion
of the ground caused by earthquake waves. Serpentinite: A dark, greenish rock that is
usually fairly soft and rather greasy looking. Many specimens feel soapy
because they contain some talc. Serpentinite forms by the reaction of
peridotite with water. It forms an important part of the oceanic crust. Shearing: The motion of surfaces sliding past
one another. Shear Waves: Earthquake waves that move up and
down as the wave itself moves. For example, to the left. Usage of shear
waves. Shield Volcano: A gently sloping volcano (very low
profile) in the shape of a flattened dome and built almost exclusively of
lava flows. Shoshonite: A trachyandesite composed of
olivine and augite phenocrysts in a groundmass of labradorite with alkali
feldspar rims, olivine, augite, a small amount of leucite, and some
dark-colored glass. Its name is derived from the Shoshone River, Wyoming and
given by Iddings in 1895. Silica: A chemical combination of silicon
and oxygen. Sill: A tabular body of intrusive igneous
rock, parallel to the layering of the rocks into which it intrudes. Skylight: An opening formed by a collapse in
the roof of a lava tube. Solfatara: A type of fumarole, the gases of
which are characteristically sulfurous. Spatter Cone: A low, steep-sided cone of spatter
built up on a fissure or vent. It is usually of basaltic material. Spatter Rampart: A ridge of congealed pyroclastic
material (usually basaltic) built up on a fissure or vent. Specific Gravity: The density of a mineral divided by
the density of water. Spines: Horn-like projections formed upon a
lava dome. Stalactite: A cone shaped deposit of minerals
hanging from the roof of a cavern. Stratigraphic: The study of rock strata,
especially of their distribution, deposition, and age. Stratovolcano: A volcano composed of both lava
flows and pyroclastic material. Streak: The color of a mineral in the
powdered form. Strike-Slip Fault: A nearly vertical fault with
side-slipping displacement. Strombolian Eruption: A type of volcanic eruption
characterized by jetting of clots or fountains of fluid basaltic lava from a
central crater. Subduction Zone: The zone of convergence of two
tectonic plates, one of which usually overrides the other. Surge: A ring-shaped cloud of gas and
suspended solid debris that moves radially outward at high velocity as a
density flow from the base of a vertical eruption column accompanying a
volcanic eruption or crater formation. Talus: A slope formed a the base of a
steeper slope, made of fallen and disintegrated materials. Tephra: Materials of all types and sizes
that are erupted from a crater or volcanic vent and deposited from the air. Tephrochronology: The collection, preparation,
petrographic description, and approximate dating of tephra. Tertiary: The period between the end of the
Cretaceous and the end of the Pliocene time. The Teritiary period began about
70 million years before the present and ended about 3 million year before the
present. Tilt: The angle between the slope of a
part of a volcano and some reference. The reference may be the slope of the
volcano at some previous time. Trachyandesite: An extrusive rock intermediate in
composition between trachyte and andesite. Trachybasalt: An extrusive rock intermediate in
composition between trachyte and basalt. Trachyte: A group of fine-grained, generally
porphyritic, extrusive igneous rocks having alkali feldspar and minor mafic
minerals as the main components, and possibly a small amount of sodic
plagioclase. Tremor: Low amplitude, continuous
earthquake activity often associated with magma movement. Triassic: The period of geologic time that
began about 225 years before the present and ended about 180 million years
before the present. Tsunami: A great sea wave produced by a
submarine earthquake, volcanic eruption, or large landslide. Tuff: Rock formed of pyroclastic material.
Tuff Cone: A type of volcanic cone formed by
the interaction of basaltic magma and water. Smaller and steeper than a tuff
ring. Tuff Ring: A wide, low-rimmed, well-bedded
accumulation of hyalo-clastic debris built around a volcanic vent located in a
lake, coastal zone, marsh, or area of abundant ground water. Tumulus: A doming or small mound on the
crest of a lava flow caused by pressure due to the difference in the rate of
flow between the cooler crust and the more fluid lava below. Ultramafic: Igneous rocks made mostly of the
mafic minerals hypersthene, augite, and/or olivine. Unconformity: A substantial break or gap in the
geologic record where a rock unit is overlain by another that is not next in
stratigraphic sucession, such as an interruption in continuity of a
depositional sequence of sedimentary rocks or a break between eroded igneous
rocks and younger sedimentary strata. It results from a change that caused
deposition to cease for a considerable time, and it normally implies uplift
and erosion with loss of the previous formed record. Vent: The opening at the earth's surface
through which volcanic materials issue forth. Vesicle: A small air pocket or cavity formed
in volcanic rock during solidification. Viscosity: A measure of resistance to flow in
a liquid (water has low viscosity while honey has a higher viscosity.) Volcano: A vent in the surface of the Earth
through which magma and associated gases and ash erupt; also, the form or
structure (usually conical) that is produced by the ejected material. Volcanic Arc: A generally curved linear belt of
volcanoes above a subduction zone, and the volcanic and plutonic rocks formed
there. Volcanic Complex: A persistent volcanic vent area
that has built a complex combination of volcanic landforms. Volcanic Cone: A mound of loose material that was
ejected ballistically. Volcanic Neck: A massive pillar of rock more
resistant to erosion than the lavas and pyroclastic rocks of a volcanic cone.
Vulcanian: A type of eruption consisting of
the explosive ejection of incandescent fragments of new viscous lava, usually
on the form of blocks. ("Vulcan" was the Roman god of fire) Weathering: The complex of processes that
combine to decompose solid rock into soil. Water Table: The surface between where the pore
space in rock is filled with water and where the pore space in rock is filled
with air. Xenocrysts: A crystal that resembles a
phenocryst in igneous rock, but is a foreign to the body of rock in which it
occurs. |
Facts and Fiction
Another
ponder relating to the cause Earths increase in global warming is to ask? At
which point is our Sun (which has as a direct correlation to Planet Earth’s
environment) in its 200 million year journey around the Milky Way Galaxy, and
is it about to get warmer or colder in the next 200 years? The Sun is now 6%
warmer today than it was 650 million years ago, a long time before the
arrival of mammals and their pollution. It is held in the scientific
community that our Sun is approximately half way (+or- a billion years)
through it's solar life. The Earth will become a
global desert, carbon dioxide levels will drop and there would not be enough
carbon dioxide to support photosynthesis, and most plants would die. Remaining plants would not be sufficient to support a biosphere, so while the entire planet might incinerated in a few billion years, or cast off into a deep freeze, it's possible that life on Earth could be a dead planet in about half a billion years.
|
OCEAN LEVELS |
Global mean sea level has risen about 8–9 inches (21–24 centimeters) since 1880, with about a third of that coming in just the last two and a half decades. The rising water level is mostly due to a combination of melt water from glaciers and ice sheets and thermal expansion of seawater as it warms. In 2020, global mean sea level was 91.3 millimeters (3.6 inches) above the 1993 average, making it the highest annual average in the satellite record (1993-present). The global mean water level in the ocean rose by 0.14 inches (3.6 millimeters) per year from 2006–2015, which was 2.5 times the average rate of 0.06 inches (1.4 millimeters) per year throughout most of the twentieth century. By the end of the century, global mean sea level is likely to rise at least one foot (0.3 meters) above 2000 levels, even if greenhouse gas emissions follow a relatively low pathway in coming decades. In some ocean basins, sea level has risen as much as 6-8 inches (15-20 centimeters) since the start of the satellite record. Regional differences exist because of natural variability in the strength of winds and ocean currents, which influence how much and where the deeper layers of the ocean store heat.
Global sea level has been rising over the past century, and the rate has increased in recent decades. In 2014, global sea level was 2.6 inches above the 1993 average—the highest annual average in the satellite record (1993-present). Sea level continues to rise at a rate of about one-eighth of an inch per year. The two major causes of global sea level rise are thermal expansion caused by warming of the ocean (since water expands as it warms) and increased melting of land-based ice, such as glaciers and ice sheets. The ocean is absorbing more than 90 percent of the increased atmospheric heat associated with emissions from human activity. With continued ocean and atmospheric warming, sea levels will likely rise for many centuries at rates higher than that of the current century. In the United States, almost 40 percent of the population lives in relatively high-population-density coastal areas, where sea level plays a role in flooding, shoreline erosion, and hazards from storms. Globally, eight of the world's 10 largest cities are near a coast,The difference between global and local sea level sea level trends are different measurements. Just as the surface of the Earth is not flat, the surface of the ocean is also not flat—in other words, the sea surface is not changing at the same rate globally. Sea level rise at specific locations may be more or less than the global average due to many local factors: subsidence, upstream flood control, erosion, regional ocean currents, variations in land height, and whether the land is still rebounding from the compressive weight of Ice Age glaciers.Sea level is primarily measured using tide stations and satellite laser altimeters. Tide stations around the globe tell us what is happening at a local level—the height of the water as measured along the coast relative to a specific point on land. Satellite measurements provide us with the average height of the entire ocean. Taken together, these tools tell us how our ocean sea levels are changing over time. |
|
Hurricanes
draw their energy from the warm surface water of the tropics, which explains
why hurricanes dissipate rapidly once they move over cold water or large land
masses The global wind pattern is
also known as the "general circulation" and the surface winds of
each hemisphere are divided into three wind belts: -Polar Easterlies = from
60-90 degrees latitude.
"Super-typhoon" is a term utilized by the U.S. Joint Typhoon Warning
Center for typhoons that reach maximum sustained 1-minute surface winds of at
least 65 m/s (130 kt, 150 mph). This is the equivalent of a strong
Saffir-Simpson category 4 or category 5 hurricane in the Atlantic basin or a
category 5 severe tropical cyclone in the Australian basin. "Major
hurricane/Intense hurricane" is a term utilized by the National Hurricane Center for
hurricanes that reach maximum sustained 1-minute surface winds of at least 50
m/s (96 kt, 111 mph). This is the equivalent of category 3, 4 and 5 on the
Saffir-Simpson scale. Hurricanes rotate in a
counterclockwise direction around an "eye." A tropical storm
becomes a hurricane when winds reach 74 mph. There are on average six
Atlantic hurricanes each year; over a three-year period, approximately five
hurricanes strike the United States coastline from Texas to Maine. The
Atlantic hurricane season begins June 1 and ends November 30. The East
Pacific hurricane season runs from May 15 through November 30, with peak
activity occurring during July through September. When hurricanes move onto
land, the heavy rain, strong winds and heavy waves can damage buildings,
trees and cars. The heavy waves are called a storm surge. Storm surge is very
dangerous and a major reason why you MUST stay away from the ocean during a
hurricane. |
LAHAR |
Scientists
often use more specific terms than lahar when referring to moving masses of
water and rock debris
Dense flows that consist of
a relatively high percentage of coarse rock particles are debris flows. The
size of sediment transported by debris flows ranges in size from clay and
silt (less than 0.06 mm) to boulders as large as 10 m in diameter. A typical
debris flow consists of about 2 parts sediment for every one part water.
Thus, debris flows may consist of more than 80 percent sediment by weight! Mudflow:
A debris flow composed of
relatively small rock particles, dominantly sand and silt-sized particles (less
than 2 mm in diameter), is often called a mudflow. Even though mudflows can
transport large boulders and can have sediment concentrations as great as
debris flows, their sediment composition typically consists of at least 50
percent sand, silt, and clay-size particles ("mud" refers to silt-
and clay-size particles). Mudflow is probably the most familiar and commonly
used term by nonscientists to describe dense mixtures of flowing sediment and
water. Hyperconcentrated
Streamflow:
A flow containing between
40 and 80 percent sediment by weight is often referred to as
hyperconcentrated streamflow. Debris flows and mudflows represent the most
dense and concentrated mixtures of flowing sediment and water; they commonly
are composed of more than 80 percent sediment by weight. Normal streamflow,
which may contain as much as 40 percent sediment by weight, is the least
dense and concentrated mixture of flowing sediment and water.
Hyperconcentrated flows are finer grained than debris flows and mudflows,
usually consisting of predominantly of sand-size particles. As a debris flow
or mudflow moves down a river valley, they will eventually become more dilute
by mixing with water in the river and by losing some of the sediment. When
the percentage of sediment by weight drops below 80 percent, the flow
transforms into hyperconcentrate streamflow. Cohesive
Lahars:
Debris flows or mudflows
that contain more than 3 to 5 percent of clay-size sediment are sometimes
referred to as cohesive lahars. Scientists may sometimes conclude that a
relatively high concentration of clay in these flows indicates it began as a
large landslide from the flank of a volcano. The interior parts of many
volcanoes have been hydrothermally altered and consist of many clay
particles. Non-cohesive
Lahars"
Debris flows or mudflows
that contain less than 3 to 5 percent of clay-size sediment are sometimes
referred to as non-cohesive lahars. Such a relatively low proportion of clay
in this volcanic debris is considered by some scientists to be evidence that the
lahar did not originate as a volcanic landslide, but rather in another way.
For example, by the mixing of water melted from snow and ice with volcanic
debris.
As a lahar rushes
downstream from a volcano, its size, speed, and the amount of water and rock
debris it carries constantly change. The beginning surge of water and rock
debris often erodes rocks and vegetation from the side of a volcano and along
the river valley it enters. This initial flow can also incorporate water from
melting snow and ice (if present) and the river it overruns. By eroding rock
debris and incorporating additional water, lahars can easily grow to more
than 10 times their initial size. But as a lahar moves farther away from a
volcano, it will eventually begin to lose its heavy load of sediment and
decrease in size. Eruptions
may trigger one or more lahars directly by quickly melting snow and ice on a
volcano or ejecting water from a crater lake. More often, lahars are formed
by intense rainfall during or after an eruption--rainwater can easily erode
loose volcanic rock and soil on hillsides and in river valleys. Some of the
largest lahars begin as landslides of saturated and hydrothermally altered
rock on the flank of a volcano or adjacent hillslopes. Landslides are
triggered by eruptions, earthquakes, precipitation, or the unceasing pull of
gravity on the volcano. Lahars racing down river
valleys and spreading across flood plains tens of kilometers downstream from
a volcano often cause serious economic and environmental damage. The direct
impact of a lahar's turbulent flow front or from the boulders and logs
carried by the lahar can easily crush, abrade, or shear off at ground level
just about anything in the path of a lahar. Even if not crushed or carried
away by the force of a lahar, buildings and valuable land may become
partially or completely buried by one or more cement-like layers of rock
debris. By destroying bridges and key roads, lahars can also trap people in
areas vulnerable to other hazardous volcanic activity, especially if the
lahars leave deposits that are too deep, too soft, or too hot to cross. After a volcanic eruption,
the erosion of new loose volcanic deposits in the headwaters of rivers can
lead to severe flooding and extremely high rates of sedimentation in areas
far downstream from a volcano. Over a period of weeks to years, post-eruption
lahars and high-sediment discharges triggered by intense rainfall frequently
deposit rock debris that can bury entire towns and valuable agricultural
land. Such lahar deposits may also block tributary stream valleys. As the
area behind the blockage fills with water, areas upstream become inundated.
