7/29/2019 Radiation is in Fact Energy That Travels in Space
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Radiation is in fact energy that travels in space. More
specifically, electromagnetic
radiation can be defined as being composed of particles without
mass (also calledphotons) which travel at the speed of light in a
wave-like pattern. It is the energy of those
photons that is used as criteria to classify various types of
electromagnetic radiation.
Thus, there are various types of radiations, all being
electromagnetic radiation. The
following is the increasing order of wavelength and decreasing
order of energy and alsoof frequency between various types of
electromagnetic radiation: Gamma-ray X-Ray
Ultraviolet light Visible light Infrared light Microwaves Radio
waves Below are
examples and a brief discussion for each type of radiation:
Gamma-rays have the highestenergy and frequency and the lowest
wavelength. They are emitted by radioactive
materials when they undergo nuclear fission such as through the
detonation of nuclear
weapons and by the generation of power in nuclear power plants.
X-Rays - are used inmedicine. In Universe, hot gases may emit
X-Rays. Ultraviolet lightis emitted by the
sun and other hot objects in the space; Visible light that is
the only radiation type that
we can perceive. It is emitted by everything: objects and living
beings, plants, and even
by stars! This is why we see what we see. Infrared lightis
emitted by human body
(specifically by skin), which is why we can be seen in the night
by using night-visiondevices (goggles). Infrared light is also used
in space research to map the dust between
stars. Microwavesare emitted in the microwave ovens and by
radars. They are used inspace research to study the structure of
galaxies. Radio waves have the lowest energy and
frequency but the highest wavelength. They are emitted by radio
transmitters, TVs, etc.
The radio waves are also emitted by stars and gases in the
Universe and may be used in
astronomy research. Radioactive materials are those materials or
elements that emitradiation, thus they are not stable and get
transformed into other radioactive or non-
radioactive materials. The harm that can e caused by various
radioactive elements is
function of their half time (the time needed for their
concentration to be reduced to halfdue to radioactive decay
processes). Basically, the higher the half-time, the lower is
the
threat to human health. There are those radioactive elements
with a short and very-short
half-time that pose high safety risks. Examples of radioactive
elements and their use.
There are many radioactive elements (materials) in nature, of
which the most used (e.g.,in nuclear power plants, nuclear weapons)
are: Caesium-137, Strontium-90, Plutonium-
238 (primary material in nuclear weapons), Uranium-235. Another
almost classic
example of radioactive element is carbon-14 (C-14) which is
commonly used to age-date materials from living organisms over very
large periods of time. This is because C14
has a very high half time (of more than a thousand years). C-14
is also used in research
projects as a tracer. There are many other radioactive elements
with beneficial use,including: Cesium-137 (used to treat cancers),
Chromium-51 (used in studies of red
blood cell survival), Cobalt-57 and Cobalt-60(in nuclear
medicine ), Calcium-47 (in
biomedical research), Iodine-123 (to diagnose thyroid diseases),
Krypton-85 (in indicator
lights), Nickel-63 (in detection of explosives), Radium-226 (in
lightning rods),Strontium-85 (in study of bone formation),
Thorium-229 (in fluorescent lights), Tritium
(in drug metabolism studies), Uranium-234 (in dental fixtures
like crowns). Many
radioactive materials have half lives of hundreds of thousands
of years and thus, once
generated, may persist in environment for very long time. Radon
is also a commonradioactive element with about 55% of our natural
radiation exposure caused by this
element.