If the lake is large enough and it eventually overtops or breaks through the
lahar blockage, a sudden flood or a lahar may bury even more communities and
valuable property downstream from the tributary. |
QT.
billionth of a second = Nanosecond |
Lithium Batteries |
The most common type of lithium cell
used in consumer applications uses metallic lithium as the anode and manganese
dioxide as the cathode, with a salt of lithium dissolved in an organic solvent
as the electrolyte. Lithium batteries (Science) are primary
batteries that have metallic lithium as an anode. These types of
batteries are also referred to as lithium-metal batteries .
They stand apart from other
batteries in their high charge density and high cost per unit. Depending on the design and
chemical compounds used, lithium cells can produce voltages from 1.5 V
(comparable to a zinc–carbon or alkaline battery) to about 3.7 V. The
price of lithium-ion batteries has fallen steeply as their production scale has
increased and manufacturers have developed more cost-effective methods. Recycling
can help reduce the need to search for battery materials. Cobalt is fully
recyclable and roughly 15
percent of U.S. cobalt consumption is from recycled scrap
today. Disposable primary
lithium batteries must be distinguished from secondary lithium-ion or a lithium-polymer, which are rechargeable batteries. Lithium
is especially useful, because its ions can be arranged to move between the
anode and the cathode, using an intercalated lithium compound as the cathode material but without using
lithium metal as the anode material. Pure lithium will instantly react with
water, or even moisture in the air; the lithium in lithium-ion batteries is in
a less reactive compound.
First, companies must be held
accountable for enacting and enforcing policies to only use ethically-sourced
materials. Some companies are off to a good start. Tesla, for example, has
committed to sourcing materials only from North America for its battery
production facility and battery supplier LG Chem claims they have stopped using
conflict-sourced cobalt.
Battery technology is continuing to improve. Lithium-titanate and lithium-iron-phosphate, for example, are gaining importance in the EV market and don’t need cobalt. Other battery chemistries that rely on magnesium, sodium, or lithium-sulfur are also gaining traction as they have the potential to beat lithium-ion batteries on energy density and cost.
Lithium batteries are widely used in
portable consumer electronic devices. The term "lithium battery"
refers to a family of different lithium-metal chemistries, comprising many
types of cathodes and electrolytes but all with metallic lithium as the anode.
The battery requires from 0.15 to 0.3 kg of lithium per kWh. |
LASER |
Today
scientists, lab technicians, engineers, and industrial technicians regularly utilize
lasers to perform a wide range of important tasks. They measure distances,
both short and long, with lasers, giving astronomers, geographers, and
surveyors much more accurate figures than were available before the invention
of these devices. They also use lasers to drill, weld, cut, and mark all
sorts of materials; to study microscopic objects, including molecules; and in
solving crimes. The first working laser was built by Theodor Harold Maiman
working at Hughes Research Laboratories in Malibu California, but the first
patent was issued to Bell Laboratories in 1960. Laser light
is also characteristically monochromatic and coherent, which means all the
photons produced are of the same wavelength and therefore color. Light
emitted from a laser is usually emitted in a near parallel beam and the
wavelength of the photons varies depending upon the type of laser and is not
necessarily in the spectrum of visible light. The photons are traveling in the
same direction and are in phase meaning the peaks and valleys of their
electromagnetic waves coincide. A laser
basically consists of two main parts, an energy input and a gain medium. The
energy input is called a pump source, the pump source could be an
electrical power supply, a chemical reaction or another laser. The power
source inputs energy which is called laser pumping energy, this is what
drives the process which produces the laser light. The pumping
energy is directed into the gain medium, this is the material which gives
different lasers their individual characteristics. There are many different
materials used as gain media including crystalline solids usually doped with
transition metal ions or rare earth ions, gases such as CO2 or He,
semiconductors such as gallium arsenide and liquids dyes. When energy
is pumped into the gain medium it causes the particles in the medium to go
into an excited state. Particle in this excited state may drop back to their ground
state and when this happens they release their extra energy in the form of a
photon of a specific wavelength. This photon may then collide with another
particle, if this particle is in its ground state it will absorb the photon
and become excited, if the particle is already excited the photon will cause
it to drop to its ground state thus emitting another photon, this is called
stimulated emission. Photons produced by stimulated emission are very similar
to the initial photon in terms of wavelength, phase and polarization; this is
what gives laser light its characteristics. If energy
continues to be put into the gain medium then it will reach a state where
there are more of the particles are excited then in the ground state, this is
called population inversion. This means that a photon passing through the
medium has more chance of causing stimulated emission then of being absorbed,
the laser is therefore acting as a light amplifier. Mirrors are placed at the
front and back of the gain medium. The mirror at the back is fully reflective
but the one at the front is only partially reflective. These mirrors will
cause photons emitted to pass through the medium many times until they pass
through the front mirror and are emitted in the laser beam. This will increase
the chance of photons colliding with particles and continuing the chain
reaction. The maser which was the predecessor of
the laser and emitted microwaves. Bell labs original worked with infrared
frequencies but later changed their focus to visible light and the
optical maser which was how the laser was first referred to. There are now
many used for the use of lasers in Industry: such as in precise cutting of
flat materials. Lasers have the advantage that there is no physical contact
with the material so there is no chance of contamination, also there is less
chance of the material warping as the laser energy can be focused on a very
small area so the whole material is not heated. In
Astromony: In the past
Astronomers were used to working with images that are blurred by the Earth's
atmosphere. However, a laser virtual star, launched from the W.M. Keck Observatory telescope,
can be used to correct the atmosphere's distortions and clear up the picture.
This new technology, called Laser Guide Star adaptive optics, will lead to
important advances for the study of planets in our solar system and outside
of our solar system, as well as galaxies, black holes, and how the universe
formed. In
electronics, lasers are used to read the bumps on the surface
of a compact disk. The surface of the disk is made up of bumps and lands,
when a laser is shone onto the surface it will reflect off the surface at
different angles depending upon whether it hits a bump or land. A detector
will then record where the laser is reflected and use this information to
read the information on the disk. Lasers can
measure enormous distances with great accuracy. A laser beam travels at a
constant speed (the speed of light). The time it takes a laser beam to travel
from its source, reflect off an object, and return to the source, will
indicate the exact distance between the source and the object. Lasers in industry are used to cut, drill, weld,
heat-treat, and otherwise alter both metals and nonmetals. Lasers can drill
tiny holes in turbine blades more quickly and less expensively than
mechanical drills. Lasers have several advantages over conventional
techniques of cutting materials. For one thing, unlike saw blades or knife
blades, lasers never get dull. For another, lasers make cuts with better edge
quality than most mechanical cutters. The edges of metal parts cut by a laser
rarely need to be filed or polished because the laser makes such a clean cut. |
|
A rusty object doesn't lose weight, but gains weight. The rusting object attracts particles in the air, this matter can be transformed, but not eliminated. |
Motion is relative
All motion is relative to
the observer or to some fixed object. When you see a car drive by, it is
moving with respect to you. If you are in a car that is going at the same
speed, the other car will not by moving with respect to you. But both cars
are moving with respect to the ground. Using the Sun as an example, it is not
moving across the sky (although it is traveling through the Milky Way
galaxy), the Planet Earth is. We consider motion with respect to the ground
or the Earth. Within the Universe there is no real fixed point. The basis for
Einstein's Theory of Relativity is that all motion is relative to what
you define as a fixed point. First Law of Motion: Law
of Inertia
Every object in a state of uniform motion tends to
remain in that state of motion unless an external force is applied to it. Second Law of Motion: The relationship between an
object's mass m, its acceleration a, and the applied force f is
F=ma. This is the most powerful
of Newton's three Laws, because it allows quantitative calculations of
dynamics: how do velocities change when forces are applied. Notice the
fundamental difference between Newton's 2nd Law and the dynamics of
Aristotle: according to Newton, a force causes only a change in velocity (an
acceleration); it does not maintain the velocity as Aristotle held. This is sometimes
summarized by saying that under Newton, F
= ma, but under Aristotle F
= mv, where v
is the velocity. Thus, according to Aristotle there is only a velocity if
there is a force, but according to Newton an object with a certain velocity
maintains that velocity unless
a force acts on it to cause an acceleration. Aristotle's view seems to
be more in accord with common sense, but that is because of a failure to
appreciate the role played by frictional forces. Once account is taken of all forces acting in a
given situation it is the dynamics of Galileo and Newton, not of Aristotle,
that are found to be in accord with the observations. Third
Law of Motion: For Every action there is
an equal and opposite reaction. -Measurement
In order to determine how
fast an object is going, you measure the time it takes to cover a given
distance, using the equation d
= vt where:
From this equation, you can
get the equation for velocity as v = d/t. Velocity (v) or speed
equals the distance (d) traveled divided by the time (t) it
takes to go that distance. We distinguish between
speed and velocity because if you add the speeds of objects, their directions
are important. For example, the velocity of an airplane with respect to the
ground would vary according to the direction of the wind. -Acceleration is the
increase of velocity over a period of time. Deceleration is the decrease of
velocity. When you start running, you accelerate (increase your velocity)
until you reach a constant speed. Mathematically,
acceleration is the change in velocity divided by the time for the change a
= (v2 − v1)/(t2 − t1) where:
Often this is written as a
= Δv/Δt, where Δ is the Greek letter delta and
stands for difference. |
Multicellular animals must continually
monitor and maintain a constant internal environment as well as monitor and
respond to an external environment. In most, these two functions are
coordinated by two integrated and coordinated organ systems: the nervous
system and the endocrine system. Three basic functions are
performed by nervous systems:
Sensory
Input
Receptors are parts of the nervous
system that sense changes in the internal or external environments. Sensory
input can be in many forms, including pressure, taste, sound, light, blood
pH, or hormone levels that are converted to a signal and sent to the brain or
spinal cord. Integration
and Output
In the sensory centers of
the brain or in the spinal cord, the barrage of input is integrated and a
response is generated. The response, a motor output, is a signal transmitted
to organs than can convert the signal into some form of action, such as
movement, changes in heart rate, release of hormones, etc. Endocrine
Systems
Some animals have a second
control system, the endocrine system. The nervous system coordinates rapid
responses to external stimuli. The endocrine system controls slower, longer
lasting responses to internal stimuli. Activity of both systems is
integrated. Divisions of the Nervous System:
The nervous system monitors
and controls almost every organ system through a series of positive and
negative feedback loops.The Central Nervous System (CNS) includes the brain
and spinal cord. The Peripheral Nervous System (PNS) connects the CNS to
other parts of the body, and is composed of nerves (bundles of neurons). Not all animals have highly
specialized nervous systems. Those with simple systems tend to be either
small and very mobile or large and immobile. Large, mobile animals have
highly developed nervous systems: the evolution of nervous systems must have
been an important adaptation in the evolution of body size and mobility. Coelenterates, cnidarians,
and echinoderms have their neurons organized into a nerve net. These
creatures have radial symmetry and lack a head. Although lacking a brain or
either nervous system (CNS or PNS) nerve nets are capable of some complex
behavior. Bilaterally symmetrical
animals have a body plan that includes a defined head and a tail region.
Development of bilateral symmetry is associated with cephalization, the
development of a head with the accumulation of sensory organs at the front
end of the organism. Flatworms have neurons associated into clusters known as
ganglia, which in turn form a small brain. Vertebrates have a spinal cord in
addition to a more developed brain. Chordates have a dorsal
rather than ventral nervous system. Several evolutionary trends occur in
chordates: spinal cord, continuation of cephalization in the form of larger
and more complex brains, and development of a more elaborate nervous system.
The vertebrate nervous system is divided into a number of parts. The central
nervous system includes the brain and spinal cord. The peripheral nervous
system consists of all body nerves. Motor neuron pathways are of two types:
somatic (skeletal) and autonomic (smooth muscle, cardiac muscle, and glands).
The autonomic system is subdivided into the sympathetic and parasympathetic
systems. Neurons
Nervous tissue is composed
of two main cell types: neurons and glial cells. Neurons transmit nerve
messages. Glial cells are in direct contact with neurons and often surround
them. The neuron is the
functional unit of the nervous system. Humans have about 100 billion neurons
in their brain alone! While variable in size and shape, all neurons have
three parts. Dendrites receive information from another cell and transmit the
message to the cell body. The cell body contains the nucleus, mitochondria
and other organelles typical of eukaryotic cells. The axon conducts messages
away from the cell body. Three types of neurons
occur. Sensory neurons typically have a long dendrite and short axon, and
carry messages from sensory receptors to the central nervous system. Motor
neurons have a long axon and short dendrites and transmit messages from the
central nervous system to the muscles (or to glands). Interneurons are found
only in the central nervous system where they connect neuron to neuron. Some axons are wrapped in a
myelin sheath formed from the plasma membranes of specialized glial cells
known as Schwann cells. Schwann cells serve as supportive, nutritive, and
service facilities for neurons. The gap between Schwann cells is known as the
node of Ranvier, and serves as points along the neuron for generating a
signal. Signals jumping from node to node travel hundreds of times faster
than signals traveling along the surface of the axon. This allows your brain
to communicate with your toes in a few thousandths of a second. The Nerve Message
The plasma membrane of
neurons, like all other cells, has an unequal distribution of ions and
electrical charges between the two sides of the membrane. The outside of the membrane
has a positive charge, inside has a negative charge. This charge difference
is a resting potential and is measured in millivolts. Passage of ions across
the cell membrane passes the electrical charge along the cell. The voltage
potential is -65mV (millivolts) of a cell at rest (resting potential).
Resting potential results from differences between sodium and potassium
positively charged ions and negatively charged ions in the cytoplasm. Sodium
ions are more concentrated outside the membrane, while potassium ions are
more concentrated inside the membrane. This imbalance is maintained by the
active transport of ions to reset the membrane known as the sodium potassium
pump. The sodium-potassium pump maintains this unequal concentration by
actively transporting ions against their concentration gradients. Changed polarity of the
membrane, the action potential, results in propagation of the nerve impulse
along the membrane. An action potential is a temporary reversal of the
electrical potential along the membrane for a few milliseconds. Sodium gates
and potassium gates open in the membrane to allow their respective ions to
cross. Sodium and potassium ions reverse positions by passing through
membrane protein channel gates that can be opened or closed to control ion
passage. Sodium crosses first. At the height of the membrane potential
reversal, potassium channels open to allow potassium ions to pass to the
outside of the membrane. Potassium crosses second, resulting in changed ionic
distributions, which must be reset by the continuously running
sodium-potassium pump. Eventually enough potassium ions pass to the outside
to restore the membrane charges to those of the original resting potential.
The cell begins then to pump the ions back to their original sides of the
membrane. The action potential begins
at one spot on the membrane, but spreads to adjacent areas of the membrane,
propagating the message along the length of the cell membrane. After passage
of the action potential, there is a brief period, the refractory period,
during which the membrane cannot be stimulated. This prevents the message
from being transmitted backward along the membrane. Steps
in an Action Potential
Synapses
The junction between a
nerve cell and another cell is called a synapse. Messages travel within the
neuron as an electrical action potential. The space between two cells is
known as the synaptic cleft. To cross the synaptic cleft requires the actions
of neurotransmitters. Neurotransmitters are stored in small synaptic
vessicles clustered at the tip of the axon. Neurotransmitters tend to
be small molecules, some are even hormones. The time for neurotransmitter
action is between 0,5 and 1 millisecond. Neurotransmitters are either
destroyed by specific enzymes in the synaptic cleft, diffuse out of the
cleft, or are reabsorbed by the cell. More than 30 organic molecules are
thought to act as neurotransmitters. The neurotransmitters cross the cleft,
binding to receptor molecules on the next cell, prompting transmission of the
message along that cell's membrane. Acetylcholine is an example of a
neurotransmitter, as is norepinephrine, although each acts in different
responses. Diseases that affect the
function of signal transmission can have serious consequences. Parkinson's
disease has a deficiency of the neurotransmitter dopamine. Progressive death
of brain cells increases this deficit, causing tremors, rigidity and unstable
posture. L-dopa is a chemical related to dopamine that eases some of the
symptoms (by acting as a substitute neurotransmitter) but cannot reverse the
progression of the disease. Peripheral Nervous System
The Peripheral Nervous
System (PNS) contains only nerves and connects the brain and spinal cord
(CNS) to the rest of the body. The axons and dendrites are surrounded by a white
myelin sheath. Cell bodies are in the central nervous system (CNS) or
ganglia. Ganglia are collections of nerve cell bodies. Cranial nerves in the
PNS take impulses to and from the brain (CNS). Spinal nerves take impulses to
and away from the spinal cord. There are two major subdivisions of the PNS
motor pathways: the somatic and the autonomic. Two main components of the
PNS:
Most sensory input carried
in the PNS remains below the level of conscious awareness. Input that does
reach the conscious level contributes to perception of our external
environment. Somatic Nervous System
The Somatic Nervous System
(SNS) includes all nerves controlling the muscular system and external
sensory receptors. External sense organs (including skin) are receptors.
Muscle fibers and gland cells are effectors. The reflex arc is an automatic,
involuntary reaction to a stimulus. When the doctor taps your knee with the
rubber hammer, she/he is testing your reflex (or knee-jerk). The reaction to
the stimulus is involuntary, with the CNS being informed but not consciously
controlling the response. Examples of reflex arcs include balance, the
blinking reflex, and the stretch reflex. Sensory input from the PNS
is processed by the CNS and responses are sent by the PNS from the CNS to the
organs of the body. Motor neurons of the
somatic system are distinct from those of the autonomic system. Inhibitory
signals, cannot be sent through the motor neurons of the somatic system. Autonomic Nervous System
The Autonomic Nervous
System is that part of PNS consisting of motor neurons that control internal
organs. It has two subsystems. The autonomic system controls muscles in the
heart, the smooth muscle in internal organs such as the intestine, bladder,
and uterus. The Sympathetic Nervous System is involved in the fight or flight
response. The Parasympathetic Nervous System is involved in relaxation. Each
of these subsystems operates in the reverse of the other (antagonism). Both
systems innervate the same organs and act in opposition to maintain
homeostasis. For example: when you are scared the sympathetic system causes
your heart to beat faster; the parasympathetic system reverses this effect. Motor neurons in this
system do not reach their targets directly (as do those in the somatic
system) but rather connect to a secondary motor neuron which in turn
innervates the target organ. Central Nervous System
The Central Nervous System
(CNS) is composed of the brain and spinal cord. The CNS is surrounded by
bone-skull and vertebrae. Fluid and tissue also insulate the brain and spinal
cord. The brain is composed of
three parts: the cerebrum (seat of consciousness), the cerebellum, and the
medulla oblongata (these latter two are "part of the unconscious
brain"). The medulla oblongata is
closest to the spinal cord, and is involved with the regulation of heartbeat,
breathing, vasoconstriction (blood pressure), and reflex centers for
vomiting, coughing, sneezing, swallowing, and hiccupping. The hypothalamus
regulates homeostasis. It has regulatory areas for thirst, hunger, body
temperature, water balance, and blood pressure, and links the Nervous System
to the Endocrine System. The midbrain and pons are also part of the
unconscious brain. The thalamus serves as a central relay point for incoming
nervous messages. The cerebellum is the
second largest part of the brain, after the cerebrum. It functions for muscle
coordination and maintains normal muscle tone and posture. The cerebellum
coordinates balance. The conscious brain
includes the cerebral hemispheres, which are are separated by the corpus
callosum. In reptiles, birds, and mammals, the cerebrum coordinates sensory
data and motor functions. The cerebrum governs intelligence and reasoning,
learning and memory. While the cause of memory is not yet definitely known,
studies on slugs indicate learning is accompanied by a synapse decrease.
Within the cell, learning involves change in gene regulation and increased
ability to secrete transmitters. The
Brain:
During embryonic
development, the brain first forms as a tube, the anterior end of which enlarges
into three hollow swellings that form the brain, and the posterior of which
develops into the spinal cord. Some parts of the brain have changed little
during vertebrate evolutionary history. Vertebrate evolutionary
trends include
The Brain
Stem and Midbrain
The brain stem is the
smallest and from an evolutionary viewpoint, the oldest and most primitive
part of the brain. The brain stem is continuous with the spinal cord, and is
composed of the parts of the hindbrain and midbrain. The medulla oblongata
and pons control heart rate, constriction of blood vessels, digestion and
respiration. The midbrain consists of
connections between the hindbrain and forebrain. Mammals use this part of the
brain only for eye reflexes. The
Cerebellum
The cerebellum is the third
part of the hindbrain, but it is not considered part of the brain stem.
Functions of the cerebellum include fine motor coordination and body
movement, posture, and balance. This region of the brain is enlarged in birds
and controls muscle action needed for flight. The
Forebrain
The forebrain consists of
the diencephalon and cerebrum. The thalamus and hypothalamus are the parts of
the diencephalon. The thalamus acts as a switching center for nerve messages.
The hypothalamus is a major homeostatic center having both nervous and
endocrine functions. The cerebrum, the largest
part of the human brain, is divided into left and right hemispheres connected
to each other by the corpus callosum. The hemispheres are covered by a thin
layer of gray matter known as the cerebral cortex, the most recently evolved
region of the vertebrate brain. Fish have no cerebral cortex, amphibians and
reptiles have only rudiments of this area. The cortex in each
hemisphere of the cerebrum is between 1 and 4 mm thick. Folds divide the
cortex into four lobes: occipital, temporal, parietal, and frontal. No region
of the brain functions alone, although major functions of various parts of
the lobes have been determined. The occipital lobe (back of
the head) receives and processes visual information. The temporal lobe
receives auditory signals, processing language and the meaning of words. The
parietal lobe is associated with the sensory cortex and processes information
about touch, taste, pressure, pain, and heat and cold. The frontal lobe
conducts three functions:
Most people who have been
studied have their language and speech areas on the left hemisphere of their
brain. Language comprehension is found in Wernicke's area. Speaking ability
is in Broca's area. Damage to Broca's area causes speech impairment but not
impairment of language comprehension. Lesions in Wernicke's area impairs
ability to comprehend written and spoken words but not speech. The remaining
parts of the cortex are associated with higher thought processes, planning,
memory, personality and other human activities.
The
Spinal Cord:
The Spinal Cord
is connected to the brain and is about the diameter of a human finger. From
the brain the spinal cord descends down the middle of the back and is
surrounded and protected by the bony vertebral column. The spinal cord is
surrounded by a clear fluid called Cerebral Spinal Fluid (CSF), that acts as
a cushion to protect the delicate nerve tissues against damage from banging
against the inside of the vertebrae. The anatomy of
the spinal cord itself consists of millions of nerve fibers which transmit
electrical information to and from the limbs, trunk and organs of the body,
back to and from the brain. The brain and spinal cord are referred to as the
Central Nervous System, whilst the nerves connecting the spinal cord to the
body are referred to as the Peripheral Nervous System. The nerves
within the spinal cord are grouped together in different bundles called
Ascending and Descending tracts.
Nerves called
the spinal nerves or nerve roots come off the spinal cord and pass out
through a hole in each of the vertebrae called the Foramen to carry the
information from the spinal cord to the rest of the body, and from the body
back up to the brain There are four
main groups of spinal nerves which exit different levels of the spinal cord. These are in
descending order down the vertebral column:
The spinal
nerves carry information to and from different levels (segments) in the
spinal cord. Both the nerves and the segments in the spinal cord are numbered
in a similar way to the vertebrae. The point at which the spinal cord ends is
called the conus medullaris, and is the terminal end of the spinal cord. It
occurs near lumbar nerves L1 and L2. After the spinal cord terminates, the
spinal nerves continue as a bundle of nerves called the cauda equina. The
upper end of the conus medullaris is usually not well defined. There are 31
pairs of spinal nerves which branch off from the spinal cord. In the cervical
region of the spinal cord, the spinal nerves exit above the vertebrae. A
change occurs with the C7 vertebra however, where the C8 spinal nerve exits
the vertebra below the C7 vertebra. Therefore, there is an 8th cervical
spinal nerve even though there is no 8th cervical vertebra. From the 1st
thoracic vertebra downwards, all spinal nerves exit below their equivalent
numbered vertebrae. The spinal
nerves which leave the spinal cord are numbered according to the vertebra at
which they exit the spinal column. So, the spinal nerve T4, exits the spinal
column through the foramen in the 4th thoracic vertebra. The spinal nerve L5
leaves the spinal cord from the conus medullaris, and travels along the cauda
equina until it exits the 5th lumbar vertebra.
Source: http://mail.med.upenn.edu/~hessd/Lesson3.htm Drugs and the Brain
Some neurotransmitters are
excitory, such as acetylcholine, norepinephrine, serotonin, and dopamine.
Some are associated with relaxation, such as dopamine and serotonin. Dopamine
release seems related to sensations of pleasure. Endorphins are natural
opioids that produce elation and reduction of pain, as do artificial
chemicals such as opium and heroin. Neurological diseases, for example
Parkinson's disease and Huntington's disease, are due to imbalances of
neurotransmitters. Parkinson's is due to a dopamine deficiency. Huntington's
disease is thought to be cause by malfunctioning of an inhibitory neurotransmitter.
Alzheimer's disease is associated with protein plaques in the brain. Senses:
Input to the nervous system
is in the form of our five senses: pain, vision, taste, smell, and hearing.
Vision, taste, smell, and hearing input are the special senses. Pain,
temperature, and pressure are known as somatic senses. Sensory input begins
with sensors that react to stimuli in the form of energy that is transmitted
into an action potential and sent to the CNS. Sensory
Receptors
Orientation
and Gravity
Orientation
and gravity are detected at the semicircular canals. Hair cells along three
planes respond to shifts of liquid within the cochlea, providing a
three-dimensional sense of equilibrium. Calcium carbonate crystals can shift
in response to gravity, providing sensory information about gravity and
acceleration
Hearing
Hearing involves the
actions of the external ear, eardrum, ossicles, and cochlea. In hearing,
sound waves in air are converted into vibrations of a liquid then into
movement of hair cells in the cochlea. Finally they are converted into action
potentials in a sensory dendrite connected to the auditory nerve. Very loud
sounds can cause violent vibrations in the membrane under hair cells, causing
a shearing or permanent distortion to the cells, resulting in permanent
hearing loss. Eye
In the eye, two types of
photoreceptor cells are clustered on the retina, or back portion of the eye.
These receptors, rods and cones, apparently evolved from hair cells. Rods
detect differences in light intensity; cones detect color. Rods are more common
in a circular zone near the edge of the eye. Cones occur in the center (or
fovea centralis) of the retina. Light reaching a
photoreceptor causes the breakdown of the chemical rhodopsin, which in turn
causes a membrane potential that is transmitted to an action potential. The
action potential transfers to synapsed neurons that connect to the optic
nerve. The optic nerve connects to the occipital lobe of the brain. Photoreceptors
Detect Vision and Light Sensitivity:
Humans have three types of
cones, each sensitive to a different color of light: red, blue and green.
Opsins are chemicals that bind to cone cells and make those cells sensitive
to light of a particular wavelength (or color). Humans have three different
form of opsins coded for by three genes on the X chromosome. Defects in one
or more of these opsin genes can cause color blindness, usually in males. The
human eye can detect light in the 400-700 nanometer (nm) range, a small
portion of the electromagnetic spectrum, the visible light spectrum. Light
with wavelengths shorter than 400 nm is termed ultraviolet (UV) light. Light
with wavelengths longer than 700 nm is termed infrared (IR) light. |
Temperatures vary across both oceans, the Atlantic
ocean is warmer on average, sometimes by as much as 16 degrees
Fahrenheit at a given latitude. This is due to a number of factors, such as it being shallower, smaller and narrower than the Pacific ocean. The Pacific ocean covers 35 percent of the Earth’s surface, and the Atlantic covers only 21 percent. The Pacific ocean is the largest ocean and is almost as large as half of the other oceans combined. It also has the deepest average depth and the point of the lowest elevation on Earth. The second largest of the world’s oceans was actually named after the Greek Titan Atlas. The Atlantic Ocean was known as Ethiopian Ocean until the 19th century. The North Atlantic, where waters sink after being chilled by arctic temperatures, is the start of the “global ocean conveyor,” a circulation pattern that helps regulate Earth’s climate. The Atlantic Ocean covers approximately 20% of Earth's surface and at its deepest point it is about 8400 meters in the Puerto Rico Trench, which is located on the boundary between the Caribbean Sea and the Atlantic Ocean. The oceanic trench is the deepest point in the Atlantic Ocean. The Atlantic ocean receives more fresh water through run-offs than any other ocean. The Amazon, Mississippi, Saint Lawrence and Congo all empty into it. |
Nova
Dr. Neil deGrasse Tyson PhD |
You can't have a perpetual motion device, no matter how efficient,
it will always |
Stellar Parallax "Parsec" = 3.26 light years. |
Consider that our Sun is merely one
of "possibly" 200 Billion stars in the Milky Way Galaxy and if
that is not enough, there are several hundred billion Galaxies in the cosmos.
End-to-end, the Milky Way galaxy is 100,000 light years (about 30 kiloparsecs
in a flattened disk which is about 10,000 light years ( 3 kpc) thick at the
center. The sun is some 8.5 kiloparsecs out from the galactic center) across.
Traveling to the center of the galaxy, would take 27,000 years, at the speed
of light. On a scale, the milky way galaxy is not even a large one.
Approximately 6000 stars are visible with the naked eye. |
Our
nearest Star (other than our Sun) is just a Short Hop Should you wish to travel to our nearest star neighbor, which is 4.3 light years away ( beyond our Sun ), the journey will take you 300 years (a Light year is traveling at 186,280 miles per second, for one year) away, and you will be traveling at a speed of Ten (10) million miles per hour. Of course when you get within ten to twenty million miles from your destination, you will have already burned up. |
Moving rocks in the Desert: |
|
Earths Tectonic Plates:
Mid-Oceanic Ridges Geomagnetic
Anomalies
Deep Sea Trenches Island Arcs These observations, along
with many other studies of our planet, support the theory that underneath the
Earth's crust (the lithosphere: a solid array of plates) is a malleable layer
of heated rock known as the asthenosphere which is heated by radioactive
decay of elements such as Uranium, Thorium, and Potassium. Because the
radioactive source of heat is deep within the mantle, the fluid asthenosphere
circulates as convection currents underneath the solid lithosphere. This
heated layer is the source of lava we see in volcanoes, the source of heat
that drives hot springs and geysers, and the source of raw material which
pushes up the mid-oceanic ridges and forms new ocean floor. Magma continuously
wells upwards at the mid-oceanic ridges (arrows) producing currents of magma
flowing in opposite directions and thus generating the forces that pull the
sea floor apart at the mid-oceanic ridges. As the ocean floor is spread apart
cracks appear in the middle of the ridges allowing molten magma to surface
through the cracks to form the newest ocean floor. As the ocean floor moves
away from the mid-oceanic ridge it will eventually come into contact with a
continental plate and will be subducted underneath the continent. Finally,
the lithosphere will be driven back into the asthenosphere where it returns
to a heated state. Converging Boundary: In
other converging boundaries, there is no volcanic activity because the tectonic
plates are both continental plates, weighing the same. No subduction happens
along these margins, just massive deformation of the edges of the plates. The
Indian plate and the European plate are now creating the Himalayan Mountains,
these two plates have continued slamming into each other, causing the crust
to buckle, wrinkle, and uplift into the highest mountain range on earth. A
converging boundary is the opposite of a spreading boundary. Typically you
will see a converging boundary on a tectonic plate that is on the opposite
side of a spreading boundary. As a plate moves in one direction it collides
with the adjacent plate on its front, while the trailing end of the plate is
being pulled and stretched from the plate on the other end. The
Pacific plate is presently moving north and westward as the top edge
converges with the North American and European plates. Spreading Boundary: A spreading boundary is where the tectonic
plates are separating. Some spreading boundaries are places where the crust
is sinking downward as it is stretched thin. Many of the spreading boundaries
are located deep in the ocean on the sea floor. Here due to volcanic
activity, due to the crust is being torn open. New crust is forming when
molten lava from deep down slowly flows out of the cracks where the plates
are coming apart. Volcanic islands and the undersea mounts typically describe
these types of plate margins. Transverse Boundaries: Transverse
boundaries slide by on another. In many of these boundaries there is a lot of
tension and strain where the two plates are sliding and scraping past each
other. The resulting strain from the sliding action of the plates causes
cracks in the crust called faults. As the larger plates move past each other
some chunks of crust and overlying rock are broken into what are called fault
blocks. When there is a big enough movement along the cracks or faults in the
earth's crust this is the cause of earthquakes. The San Andreas fault in
California is a example of this. This fault is moving at a rate of
approximately 1.5 inches per year, the western boundary sliding northwest. Subduction: One plate, usually the lighter continental crust rides up on top
the other. Presently the South American plates are crashing into each other.
The lighter continental South American plate is riding up over the heavier
oceanic Nazca plate. Deep down where the leading edge of the Nazca plate is
diving down under the South American plate it's making contact with the
molten magma of the earth's mantle. This melts the Nazca plate margin sending
magma chambers rising to the surface where they sometimes break through in
volcanic eruptions. The subduction (downward) of the Nazca plate under the
South American continent is what caused the largest measurement in recorded
in1960 was a 9.5 earthquake. The Nazca plate continues to dive down below
the continent and it's this constant slow movement creates earthquakes
throughout that region. The Chilean earthquake of 1960 sent a tsunami 9,000
miles. Lithosphere: The asthenosphere's elastic
behaviour and low viscosity allow the overlying, more rigid plates of
lithosphere to move laterally in a process known as plate tectonics. Seismic
waves passing through this layer are significantly slowed. Isostatic
adjustments (the depression or uplift of continents by buoyancy) take place
in the asthenosphere, and magma is believed to be generated there. Its
elasticity and viscosity also allow overlying crust and mantle to move
vertically in response to gravity to achieve isostatic equilibrium |
QT: Some rare geysers erupt cold water, by the expelling of trapped cardon dioxide under-ground. |
PROPULSION |
Electromagnetic: A general derivation of the
thrust equation shows that the amount of thrust generated depends on the mass
flow through the engine and the exit velocity of the gas. Different
propulsion systems generate thrust in slightly different ways. If we think about Newton's
first law of motion, we realize that an airplane propulsion system must serve
two purposes. First, the thrust from the propulsion system must balance the
drag of the airplane when the airplane is cruising. And second, the thrust
from the propulsion system must exceed the drag of the airplane for the
airplane to accelerate. In fact, the greater the difference between the
thrust and the drag, called the excess thrust, the faster the airplane will
accelerate. Some aircraft, like
airliners and cargo planes, spend most of their life in a cruise condition.
For these airplanes, excess thrust is not as important as high engine
efficiency and low fuel usage. Since thrust depends on both the amount of gas
moved and the velocity, we can generate high thrust by accelerating a large
mass of gas by a small amount, or by accelerating a small mass of gas by a
large amount. Because of the aerodynamic efficiency of propellers and fans,
it is more fuel efficient to accelerate a large mass by a small amount. That
is why we find high bypass fans and turboprops on cargo planes and airliners. Some aircraft, like fighter
planes or experimental high speed aircraft, require very high excess thrust
to accelerate quickly and to overcome the high drag associated with high
speeds. For these airplanes, engine efficiency is not as important as very high
thrust. Modern military aircraft typically employ afterburners on a low
bypass turbofan core. Most likely, future hypersonic aircraft will employ
some type of ramjet or rocket propulsion. Laser Launch Systems: |
Although DNA is the carrier of genetic information in a cell, proteins do most of the work. Proteins are long chains containing as many as 20 different kinds of amino acids. Each cell contains thousands of different proteins: enzymes that make new molecules and catalyze nearly all chemical processes in cells; structural components that give cells their shape and help them move; hormones that transmit signals throughout the body; antibodies that recognize foreign molecules; and transport molecules that carry oxygen. The genetic code carried by DNA is what specifies the order and number of amino acids and, therefore, the shape and function of the protein. See DNA or RNA |
Pyroclastic
flows are high-density mixtures of hot, dry rock fragments and hot gases that
move away from the vent that erupted them at high speeds. They may result
from the explosive eruption of molten or solid rock fragments, or both. They
may also result from the nonexplosive eruption of lava when parts of dome or
a thick lava flow collapses down a steep slope. Most pyroclastic flows
consist of two parts: a basal flow of coarse fragments that moves along the
ground, and a turbulent cloud of ash that rises above the basal flow. Ash may
fall from this cloud over a wide area downwind from the pyroclastic flow. Scientists use a wide
variety of names to describe specific types of hot, dry flows of rock
fragments and gas produced by erupting volcanoes. The terms below are used to
describe either (1) the way in which a pyroclastic flow originates and moves;
or (2) a predominant characteristic of the resulting deposit. Ash Flow or Ash Cloud Block and Ash Flow Base Surge Directed Blast Nuée Ardente (glowing
cloud) Pumice Flow Pyroclastic Surge |
Quantum-Relativity Quantum Physics deals with the very small and Relativity pertains to the larger universe beyond. BillNye.com |
RADIOACTIVITY |
||||||||||||||||||||||||||||||||
Radioactive decay rates are
normally stated in terms of their half-lives**, and the half-life of a given
nuclear species is related to its radiation risk. The different types of
radioactivity lead to different decay paths which transmute the nuclei into
other chemical elements. Examining the amounts of the decay products makes
possible radioactive dating. **Half-lives
(t ½ ) can be VERY short (helium-5 decays in 7.6 x 10-22
seconds), or very long (thorium-232 decays in 1.4 billion years). The half-life is the amount of time that it will take half of
the atoms to decay. This does not mean that in twice that amount of
time, all the atoms will decay. Since this is a random process, there
is no history and you have to start over, so in the second half-life, half of
the remaining atoms will decay, leaving a quarter of the original atoms. Note: All the atoms
will still be there, but the ones that have decayed will be a different
element. Radiation from nuclear sources
is distributed equally in all directions, obeying the inverse square law. When an
unstable nucleus decays, there are three ways that it can do so. This means that they have a
charge of +2, and a mass of 4 Alpha particles are
relatively slow and heavy. They have a low penetrating
power - you can stop them with just a sheet of paper. Because
they have a large charge, alpha particles ionize other atoms strongly. Beta particles have a charge of minus
1, and a mass of about 1/2000th of a proton.
This means that beta particles are the same as an electron. They are fast, and light. Beta particles have a
medium penetrating power - they are stopped by a sheet of aluminum or
plastics such as perspex. Beta particles ionize atoms
that they pass, but not as strongly as Alpha particles do. Gamma
rays are
waves, not particles. This means that they have no mass and no
charge. Gamma rays have a high
penetrating power - it takes a thick sheet of metal such as lead, or concrete
to reduce them significantly. Gamma rays do not directly ionize
other atoms, although they may cause atoms to emit other particles which will
then cause ionisation. We don't find pure gamma
sources - gamma rays are emitted alongside alpha or beta particles. Strictly
speaking, gamma emission isn't 'radioactive decay' because it doesn't change
the state of the nucleus; it just carries away some energy. Types of Radioactivity
Just because something is
called an isotope doesn't necessarily mean it's radioactive. Consider a carbon atom. It
has 6 protons and 6 neutrons - we call it "carbon-12" because it
has an atomic mass of 12 (6 plus 6). Isotopes of an atom have
the same number of protons, but a different number of neutrons.
Deuterium-Tritium Fusion
Hydrogen Fusion Reactions
Even though a lot of energy
is required to overcome the Coulomb barrier and initiate hydrogen fusion, the
energy yields are enough to encourage continued research. Hydrogen fusion on
the earth could make use of the reactions: These reactions are more
promising than the proton-proton fusion of the stars for potential energy
sources. Of these the deuterium-tritium fusion appears to be the most
promising and has been the subject of most experiments. In a
deuterium-deuterium reactor, another reaction could also occur, creating a
deuterium cycle: Tritium Breeding
Deuterium-Tritium fusion is
the most promising of the hydrogen fusion reactions, but no tritium occurs in
nature since it has a 10 year half-life. The most promising source of tritium
seems to be the breeding of tritium from lithium-6 by neutron bombardment
with the reaction which can be achieved by slow neutrons. This would occur if
lithium were used as the coolant and heat transfer medium around the reaction
chamber of a fusion reactor. Lithium-6 makes up 7.4% of natural lithium.
While this constitutes a sizable supply, it is the limiting resource for the
D-T process since the supply of deuterium fuel is virtually unlimited. With
fast neutrons, tritium can be bred from the more abundant Li-7: Deuterium Source
Since the most practical
nuclear fusion reaction for power generation seems to be the
deuterium-tritium reaction, the sources of these fuels are important. The
deuterium part of the fuel does not pose a great problem because about 1 part
in 5000 of the hydrogen in seawater is deuterium. This amounts to over 10^15
tons of deuterium. Viewed as a potential fuel for a fusion reactor, a gallon
of seawater could produce as much energy as 300 gallons of gasoline. The
tritium part of the fuel is more problematic - there is no sizable natural
source since tritium is radioactive with a half-life of about 10 years. It
would have to be obtained by breeding the tritium from lithium. Nuclear Fission
Fission only
happens with heavy elements. The simplest
type of fission is called alpha-decay. A group of two protons and two
neutrons (called an “alpha particle”, which is basically a helium nucleus)
splits off and the rest of the nucleus remain as a whole. Fission can
also result in the nucleus splitting into a bunch of fragments of varying
sizes. Fission is
sometimes called Spontaneous Fission to distinguish it from Induced Fission,
which is when you hit the nucleus with a projectile such as a neutron.
Induced fission is responsible for most of the reactions in nuclear power
plants and nuclear bombs. If a massive nucleus like
uranium-235 breaks apart (fissions), then there will be a net yield of energy
because the sum of the masses of the fragments will be less than the mass of
the uranium nucleus. If the mass of the fragments is equal to or greater than
that of iron at the peak of the binding energy curve, then the nuclear
particles will be more tightly bound than they were in the uranium nucleus,
and that decrease in mass comes off in the form of energy according to the
Einstein equation. For elements lighter than iron, fusion will yield energy. The fission of U-235 in
reactors is triggered by the absorption of a low energy neutron, often termed
a "slow neutron" or a "thermal neutron". Other
fissionable isotopes which can be induced to fission by slow neutrons are
plutonium-239, uranium-233, and thorium-232. Nuclear Fusion
If light nuclei are forced
together, they will fuse with a yield of energy because the mass of the
combination will be less than the sum of the masses of the individual nuclei.
If the combined nuclear mass is less than that of iron at the peak of the
binding energy curve, then the nuclear particles will be more tightly bound
than they were in the lighter nuclei, and that decrease in mass comes off in
the form of energy according to the Einstein relationship. For elements
heavier than iron, fission will yield energy. For potential nuclear
energy sources for the Earth, the deuterium-tritium fusion reaction contained
by some kind of magnetic confinement seems the most likely path. However, for
the fueling of the stars, other fusion reactions will dominate. Light Water Reactors
The nuclear fission
reactors used in the United States for electric power production are classified
as "light water reactors" in contrast to the "heavy water
reactors" used in Canada. Light water (ordinary water) is used as
the moderator in U.S. reactors as well as the cooling agent and the means by
which heat is removed to produce steam for turning the turbines of the
electric generators. The use of ordinary water makes it necessary to do a
certain amount of enrichment of the uranium fuel before the necessary
criticality of the reactor can be maintained. The two varieties of the light
water reactor are the pressurized water reactor (PWR) and boiling water
reactor (BWR). Fusion Reactors
Reactors for nuclear
fusion are of two main varieties, magnetic confinement reactors and inertial
confinement reactors.
The strategies for creating fusion reactors are largely dictated by the fact
that the temperatures involved in nuclear fusion are far too high to be
contained in any material container. The strategy of the
magnetic confinement reactor is to confine the hot plasma by means of
magnetic fields which keep it perpetually in looping paths which do not touch
the wall of the container. This is typified by the tokamak design, the most
famous example of which is the TFTR at Princeton. The strategy of the
inertial confinement reactor is to put such high energy density into a small
pellet of deuterium-tritium that it fuses in such a short time that it can't
move appreciably. The most advanced test reactors involve laser fusion,
particularly in the Shiva and Nova reactors at Lawrence Livermore
Laboratories. Fast Breeder Reactors
Under appropriate operating
conditions, the neutrons given off by fission reactions can "breed"
more fuel from otherwise non-fissionable isotopes. The most common breeding
reaction is that of plutonium-239 from non-fissionable uranium-238. The term
"fast breeder" refers to the types of configurations which can
actually produce more fissionable fuel than they use, such as the LMFBR. This
scenario is possible because the non-fissionable uranium-238 is 140 times
more abundant than the fissionable U-235 and can be efficiently converted
into Pu-239 by the neutrons from a fission chain reaction. France has made the largest
implementation of breeder reactors ( it halted electricity production in 1996
and was closed as a commercial plant in 1997) with its large Super-Phenix
reactor and an intermediate scale reactor (BN-600) on the Caspian Sea for
electric power and desalinization.
A
Absolute risk: the proportion of a population
expected to get a disease over a specified time period. Absorbed dose: the amount of energy deposited by
ionizing radiation in a unit mass of tissue. It is expressed in units of
joule per kilogram (J/kg), and called “gray” (Gy). Activity (radioactivity): the rate of decay of radioactive
material expressed as the number of atoms breaking down per second measured
in units called becquerels or curies. Acute exposure: an exposure to radiation that
occurred in a matter of minutes rather than in longer, continuing exposure
over a period of time. Acute Radiation
Syndrome (ARS):
a serious illness caused by receiving a dose greater than 75 rads of
penetrating radiation to the body in a short time (usually minutes). The
earliest symptoms are nausea, fatigue, vomiting, and diarrhea. Hair loss,
bleeding, swelling of the mouth and throat, and general loss of energy may
follow. If the exposure has been approximately 1,000 rads or more, death may
occur within 2 – 4 weeks. Air burst: a nuclear weapon explosion that is
high enough in the air to keep the fireball from touching the ground. Because
the fireball does not reach the ground and does not pick up any surface
material, the radioactivity in the fallout from an air burst is relatively
insignificant compared with a surface burst. Alpha particle: the nucleus of a helium atom, made
up of two neutrons and two protons with a charge of +2. Certain radioactive
nuclei emit alpha particles. Alpha particles generally carry more energy than
gamma or beta particles, and deposit that energy very quickly while passing
through tissue. Alpha particles can be stopped by a thin layer of light
material, such as a sheet of paper, and cannot penetrate the outer, dead
layer of skin. Therefore, they do not damage living tissue when outside the
body. When alpha-emitting atoms are inhaled or swallowed, however, they are
especially damaging because they transfer relatively large amounts of
ionizing energy to living cells. Ambient air: the air that surrounds us. Americium (Am): a silvery metal; it is a man-made
element whose isotopes Am-237 through Am-246 are all radioactive. Am-241 is
formed spontaneously by the beta decay of plutonium-241. Trace quantities of
americium are widely used in smoke detectors, and as neutron sources in neutron
moisture gauges. Atom: the smallest particle of an element
that can enter into a chemical reaction. Atomic number: the total number of protons in the
nucleus of an atom. Atomic mass unit
(amu): 1 amu
is equal to one twelfth of the mass of a carbon-12 atom. Atomic mass number: the total number of protons and
neutrons in the nucleus of an atom. Atomic weight: the mass of an atom, expressed in
atomic mass units. For example, the atomic number of helium-4 is 2, the
atomic mass is 4, and the atomic weight is 4.00026. B
Background
radiation:
ionizing radiation from natural sources, such as terrestrial radiation due to
radionuclides in the soil or cosmic radiation originating in outer space. Becquerel (Bq): the amount of a radioactive material
that will undergo one decay (disintegration) per second. Beta particles: electrons ejected from the nucleus
of a decaying atom. Although they can be stopped by a thin sheet of aluminum,
beta particles can penetrate the dead skin layer, potentially causing burns.
They can pose a serious direct or external radiation threat and can be lethal
depending on the amount received. They also pose a serious internal radiation
threat if beta-emitting atoms are ingested or inhaled. Bioassay: an assessment of radioactive
materials that may be present inside a person’s body through analysis of the
person’s blood, urine, feces, or sweat. Biological Effects
of Ionizing Radiation (BEIR) Reports: reports of the National Research Council's committee
on the Biological Effects of Ionizing Radiation. Biological
half-life: the
time required for one half of the amount of a substance, such as a
radionuclide, to be expelled from the body by natural metabolic processes,
not counting radioactive decay, once it has been taken in through inhalation,
ingestion, or absorption. . C
Carcinogen: a cancer-causing substance. Chain reaction: a process that initiates its own
repetition. In a fission chain reaction, a fissile nucleus absorbs a neutron
and fissions (splits) spontaneously, releasing additional neutrons. These, in
turn, can be absorbed by other fissile nuclei, releasing still more neutrons.
A fission chain reaction is self-sustaining when the number of neutrons
released in a given time equals or exceeds the number of neutrons lost by
absorption in non-fissile material or by escape from the system. Chronic exposure: exposure to a substance over a long
period of time, possibly resulting in adverse health effects. Cobalt (Co): gray, hard, magnetic, and somewhat
malleable metal. Cobalt is relatively rare and generally obtained as a
byproduct of other metals, such as copper. Its most common radioisotope,
cobalt-60 (Co-60), is used in radiography and medical applications. Cobalt-60
emits beta particles and gamma rays during radioactive decay. Collective dose: the estimated dose for an area or
region multiplied by the estimated population in that area or region. Committed dose: a dose that accounts for continuing
exposures expected to be received over a long period of time (such as 30, 50,
or 70 years) from radioactive materials that were deposited inside the body. Concentration: the ratio of the amount of a
specific substance in a given volume or mass of solution to the mass or
volume of solvent. Contamination
(radioactive):
the deposition of unwanted radioactive material on the surfaces of
structures, areas, objects, or people where it may be external or
internal. Cosmic radiation: radiation produced in outer space
when heavy particles from other galaxies (nuclei of all known natural
elements) bombard the earth. Criticality: a fission process where the neutron
production rate equals the neutron loss rate to absorption or leakage. A
nuclear reactor is "critical" when it is operating. Critical mass: the minimum amount of fissile material
that can achieve a self-sustaining nuclear chain reaction. Cumulative dose: the total dose resulting from
repeated or continuous exposures of the same portion of the body, or of the
whole body, to ionizing radiation. Curie (Ci): the traditional measure of
radioactivity based on the observed decay rate of 1 gram of radium. One curie
of radioactive material will have 37 billion disintegrations in 1 second. Cutaneous Radiation
Syndrome (CRS):
the complex syndrome resulting from radiation exposure of more than 200 rads
to the skin. The immediate effects can be reddening and swelling of the
exposed area (like a severe burn), blisters, ulcers on the skin, hair loss,
and severe pain. Very large doses can result in permanent hair loss,
scarring, altered skin color, deterioration of the affected body part, and
death of the affected tissue (requiring surgery). D
Decay chain (decay
series): the
series of decays that certain radioisotopes go through before reaching a stable
form. For example, the decay chain that begins with uranium-238 (U-238) ends
in lead-206 (Pb-206), after forming isotopes, such as uranium-234 (U-234),
thorium-230 (Th-230), radium-226 (Ra-226), and radon-222 (Rn-222). Decay constant: the fraction of a number of atoms
of a radioactive nuclide that disintegrates in a unit of time. The decay
constant is inversely proportional to the radioactive half-life. Decay products (or
daughter products):
the isotopes or elements formed and the particles and high-energy
electromagnetic radiation emitted by the nuclei of radionuclides during
radioactive decay. Also known as "decay chain products" or
"progeny" (the isotopes and elements). A decay product may be
either radioactive or stable. Decontamination: the reduction or removal of
radioactive contamination from a structure, object, or person. Depleted uranium: uranium containing less than 0.7%
uranium-235, the amount found in natural uranium. . Deposition density: the activity of a radionuclide per
unit area of ground. Reported as becquerels per square meter or curies per
square meter. Deterministic
effects: effects
that can be related directly to the radiation dose received. The severity
increases as the dose increases. A deterministic effect typically has a
threshold below which the effect will not occur. See also stochastic effect, non-stochastic
effect. Deuterium: a non-radioactive isotope of the
hydrogen atom that contains a neutron in its nucleus in addition to the one
proton normally seen in hydrogen. A deuterium atom is twice as heavy as
normal hydrogen. See also
tritium. Dirty bomb: a device designed to spread
radioactive material by conventional explosives when the bomb explodes. A
dirty bomb kills or injures people through the initial blast of the
conventional explosive and spreads radioactive contamination over possibly a
large area—hence the term “dirty.” Such bombs could be miniature devices or
large truck bombs. A dirty bomb is much simpler to make than a true nuclear
weapon. Dose (radiation): radiation absorbed by person’s
body. Several different terms describe radiation dose. For more information,
see “Primer on Radiation Measurement” at the end of this document. Dose coefficient: the factor used to convert
radionuclide intake to dose. Usually expressed as dose per unit intake (e.g.,
sieverts per becquerel). Dose equivalent: a quantity used in radiation
protection to place all radiation on a common scale for calculating tissue
damage. Dose equivalent is the absorbed dose in grays times the quality
factor. The quality factor accounts for differences in radiation effects
caused by different types of ionizing radiation. Some radiation, including
alpha particles, causes a greater amount of damage per unit of absorbed dose
than other radiation. The sievert (Sv) is the unit used to measure dose
equivalent. For more information, see “Primer on Radiation Measurement” at
the end of this document. Dose rate: the radiation dose delivered per
unit of time. Dose
reconstruction:
a scientific study that estimates doses to people from releases of
radioactivity or other pollutants. The dose is reconstructed by determining
the amount of material released, the way people came in contact with it, and
the amount they absorbed. Dosimeter: a small portable instrument (such
as a film badge, thermoluminescent dosimeter [TLD], or pocket dosimeter) for
measuring and recording the total accumulated dose of ionizing radiation a
person receives. Dosimetry: assessment (by measurement or
calculation) of radiation dose. E
Effective dose: a dosimetric quantity useful for
comparing the overall health affects of irradiation of the whole body. It
takes into account the absorbed doses received by various organs and tissues
and weighs them according to present knowledge of the sensitivity of each
organ to radiation. It also accounts for the type of radiation and the
potential for each type to inflict biologic damage. The effective dose is
used, for example, to compare the overall health detriments of different
radionuclides in a given mix. The unit of effective dose is the sievert (Sv);
1 Sv = 1 J/kg. Effective
half-life: the
time required for the amount of a radionuclide deposited in a living organism
to be diminished by 50% as a result of the combined action of radioactive
decay and biologic elimination. Electron: an elementary particle with a
negative electrical charge and a mass 1/1837 that of the proton. Electrons
surround the nucleus of an atom because of the attraction between their
negative charge and the positive charge of the nucleus. A stable atom will
have as many electrons as it has protons. The number of electrons that orbit an
atom determine its chemical properties. Element: 1) all isotopes of an atom that
contain the same number of protons. For example, the element uranium has 92
protons, and the different isotopes of this element may contain 134 to 148
neutrons. 2) In a reactor, a fuel element is a metal rod containing the
fissile material. Enriched uranium: uranium in which the proportion of
the isotope uranium-235 has been increased by removing uranium-238
mechanically. Exposure
(radiation): a
measure of ionization in air caused by x-rays or gamma rays only. The unit of
exposure most often used is the roentgen. Exposure pathway: a route by which a radionuclide or
other toxic material can enter the body. The main exposure routes are
inhalation, ingestion, absorption through the skin, and entry through a cut
or wound in the skin. Exposure rate: a measure of the ionization
produced in air by x-rays or gamma rays per unit of time (frequently
expressed in roentgens per hour). External exposure: exposure to radiation outside of the
body. F
Fallout, nuclear: minute particles of radioactive
debris that descend slowly from the atmosphere after a nuclear explosion. Fissile material: any material in which neutrons can
cause a fission reaction. The three primary fissile materials are uranium-233,
uranium-235, and plutonium-239. Fission
(fissioning):
the splitting of a nucleus into at least two other nuclei that releases a
large amount of energy. Two or three neutrons are usually released during
this transformation. See
also fusion. Fractionated
exposure:
exposure to radiation that occurs in several small acute exposures, rather
than continuously as in a chronic exposure. Fusion: a reaction in which at least one
heavier, more stable nucleus is produced from two lighter, less stable nuclei.
Reactions of this type are responsible for the release of energy in stars or
in thermonuclear weapons. G
Gamma rays: high-energy electromagnetic
radiation emitted by certain radionuclides when their nuclei transition from
a higher to a lower energy state. These rays have high energy and a short
wave length. All gamma rays emitted from a given isotope have the same
energy, a characteristic that enables scientists to identify which gamma
emitters are present in a sample. Gamma rays penetrate tissue farther than do
beta or alpha particles, but leave a lower concentration of ions in their
path to potentially cause cell damage. Gamma rays are very similar to
x-rays. Geiger counter: a radiation detection and measuring
instrument consisting of a gas-filled tube containing electrodes, between
which an electrical voltage but no current flows. When ionizing radiation
passes through the tube, a short, intense pulse of current passes from the
negative electrode to the positive electrode and is measured or counted. The
number of pulses per second measures the intensity of the radiation field.
Geiger counters are the most commonly used portable radiation detection
instruments. Genetic effects: hereditary effects (mutations) that
can be passed on through reproduction because of changes in sperm or
ova. Gray (Gy): a unit of measurement for absorbed
dose. It measures the amount of energy absorbed in a material. The unit Gy
can be used for any type of radiation, but it does not describe the
biological effects of the different radiations. Half-life: the time any substance takes to
decay by half of its original amount. High-level
radioactive waste:
the radioactive material resulting from spent nuclear fuel reprocessing. This
can include liquid waste directly produced in reprocessing or any solid
material derived from the liquid wastes having a sufficient concentration of
fission products. Other radioactive materials can be designated as high-level
waste, if they require permanent isolation. This determination is made by the
U.S. Nuclear Regulatory Commission on the basis of criteria established in
U.S. law. Hot spot: any place where the level of
radioactive contamination is considerably greater than the area around it. I
Ingestion: 1) the act of swallowing; 2) in the
case of radionuclides or chemicals, swallowing radionuclides or chemicals by
eating or drinking. Inhalation: 1) the act of breathing in; 2) in
the case of radionuclides or chemicals, breathing in radionuclides or chemicals. Internal exposure: exposure to radioactive material
taken into the body. Iodine: a nonmetallic solid element. There
are both radioactive and non-radioactive isotopes of iodine. Radioactive
isotopes of iodine are widely used in medical applications. Radioactive
iodine is a fission product and is the largest contributor to people’s
radiation dose after an accident at a nuclear reactor. Ion: an atom that has fewer or more
electrons than it has protons causing it to have an electrical charge and,
therefore, be chemically reactive. Ionization: the process of adding one or more
electrons to, or removing one or more electrons from, atoms or molecules,
thereby creating ions. High temperatures, electrical discharges, or nuclear
radiation can cause ionization.
Irradiation: exposure to radiation. Isotope: a nuclide of an element having the
same number of protons but a different number of neutrons. K
Kiloton (Kt): the energy of an explosion that is
equivalent to an explosion of 1,000 tons of TNT. One kiloton equals 1
trillion (1012) calories. See
also megaton. L
Latent period: the time between exposure to a
toxic material and the appearance of a resultant health effect. Lead (Pb): a heavy metal. Several isotopes of
lead, such as Pb-210 which emits beta radiation, are in the uranium decay
chain. Local radiation
injury (LRI):
acute radiation exposure (more than 1,000 rads) to a small, localized part of
the body. Most local radiation injuries do not cause death. However, if the
exposure is from penetrating radiation (neutrons, x-rays, or gamma rays),
internal organs may be damaged and some symptoms of acute radiation syndrome
(ARS), including death, may occur. Local radiation injury invariably involves
skin damage, and a skin graft or other surgery may be required. Low-level waste (LLW): radioactively contaminated
industrial or research waste such as paper, rags, plastic bags, medical
waste, and water-treatment residues. It is waste that does not meet the
criteria for any of three other categories of radioactive waste: spent
nuclear fuel and high-level radioactive waste; transuranic radioactive waste;
or uranium mill tailings. Its categorization does not depend on the level of
radioactivity it contains. M
Megaton (Mt): the energy of an explosion that is
equivalent to an explosion of 1 million tons of TNT. One megaton is equal to
a quintillion (1018) calories. See
also kiloton. Molecule: a combination of two or more atoms
that are chemically bonded. A molecule is the smallest unit of a compound
that can exist by itself and retain all of its chemical properties. N
Neoplastic: pertaining to the pathologic
process resulting in the formation and growth of an abnormal mass of tissue. Neutron: a small atomic particle possessing
no electrical charge typically found within an atom's nucleus. Neutrons are,
as the name implies, neutral in their charge. That is, they have neither a
positive nor a negative charge. A neutron has about the same mass as a
proton. See also
alpha particle, beta particle, gamma ray, nucleon, x-ray. Non-ionizing
radiation:
radiation that has lower energy levels and longer wavelengths than ionizing
radiation. It is not strong enough to affect the structure of atoms it
contacts but is strong enough to heat tissue and can cause harmful biological
effects. Examples include radio waves, microwaves, visible light, and
infrared from a heat lamp. Non-stochastic
effects:
effects that can be related directly to the radiation dose received. The
effect is more severe with a higher dose. It typically has a threshold, below
which the effect will not occur. These are sometimes called deterministic
effects. For example, a skin burn from radiation is a non-stochastic effect
that worsens as the radiation dose increases. See also stochastic effects. Nuclear energy: the heat energy produced by the
process of nuclear fission within a nuclear reactor or by radioactive decay. Nuclear fuel cycle: the steps involved in supplying
fuel for nuclear power plants. It can include mining, milling, isotopic
enrichment, fabrication of fuel elements, use in reactors, chemical
reprocessing to recover the fissile material remaining in the spent fuel,
reenrichment of the fuel material refabrication into new fuel elements, and
waste disposal. Nuclear tracers: radioisotopes that give doctors the
ability to "look" inside the body and observe soft tissues and
organs, in a manner similar to the way x-rays provide images of bones. A
radioactive tracer is chemically attached to a compound that will concentrate
naturally in an organ or tissue so that an image can be taken. Nucleon: a proton or a neutron; a
constituent of the nucleus of an atom. Nucleus: the central part of an atom that
contains protons and neutrons. The nucleus is the heaviest part of the atom. Nuclide: a general term applicable to all
atomic forms of an element. Nuclides are characterized by the number of
protons and neutrons in the nucleus, as well as by the amount of energy
contained within the atom. P
Pathways: the routes by which people are
exposed to radiation or other contaminants. The three basic pathways are
inhalation, ingestion, and direct external exposure. Penetrating
radiation:
radiation that can penetrate the skin and reach internal organs and tissues.
Photons (gamma rays and x-rays), neutrons, and protons are penetrating
radiations. However, alpha particles and all but extremely high-energy beta
particles are not considered penetrating radiation. Photon: discrete "packet" of pure
electromagnetic energy. Photons have no mass and travel at the speed of light.
The term "photon" was developed to describe energy when it acts
like a particle (causing interactions at the molecular or atomic level),
rather than a wave. Gamma rays and x-rays are photons. Pitchblende: a brown to black mineral that has a
distinctive luster. It consists mainly of urananite (UO2), but also contains
radium (Ra). It is the main source of uranium (U) ore. Plume: the material spreading from a
particular source and traveling through environmental media, such as air or
ground water. For example, a plume could describe the dispersal of particles,
gases, vapors, and aerosols in the atmosphere, or the movement of
contamination through an aquifer (For example, dilution, mixing, or
adsorption onto soil). Plutonium (Pu): a heavy, man-made, radioactive
metallic element. The most important isotope is Pu-239, which has a half-life
of 24,000 years. Pu-239 can be used in reactor fuel and is the primary
isotope in weapons. One kilogram is equivalent to about 22 million
kilowatt-hours of heat energy. The complete detonation of a kilogram of
plutonium produces an explosion equal to about 20,000 tons of chemical
explosive. All isotopes of plutonium are readily absorbed by the bones and
can be lethal depending on the dose and exposure time. Polonium (Po): a radioactive chemical element and
a product of radium (Ra) decay. Polonium is found in uranium (U) ores. Prenatal radiation
exposure:
radiation exposure to an embryo or fetus while it is still in its mother’s
womb. At certain stages of the pregnancy, the fetus is particularly sensitive
to radiation and the health consequences could be severe above 5 rads,
especially to brain function. Proton: a small atomic particle, typically
found within an atom's nucleus, that possesses a positive electrical charge.
Even though protons and neutrons are about 2,000 times heavier than
electrons, they are tiny. The number of protons is unique for each chemical
element. See also
nucleon. Q
Quality factor (Q): the factor by which the absorbed
dose (rad or gray) is multiplied to obtain a quantity that expresses, on a
common scale for all ionizing radiation, the biological damage (rem) to an
exposed person. It is used because some types of radiation, such as alpha
particles, are more biologically damaging internally than other types. R
Rad (radiation
absorbed dose):
a basic unit of absorbed radiation dose. It is a measure of the amount of
energy absorbed by the body. The rad is the traditional unit of absorbed
dose. It is being replaced by the unit gray (Gy), which is equivalent to 100
rad. One rad equals the dose delivered to an object of 100 ergs of energy per
gram of material. Radiation: energy moving in the form of
particles or waves. Familiar radiations are heat, light, radio waves, and
microwaves. Ionizing radiation is a very high-energy form of electromagnetic
radiation. Radiation sickness: See
also acute radiation syndrome (ARS), or the CDC fact sheet “Acute
Radiation Syndrome,” at emergency.cdc.gov/radiation/ars.asp. Radiation warning
symbol: a symbol
prescribed by the Code of Federal Regulations. It is a magenta or black
trefoil on a yellow background. It must be displayed where certain quantities
of radioactive materials are present or where certain doses of radiation
could be received. Radioactive
contamination:
the deposition of unwanted radioactive material on the surfaces of
structures, areas, objects, or people. It can be airborne, external, or
internal. Radioactive decay: the spontaneous disintegration of
the nucleus of an atom. Radioactive
half-life: the
time required for a quantity of a radioisotope to decay by half. For example,
because the half-life of iodine-131 (I-131) is 8 days, a sample of I-131 that
has 10 mCi of activity on January 1, will have 5 mCi of activity 8 days
later, on January 9. Radioactive
material:
material that contains unstable (radioactive) atoms that give off radiation
as they decay. Radioactivity: the process of spontaneous
transformation of the nucleus, generally with the emission of alpha or beta
particles often accompanied by gamma rays. This process is referred to as
decay or disintegration of an atom. Radioassay: a test to determine the amounts of
radioactive materials through the detection of ionizing radiation.
Radioassays will detect transuranic nuclides, uranium, fission and activation
products, naturally occurring radioactive material, and medical isotopes. Radiogenic: health effects caused by exposure
to ionizing radiation. Radiography: 1) medical: the use of radiant energy (such as
x-rays and gamma rays) to image body systems. 2) industrial: the use of radioactive sources
to photograph internal structures, such as turbine blades in jet engines. A
sealed radiation source, usually iridium-192 (Ir-192) or cobalt-60 (Co-60),
beams gamma rays at the object to be checked. Gamma rays passing through
flaws in the metal or incomplete welds strike special photographic film
(radiographic film) on the opposite side. Radioisotope
(radioactive isotope):
isotopes of an element that have an unstable nucleus. Radioactive isotopes
are commonly used in science, industry, and medicine. The nucleus eventually
reaches a stable number of protons and neutrons through one or more
radioactive decays. Approximately 3,700 natural and artificial radioisotopes
have been identified. Radiological or
radiologic: related
to radioactive materials or radiation. The radiological sciences focus on the
measurement and effects of radiation. Radiological
dispersal device (RDD):
a device that disperses radioactive material by conventional explosive or
other mechanical means, such as a spray. See
also dirty bomb. Radionuclide: an unstable and therefore
radioactive form of a nuclide. Radium (Ra): a naturally occurring radioactive
metal. Radium is a radionuclide formed by the decay of uranium (U) and
thorium (Th) in the environment. It occurs at low levels in virtually all
rock, soil, water, plants, and animals. Radon (Rn) is a decay product of
radium. Radon (Rn): a naturally occurring radioactive
gas found in soils, rock, and water throughout the United States. Radon
causes lung cancer and is a threat to health because it tends to collect in
homes, sometimes to very high concentrations. As a result, radon is the
largest source of exposure to people from naturally occurring radiation. Relative risk: the ratio between the risks for
disease in an irradiated population to the risk in an unexposed population. A
relative risk of 1.1 indicates a 10% increase in cancer from radiation,
compared with the "normal" incidence. Rem (roentgen
equivalent, man):
a unit of equivalent dose. Not all radiation has the same biological effect,
even for the same amount of absorbed dose. Rem relates the absorbed dose in
human tissue to the effective biological damage of the radiation. It is
determined by multiplying the number of rads by the quality factor, a number
reflecting the potential damage caused by the particular type of radiation.
The rem is the traditional unit of equivalent dose, but it is being replaced
by the sievert (Sv), which is equal to 100 rem. Roentgen
(R): a unit of
exposure to x-rays or gamma rays. One roentgen is the amount of gamma or
x-rays needed to produce ions carrying 1 electrostatic unit of electrical
charge in 1 cubic centimeter of dry air under standard conditions. S
Sensitivity: ability of an analytical method to
detect small concentrations of radioactive material. Shielding: the material between a radiation
source and a potentially exposed person that reduces exposure. Sievert (Sv): a unit used to derive a quantity
called dose equivalent. This relates the absorbed dose in human tissue to the
effective biological damage of the radiation. Not all radiation has the same
biological effect, even for the same amount of absorbed dose. Dose equivalent
is often expressed as millionths of a sievert, or micro-sieverts (µSv). One
sievert is equivalent to 100 rem. S.I. units: the Systeme Internationale (or
International System) of units and measurements. This system of units
officially came into being in October 1960 and has been adopted by nearly all
countries, although the amount of actual usage varies considerably. Somatic effects: effects of radiation that are
limited to the exposed person, as distinguished from genetic effects, which
may also affect subsequent generations. See
also teratogenic effects. Stable nucleus: the nucleus of an atom in which the
forces among its particles are balanced. See
also unstable nucleus. Stochastic effect: effect that occurs on a random
basis independent of the size of dose. The effect typically has no threshold
and is based on probabilities, with the chances of seeing the effect
increasing with dose. If it occurs, the severity of a stochastic effect is
independent of the dose received. Cancer is a stochastic effect. S Strontium (Sr): a silvery, soft metal that rapidly
turns yellow in air. Sr-90 is one of the radioactive fission materials
created within a nuclear reactor during its operation. Stronium-90 emits beta
particles during radioactive decay. Surface burst: a nuclear weapon explosion that is
close enough to the ground for the radius of the fireball to vaporize surface
material. Fallout from a surface burst contains very high levels of
radioactivity. T
Tailings: waste rock from mining operations
that contains concentrations of mineral ore that are too low to make typical
extraction methods economical. Thermonuclear
device: a
“hydrogen bomb.” A device with explosive energy that comes from fusion of
small nuclei, as well as fission. Teratogenic effect: birth defects that are not passed
on to future generations, caused by exposure to a toxin as a fetus. See also genetic
effects, somatic effects. Terrestrial
radiation:
radiation emitted by naturally occurring radioactive materials, such as
uranium (U), thorium (Th), and radon (Rn) in the earth. Thorium (Th): a naturally occurring radioactive
metal found in small amounts in soil, rocks, water, plants, and animals. The
most common isotopes of thorium are thorium-232 (Th-232), thorium-230
(Th-230), and thorium-238 (Th-238). Transuranic: pertaining to elements with atomic
numbers higher than uranium (92). For example, plutonium (Pu) and americium
(Am) are transuranics. Tritium: (chemical symbol H-3) a radioactive
isotope of the element hydrogen (chemical symbol H). U
Unstable nucleus: a nucleus that contains an uneven
number of protons and neutrons and seeks to reach equilibrium between them
through radioactive decay (i.e., the nucleus of a radioactive atom). See also stable nucleus. Uranium (U): a naturally occurring radioactive
element whose principal isotopes are uranium-238 (U-238) and uranium-235
(U-235). Natural uranium is a hard, silvery-white, shiny metallic ore that
contains a minute amount of uranium-234 (U-234). Uranium mill
tailings:
naturally radioactive residue from the processing of uranium ore. Although
the milling process recovers about 95% of the uranium, the residues, or
tailings, contain several isotopes of naturally occurring radioactive
material, including uranium (U), thorium (Th), radium (Ra), polonium (Po),
and radon (Rn). W
Whole body count: the measure and analysis of the
radiation being emitted from a person’s entire body, detected by a counter
external to the body. Whole body
exposure: an
exposure of the body to radiation, in which the entire body, rather than an
isolated part, is irradiated by an external source. X
X-ray: electromagnetic radiation caused by
deflection of electrons from their original paths, or inner orbital electrons
that change their orbital levels around the atomic nucleus. X-rays, like
gamma rays can travel long distances through air and most other materials.
Like gamma rays, x-rays require more shielding to reduce their intensity than
do beta or alpha particles. X-rays and gamma rays differ primarily in their
origin: x-rays originate in the electronic shell; gamma rays originate in the
nucleus. See also
neutron. |
"Dawn of History" Studies have shown that at the end of the Ice Age in 11,000 BC, global temperatures increased 5 degrees, and during the height of the last Ice age, the Oceans were 300 feet lower than today. |
|
LEAD ( Pb - 82) Is a Neurotoxin, too much in your system can cause irreparable damage to the brain and the central nervous system. It accumulates in the Bones and Blood. Levels measured in the US today; show that we have over 675 times more lead in our bodies than were present 100 years ago. |
WHO NEEDS THE SUN AND THE WATER ANYWAY ? |
Earthlings Do, they cannot exist without it. The
answer is that without the Sun, Earth's land, water, and air would all
be frozen solid! Life on Earth would cease to exist. That's because
almost all living things rely on the steady light and heat of the Sun.
The Sun's heat makes liquid water on our planet possible The sun
is the closest star to Earth. Even at a distance of 150 million
kilometers (93 million miles), its gravitational pull holds the planet
in orbit. It radiates light and heat, or solar energy, which makes it
possible for life to exist on Earth. The
sun, on the other hand, offers free and clean energy in abundance. In
fact, it gives much more energy than we can ever possibly use. Perhaps,
someday inhabitants of our earth will manage to take full advantage of
it. Without
water, there would be no clouds to provide a buffer from the heating
power of the sun. Without them the sun would pour down. Dry air would
suck out whatever moisture it could find, wherever it could find it,
and the noses and soft tissues of any being that lived would shrivel.
There would be no sweet scents, since smells are conveyed by moisture. The
composition of the air would change too. All the methane currently
stored in ice, bogs, and the ocean, would be released. That would
reduce the balance of oxygen in the air, and increase the heating
effect of the sun. The dust in the air would be blown hither and yon,
with nothing to wash it down. Temperatures would swing from extreme to
extreme, getting hotter as time went on. Water in the air feeds the earth, and water in the earth feeds the air. The
hydrologic cycle works as follows: From it's most usable state, water
evaporates and joins the air as water vapor. When the air cools, the
vapor condenses and creates clouds, which help block heat from the sun.
Colonies of the ice-nucleating bacterium blown into the clouds by wind,
help them to precipitate and fall as rain, snow, or hail. Much of the
precipitation is stored on land as groundwater. Water
is a life giver—even a life creator. It lies at the basis of our
understanding of how life works. It also lies at the basis of how we
understand our own personal lives. Of the four (or five) basic building
blocks of life, water is the only one with a visible cycle, which we
call the hydrologic cycle. Fire has no cycle that we can see, neither
do earth or air. And we don't understand spirit enough to know if it
does or not. Water is a constant reminder that life repeats. |
The
Moon:
According to present theory, It is
thought that the moon was once part of a planet that collided (It was not a
head-on collision, but rather a glancing blow. The impact imparts what
astronomers call angular momentum into the system. It sets Earth to spinning
(although, the Earth could have already been spinning) on its axis and
creates a Moon that would go round and round the host planet for billions of
years, at least until it flies away, due to loss of gravity from Earth) with
the forming earth, yet interestingly, if the Moon was carved out of the
Earths growth phase ( the moon is thought to have been pieced together by the
bits that got blown off the upper layers of Earth, as well as the outer
portions of the object that hit Earth), then it would have been around
when Earth continued swallowing vast numbers of large asteroids. Some of
these iron rich rocks would have hit the Moon, too, yet the iron is not on
the moon? |
Sonoluminescence |
It
occurs when a small gas bubble is acoustically suspended and
periodically driven in a liquid solution at ultrasonic frequencies,
resulting in bubble collapse, cavitation, and light emission. The
thermal energy that is released from the bubble collapse is so great
that it can cause weak light emission. The mechanism
of the light emission remains uncertain, but some of the current
theories, which are categorized under either thermal or electrical
processes, are Bremsstrahlung radiation, argon rectification
hypothesis, and hot spot. Some researchers are beginning to favor
thermal process explanations as temperature differences have
consistently been observed with different methods of spectral analysis
In order to understand the light emission mechanism, it is important to
know what is happening in the bubble's interior and at the bubble's
surface. |
|
TSUNAMI " Tsu\harbor nami/wave"
(the “T” is silent) |
It usually takes an
earthquake greater than 7.5 on the Richter scale to produce dangerous
tsunami. Sometimes people use the
words tidal wave
and tsunami
to mean the same thing. However, the two are not related. While tsunami
refers to dangerous waves caused by underwater disturbances, tidal waves are
simply the crest of tides as they travel around the Earth. Tsunamis
have nothing to do with tides. A series of
waves created when a body of water, such as an ocean, is rapidly displaced.
Earthquakes (Tsunamis may be generated when an earthquake occurs causing the
floor of the ocean to vertically displace the water column - one part
"rises" while the other part "sinks"), mass movements above or below water, some volcanic eruptions and other underwater explosions, landslides and underwater earthquake at sea all have
the potential to generate a tsunami. The effects of a tsunami are always
devastating due to the immense volumes of water and energy involved. Since meteorites are small, they will not generate a
tsunami, conversely, should an asteroid hit the oceans, the subsequent wave
would be of extreme devastation. A Tsunami looks like an
endlessly onrushing tide which forces its way around and through any
obstacle. Most of the damage is caused by the huge mass of water behind the
initial wave front, as the height of the sea keeps rising fast and floods
powerfully into the coastal area. The sheer weight of water is enough to
pulverize objects in its path, often reducing buildings to their foundations
and scouring exposed ground to the bedrock. Large objects such as ships and
boulders can be carried several miles inland before the tsunami subsides. Tsunamis act very
differently from typical surf swells; they are phenomena which move the
entire depth of the ocean (often several kilometers deep) rather than just
the surface, so they contain immense energy, propagate at high speeds and can
travel great trans-oceanic distances with little overall energy loss. A
tsunami can cause damage thousands of kilometers from its origin, so there
may be several hours between its creation and its impact on a coast, arriving
long after the seismic wave generated by the originating event arrives.
Although the total or overall loss of energy is small, the total energy is
spread over a larger and larger circumference as the wave travels. A single tsunami event may
involve a series of waves of varying heights; the set of waves is called a
train. In open water, tsunamis have extremely long periods (the time for the
next wave top to pass a point after the previous one), from minutes to hours,
and long wavelengths of up to several hundred kilometers. This is very
different from typical wind-generated swells on the ocean, which might have a
period of about 10 seconds and a wavelength of 150 meters. The actual height of a
tsunami wave in open water is often less than one meter. This is usually
unnoticeable to people on ships. The energy of a tsunami passes through the
entire water column to the sea bed, unlike surface waves, which typically
reach only down to a depth of 10 m or so. The wave travels across
open ocean at an average speed of 500 mph. As the wave approaches land, the
sea shallows and the wave no longer travels as quickly, so it begins to
'pile-up'; the wave-front becomes steeper and taller, and there is less
distance between crests. *While a person at the surface of deep water would
probably not even notice the tsunami, the wave can increase to a height of
six stories or more as it approaches the coastline and compresses. The
steepening process is analogous to the cracking of a tapered whip. As a wave
goes down the whip from handle to tip, the same energy is deposited in less
and less material, which then moves more violently as it receives this
energy. A wave becomes a
'shallow-water wave' when the ratio between the water depth and its
wavelength gets very small, and since a tsunami has an extremely large
wavelength (hundreds of kilometers), tsunamis act as a shallow-water wave
even in deep oceanic water. Tsunamis propagate outward
from their source, so coasts in the "shadow" of affected land
masses are usually fairly safe. However, tsunami waves can diffract around
land masses. It's also not necessary that they are symmetrical, as a tsunami
waves may be much stronger in one direction than another, depending on the
nature of the source and the surrounding geography. *A tsunami
has a much smaller amplitude (wave height) offshore, and a very long
wavelength (often hundreds of kilometers long), which is why they generally
pass unnoticed at sea, forming only a slight swell usually about 300 mm above
the normal sea surface. A tsunami can occur at any state of the tide and even
at low tide will still inundate coastal areas if the incoming waves surge
high enough.
There are three categories
of freak waves:
|
An imaging
ultrasound is a simple, safe and routine procedure using very high frequency (ultrasonic)
sound waves to "look inside" the body. Ultrasound imaging, also
called ultrasound scanning or sonography, involves exposing part of the body
to high-frequency sound waves to produce pictures of the inside of the body. Conventional ultrasound
displays the images in thin, flat sections of the body. Advancements in
ultrasound technology include three-dimensional (3-D) ultrasound that formats
the sound wave data into 3-D images. Four-dimensional (4-D) ultrasound is 3-D
ultrasound in motion. Benefits
Limitations:
Ultrasound is not an ideal
imaging technique for the bowel. Barium exams and CT scanning are the methods
of choice for bowel-related problems. Ultrasound waves do not
pass through air; therefore an evaluation of the stomach, small intestine and
large intestine may be limited. Intestinal gas may also prevent visualization
of deeper structures such as the pancreas and aorta. Patients who are obese
are more difficult to image because tissue attenuates (weakens) the sound
waves as they pass deeper into the body. Ultrasound has difficulty
penetrating bone and therefore can only see the outer surface of bony
structures and not what lies within. For visualizing internal structure of
bones or certain joints, other imaging modalities such as MRI are typically
used. Risks:
There are no known harmful effects. Doppler ultrasound is a special ultrasound technique
that evaluates blood as it flows through a blood vessel, including the body's
major arteries and veins in the abdomen, arms, legs and neck. There are
three types of Doppler ultrasound:
Ultrasound examinations can
help to diagnose a variety of conditions and to assess organ damage following
illness. Ultrasound
is used to help physicians diagnose symptoms such as:
Ultrasound
is a useful way of examining many of the body's internal organs, including
but not limited to the:
Ultrasound
is also used to:
Doppler
ultrasound images can help the physician to see and evaluate:
|
THE UNIVERSE - THE VOYGER TWIN MISSION |
Voyger 1 & 2 were launched from the planet Earth in the second half of 1977 towards a flyby of Juputer it's moons and that of the planet Saturn and its moon Titan on its never ending journey through the cosmos and onwards to infinity. Their mission. was to explore Jupiter and Saturn and beyond our solar system. This was a big task. No human-made object had ever attempted a journey like that before. At the behest of Astrophysicis Carl Sagen, the camera on the Voyger 1, was turned around for one last view of the planet Earth from 3.8 billion miles away, the image of the earth was less than 1 pixel, now referred to the Pale Blue Dot". It looked the size of the top of a pin head in the very dark and cold universe. Voyager 1 and 2 also discovered active volcanoes on Jupiter's moon Io, and much more. Voyager 2 also took pictures of Uranus and Neptune. Together, the Voyager missions discovered 22 moons. Since then, these spacecraft have continued to travel farther away from us. Voyager 1 and 2 are now so far away that they are in interstellar space—the region between the stars. No other spacecraft have ever flown this far away. Both spacecraft are still sending information back to Earth. This data will help us learn about conditions in the distant solar system and interstellar space. The Voyagers have enough fuel and power
to operate until 2025 and beyond. Sometime after this they will not be
able to communicate with Earth anymore. Unless something stops them,
they will continue to travel on and on, passing other stars after many
thousands of years. They are traveling in excess of 34,000 miles per
hour. Voyger 1 is now over 14.5 billion miles into his forever journey,
Voyger 2 now being over 12 billion plus miles from our Planet.. Each Voyager spacecraft also carries a message. Both spacecraft carry a golden record with scenes and sounds from Earth. The records also contain music and greetings in different languages. So, if intelligent life ever find these spacecraft, they may learn something about Earth and us as well! The Voyagers are now exploring the outermost reaches of our sun's influence, where the solar wind mixes with the interstellar wind of our galaxy. Their long-lived power source has enabled these explorers to continue teaching us about our solar system for more than years after they left earth. Voyager 1 and 2. The Voyager probes have since departed our solar system and moved into interstellar space,The Voyager 1 and 2 spacecraft were built by NASA's Jet Propulsion Laboratory, which continues to operate both. JPL is a division of Caltech in Pasadena, California. The closest star to our Solar System is Proxima Centauri, which is why it makes the most sense to plot an interstellar mission to this system first. As part of a triple star system called Alpha Centauri, Proxima ( a red dwarf star) is about 4.24 light-years from Earth. Voyager 1 will pass by Proxima Centauri within 16,000 years, while it will take 20,000 years for Voyager 2 to reach it, and 18,00 years to meet our neighboring star..And, for another example of distance - Pioneer 10 is on a different path and the first star that it will meet will be Ross 248, located 10 light-years away in the northern constellation of Andromeda. Astronomers have predicted that at some point in the next 80,000 years, Ross 248 will overtake Alpha Centauri to become the nearest star to our Sun, although only for a brief time. Pioneer 10 will pass by this star in approximately 34,000 years. Proxima Centauri lies at a distance of 39,900,000,000,000 kilometres, or 271,000 astronomical units, or 4.22 light years. It is slightly closer to Earth than Alpha Centauri A and Alpha Centauri B, which are 4.35 light years away. To illustrate what this means from our perspective: the Voyager 1 spacecraft is currently travelling away from Earth at upper limit of 81,000 years to travel to Proxima Centaura. On February 14, 1990, Voyager 1 took the first "family portrait" of the Solar System as seen from outside, which includes the image of planet Earth known as Pale Blue Dot. Soon afterward, its cameras were deactivated to conserve energy and computer resources for other equipment. The camera software has been removed from the spacecraft, so it would now be complex to get them working again. Earth-side software and computers for reading the images are also no longer available. In December 2017, NASA successfully fired up all four of Voyager 1's trajectory correction maneuver (TCM) thrusters for the first time since 1980. The TCM thrusters will be used in the place of a degraded set of jets which were used to help keep the probe's antenna pointed towards the Earth. Use of the TCM thrusters will allow Voyager 1 to continue to transmit data to NASA for two to three more years. Due to the diminishing electrical power available, the Voyager team has had to prioritize which instruments to keep on and which to turn off. Heaters and other spacecraft systems have been turned off one by one as part of power management. The fields and particles instruments that are the most likely to send back key data about the heliosphere and interstellar space have been prioritized to keep operating. Engineers expect the spacecraft to continue operating at least one science instrument until around 2025.Lastly, Voyager 1" is expected to reach the theorized Oort cloud in about 300 years and take about 30,000 years to pass through it, though it is not heading towards any particular star, in about 40,000 years, it will pass within 1.6 light-years (0.49 parsecs) of the star Gliese 445, which is at present in the constellation Camelopardalis and 17.1 light-years from Earth. That star is generally moving towards the Solar System at about 119 km/s (430,000 km/h; 270,000 mph). NASA says that "The Voyagers are destined—perhaps eternally—to wander the Milky Way." In 300,000 years, it will pass within less than 1 light year of the M3V star TYC 3135-52-1. As food for thought with these numbers presented to the reader, note that the Milky way is just the beginning, as there are billions of galaxies beyond. |
VOLCANOES |
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Over 80% of
the earth’s surface is of volcanic in origin. The sea floor and some
mountains were formed by numerous volcanic eruptions. Gaseous emissions
from volcano formed the earth's atmosphere. There are more than 500 active
volcanoes in the world. In excess of half of these volcanoes are part of the
"Ring of Fire," a region that encircles the Pacific Ocean. GASES: The major gases which are associated
with magma are carbon dioxide and water vapor. They can make-up a much as 14%
of the magma. These gases increase the violence of the eruption.
Fumarole: The yellow color around this
fumarole comes from sulfur crystals derived from the cooling of sulfur vapor
escaping from the fumarole opening. Very prominent in Hawaii in the
Kilauea Volcano and the surrounding areas of the caldera at Volcanoes
National Park. A volcanic
"vent" is where volcanic material is emitted. All volcanoes contain
a central vent underlying the summit
crater of the volcano. The volcano's cone-shaped
structure, or edifice, is built by the more-or-less symmetrical accumulation
of lava and/or pyroclastic material around
this central vent system. The central vent is connected at depth to a magma
chamber, which is the main storage area for the eruptive material. Because
volcano flanks are inherently unstable, they often contain fractures that
descend downward toward the central vent, or toward a shallow-level magma
chamber. Such fractures may occasionally tap the magma source and act as
conduits for flank eruptions along the sides of the volcanic edifice. These
eruptions can generate cone-shaped accumulations of volcanic material, called
parasitic cones. Fractures can also act as
conduits for escaping volcanic gases, which
are released at the surface through vent openings called fumaroles. Summit Crater: Parasitic Cones: The growth of parasitic cones on the flanks of large
composite volcanoes is a sign of old age. Not uncommonly, these cones develop
at successively lower levels as the volcanoes approach extinct. Usually, they
are made up of more basic and more siliceous differentiates. Parasites may be
concentrated along lines or belts that reflect structural trends in the
subvolcanic basement, or in a crudely concentric arrangement. The concentric
rings may reflect cone-sheets or ring dikes at depth. A crudely radial
arrangement of parasitic cones and domes is much more common. The number of
parasitic cones on most large composite cones is seldom more than ten or a
dozen.
Three main Types of
Volcanoes
|
Volt |
Volt is a unit of electromotive force, or difference of potential, which will
cause a current of one ampere to flow through a resistance of one ohm.
Named for Italian physicist Alessandro Volta. The
battery made by Volta is credited as one of the first electrochemical
cells. It consists of two electrodes: one made of zinc, the other of
copper. The electrolyte is either sulfuric acid mixed with water or a
form of saltwater brine. The electrolyte exists in the form 2 H+ and SO2−
|
WEATHER |
Storms: Thunderstorms,
Tornadoes, and Lightning Flash floods are the most
dangerous kind of floods, because they combine the destructive power of a
flood with incredible speed and unpredictability, sometimes in just a few
minutes and without any visible signs of rain. Flash floods often have a
dangerous wall of roaring water that carries rocks, mud, and other debris and
can sweep away most things in its path. Overland flooding occurs outside a
defined river or stream, such as when a levee is breached, but still can be
destructive. Flooding can also occur when a dam breaks, producing effects
similar to flash floods. Be aware of flood hazards
no matter where you live, but especially if you live in a low-lying area,
near water or downstream from a dam. Even very small streams, gullies,
creeks, culverts, dry streambeds, or low-lying ground that appear harmless in
dry weather can flood. Every state is at risk from this hazard.
Flash
floods are just one kind of flood. There are many different types of
flooding, a few are listed below. ATMOSPHERIC RIVER (AR)
A narrow, elongated flow of moist air in the lower atmosphere. The flow corridor measures is based on satellite observations, an atmospheric river is greater than 2,000 km (1,245 miles) long, less than 1,000 km (620 miles) wide, and averages 3 km (1.8 miles) in depth.
Atmospheric rivers, like the Pineapple Express, form along the front edge of slow-moving, low-pressure weather systems related to the polar jet stream. The cyclone nature of these weather systems in the northern hemisphere causes winds to flow from southwest to northeast. Hence, the warm moist air from the tropics reaches Americas West Coast traveling as far north as Washington and Oregon. This moisture transport occurs under particular combinations of wind, temperature, and pressure conditions.
Atmospheric rivers are typically located within the low-level jet, an area of strong winds in the lower levels of the atmosphere, ahead of the cold front in an extratropical cyclone. Studies have found that typical atmospheric river conditions last around 20 hours over an area on the coastline. Strong land-falling atmospheric rivers interact with topography and can deposit significant amounts of precipitation in relatively short periods of time leading to flooding and mudslides. Atmospheric rivers also can have beneficial impacts by contributing to increases in snowpack, such as in the western United States.
Hail is
formed in huge cumulonimbus clouds, commonly known as thunderheads. When the
ground is heated during the day by the sun, the air close to the ground is
heated as well. Hot air, being less dense and therefore lighter than cold
air, rises and cools. As it cools, its capacity for holding moisture
decreases. When the rising, warm air has cooled so much that it cannot retain
all of its moisture, water vapor condenses, forming puffy-looking clouds. The
condensing moisture releases heat of its own into the surrounding air,
causing the air to rise faster and give up even more moisture Cumulonimbus clouds contain
vast amounts of energy in the form of updrafts and downdrafts. These vertical
winds can reach speeds over 176 kilometers (110 miles) per hour. Hail grows
in the storm cloud's main updraft, where most of the cloud is in the form of
"supercooled" water. This is water that remains liquid although its
temperature is at or below 0 degrees Celsius (32 degrees Fahrenheit). At
temperatures higher than -40 degrees C (-40 degrees F), a supercooled water
drop needs something on which to freeze, or it remains liquid. Ice crystals,
frozen raindrops, dust, and salt from the ocean are also present in the
cloud. On collision, supercooled water will freeze onto any of these hosts,
creating new hailstones or enlarging those that already exist. Cross sections of
hailstones often reveal layers, much like those of an onion. These layers are
caused by the different rates of accumulation and freezing of supercooled
water, as the hailstone forms. When there is a great deal of supercooled
liquid in the air through which the hailstone falls, water accumulates faster
than it can freeze, so a coat of liquid forms. This becomes a layer of clear
ice when it does freeze. When a hailstone falls through air with a smaller
amount of liquid, the liquid freezes on contact with the hailstone, forming
small air bubbles in the opaque layers. The more supercooled water a hailstone
makes contact with, the larger and heavier the stone is likely to become.
When the hailstone becomes so heavy that the updraft can no longer support
it, it falls from the sky. Hail falls along paths
scientists call hail swaths. These vary from a few square acres to large
belts 16 kilometers (10 miles) wide and 160 kilometers (100 miles) long.
Swaths can leave hail piled so deep it has to be removed with a snow plow.
The
largest hailstone documented weighed 0.75 kilograms (1.67 pounds), and spans
14.4 centimeters (5.67 inches). It is estimated that 100
lightning flashes occur each second somewhere on the Earth, adding up to
nearly 8 million lightning flashes per day. All lightning is dangerous
and even the weakest thunderstorms produce lightning. Most people in recent
years have been killed by lightning while swimming, golfing, or hiking. But
they have also been killed doing less dangerous activities, like talking on
the telephone, playing soccer or baseball, fishing on a lake, taking a
shower, or loading laundry in a clothes dryer. Lightning is a chaotic and
dangerous aspect of weather. Lightning occurs most frequently during
thunderstorms, but has also been observed during volcanic eruptions,
extremely intense forest fires, and surface nuclear detonations. In a
thunderstorm, lightning is created as a discharge of built up energy due to
the separation of positive and negative charges which are generated inside
the thunderstorm. The formation of ice in a
cloud appears to be very important in the development of this charge
separation and ultimately of lightning. Inside a thunderstorm, these ice
particles vary in size, from small ice crystals to larger hailstones. Owing
to the rising and sinking air associated with thunderstorms, these particles
collide frequently inside the cloud. These collisions within the thunderstorm
cause these particles to build up electric charge. Due to the different rates
of rising and falling within a thunderstorm, a separation of electrical
charge takes place. As the thunderstorm grows, intense electrical fields can
develop within it. A large positive charge forms in the frozen upper part of
the cloud and two charge regions - a large, negatively charged region and a
smaller positively charged region - form in the lower portion of the cloud.
The ground normally maintains a small negative charge with respect to the
atmosphere, but when a thunderstorm drifts overhead, the negative charge at
the cloud base induces a positive charge on the ground below the storm. The
positive ground current follows the movement of the cloud like a shadow and
concentrates on elevated objects, such as trees, buildings, and higher
portions of terrain, in an attempt to establish a current to equalize the
charges between cloud base and ground. Air, however is a good insulator, and
the electrical potential between cloud and ground must build up to levels of
tens to hundreds of millions of volts before the insulating properties of the
air break down and an ionized conductive channel is established for the
current to flow between the two charges. If you have ever had your hair stand
on end while under a thunderstorm, you were in this positive ground current,
and could have become a lightning target. Lightning is usually
initiated within the thunderstorm cloud when a faint, negatively charged
channel called the stepped
leader emerges from the base of the cloud and propagates toward
the ground in a series of steps of about 1 microsecond in duration and
150-300 feet in length. The stepped leader reaches from cloud base to ground
in about a hundredth of a second. As the stepped leader approaches the
ground, streamers of positive charge rush upward from objects on the ground.
When one of the streams contacts the leading edge of the stepped leader, the
lightning channel is opened, negative charge starts flowing to the ground,
and a return stroke,
lasting about a tenth of a second, propagates through the channel as a bright
luminous pulse. Sometimes, following the initial return stroke, one or more
additional leaders may propagate down the decaying lightning channel at
intervals of about a tenth of a second. These leaders, called dart leaders, are not
stepped or branched like the original leader, but are more or less direct and
continuous. Like the stepped leader, however, they initiate return strokes.
These return strokes are what we call lightning. Not all lightning forms in
the negatively charged area low in the thunderstorm cloud. Some lightning
forms in the cirrus anvil at the top of the thunderstorm. This area carries a
large positive charge, and lightning from this area carries that positive
charge to a negative charged area on the ground. This type of lightning
stroke is particularly dangerous for several reasons. It frequently strikes away
from the rain core, either ahead or behind the thunderstorm. It can strike as
far as 5 or 10 miles from the storm in areas most people wouldn't consider to
be risky for lightning. The other problem is that positive lightning
typically has a longer duration, which results in more electrical charge
being transferred to the ground. This can allow for easier ignition of fires
and an increased risk to an individual. Thunder is the sound
produced by rapidly expanding gases along a lightning discharge channel where
air is instantaneously heated to temperatures near 10,000 degrees Celsius.
The shock wave that is created by this heating is what we hear as thunder.
Simply described, the Coriolis force accounts for why cyclones are counterclockwise-rotating storms in the Northern Hemisphere, but rotate clockwise in the Southern Hemisphere. The circulation directions result from interactions between moving masses of air and air masses moving with the rotating earth. Additionally, when one observes water draining from the sink, tub or toilet, the water goes down counter-clock wise, straight down or clockwise, this has to do with the design of the fixture. Also, it is said that the draining direction will almost always drain in the same direction. Further, it is thought that if one is at the equater and is up to 10' feet, above or below, the water draining will go straight down, and conversely, when north of the equater, the water will drain counter clock wise and clockwise when south of the equater. Science say's the Coriolis effect, it is not enough to dominate the flushing of a toilet--and the effect is weakest at the equator. Utilizing this weakness at the equator, this is why todays rocket departures take place near the equater, thus the rockets have less gravational resistance at take-off
ornadoes
are nature’s most violent storms. It is a violent rotating column of air
extending from a thunderstorm to the ground. Spawned from powerful thunderstorms,
tornadoes can cause fatalities and devastate a neighborhood in seconds. A
tornado appears as a rotating, funnel-shaped cloud that extends from a
thunderstorm to the ground with whirling winds that can reach 250 miles plus
per hour. Damage paths can be in excess of one mile wide and 50 miles long.
Every state is at some risk from this hazard. Tornadoes cause an average of
70 fatalities and 1,500 injuries in the U.S. each year, Before a tornado hits, the
wind may die down and the air may become very still. A cloud of debris can
mark the location of a tornado even if a funnel is not visible. Tornadoes
generally occur near the trailing edge of a thunderstorm. It is not uncommon
to see clear, sunlit skies behind a tornado. The following are facts
about tornadoes:
*Many
tornadoes occur throughout the world, but they are found most frequent in the
United States. ABOUT THE WIND:
The gases that make up our atmosphere and do interesting things as the temperatures change.
When gases warm up, the atoms and molecules move faster, spread out, and rise. That’s why steam coming off a pot of boiling water always goes upward. When air is colder, the gases get slower and closer together. Colder air sinks
Where wind happens. Gases move from high-pressure areas to low-pressure areas. And the bigger the difference between the pressures, the faster the air will move from the high to the low pressure. That rush of air is the wind we experience.
The sun warms up the air, but unevenly, this is because the sun hits different parts of the Earth at different angles, and because Earth has oceans, mountains, and other features, some places are warmer than others. Because of this, we get pockets of warm air and cold air.
Since gases behave differently at different temperatures, that means you also get pockets with high pressure and pockets with low pressure. In areas of high pressure, the gases in the air are more crowded. In low pressure zones, the gases are a little more spread out.
Four
types of storms that produce Wind
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Founded in December 1904 by George Ellery Hale as one of the original scientific enterprises of the Carnegie Institution of Washington, Mt. Wilson Observatory is completing its first century as one of the world's premier astronomical observatories. During the first half of the twentieth century Mt. Wilson was successively home to the world's two largest telescopes as well as the most powerful facilities in existence for studying the sun. The 60-inch and 100-inch night-time telescopes and the 60-ft and 150-ft solar tower telescopes in the hands of the brilliant scientists who used them revolutionized astronomy through such discoveries as:
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THE WORLD WIDE WEB was invented at CERN in 1989 by Tim Berners-Lee
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1 mrem per
year is a negligible dose of radiation, and 25 mrem per year from a single
source is the upper limit of safe radiation exposure. Too much radiation at
one body site can cause skin conditions resembling severe burns or local
cancers. Widely distributed over the body so that it penetrates much of the
blood-forming marrow, excessive radiation can cause leukemia. X-radiation is produced by
X-ray tubes in which energetic electrons smash into a tungsten target
(sometimes it is molybdenum or other material). When the electrons are
stopped by the target, they very occasionally emit an X-ray photon. X-rays are useful to
medicine because they can pass right through the body to cast shadow
pictures. They best portray large differences in atomic number (e.g., bone
versus soft tissue) and differences in density (air versus anything else).
They don’t do as well at distinguishing soft tissues from each other except
for specialized exams like mammography for breast cancer detection. Often
special “contrast agents” are injected or swallowed, such as iodine compounds
to visualize blood vessels, or barium for the stomach. X-ray imaging systems have
higher spatial resolution than MRI or ultrasound, and are the method of
choice for assessing fractures. X-ray images can be acquired and displayed in
real time on a TV monitor which makes them very useful for following motion
such as swallowing or of blood flow through an organ. The principals of fluoroscopy are much the same as with
film x-ray (called radiography) described above. However, fluoroscopic
imaging yields a moving x-ray picture or movie. The original
"fluoroscopes" consisted of an x-ray system and a fluorescent
screen which registered the x-rays and emitted glowing light. The doctor could
watch the fluorescent screen and see a dynamic (moving) image of the
patient's body (for example the beating heart). Fluoroscopic technology
improved greatly with the addition of television cameras and fluoroscopic
"image intensifiers". Backscatter X-ray is a newer imaging system which
detects the radiation which comes back from the target. It has potential
applications in almost every situation in which non-destructive examination
is required, but only one side is available for examination. The resolution of the
resulting images is quite high. Some backscatter X-ray scanners are able to
penetrate up to 30cm (~12") of solid steel. As such, the technology is
in use to search containers and trucks much more quickly than performing a
physical search, and potentially allow a larger percentage of shipping to be
checked for smuggled items or weapons. According to Farren Technology, the
technology exists to scan areas as far as 50 meters away from the device,
producing 3D images of people's bodies and the weapons they might be hiding.
In comparison to x-rays from medical applications, the backscattered x-rays
are considered high energy and usually scatter instead of penetrate
materials. A "high energy x-ray beam" moves rapidly over the
person's form and a high resolution image of the person's body is
constructed when the scattered x-ray "from a known position" is
detected. MILLIREMS
X-Rays are
something many people will want to avoid, at the least minimumly unless absolutely necessary. X-Rays
are not the best diagnostic tool for all things. How much radiation does a
person receive in an average dental X-Ray? for a comparison, measured in
millirems; the standard measure of radiation absorption by human cells: Flight from Los Angeles to
Paris (cosmic rays) 4.8 Millirems. Chest X Ray (l film) 6-30
Millirems. Contamination 1/2 mile from
Three Mile Island during nuclear accident 83.0 Millirems. Apollo X astronauts on moon
flight (cosmic rays) 480.0 Millirems. Dental X-ray (whole mouth)
25-36 Millirems. On-site dose at Three Mile
Island accident 1100.0 Millirems. Breast mammography (1 film)
1500.0 Millirems. Current N.A.S. yearly
occupational exposure accumulative limit is 5000.0 Millirems. |
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