Essay/Term paper: Electromagnetic spectrum

Essay, term paper, research paper:  Medicine

The electromagnetic spectrum is made up of six different types of
waves. Radio waves, Microwaves, Infrared waves, Visible light, Ultraviolet
light, X-rays and Gamma rays. The radio waves are used to transmit radio
and television signals. The infrared waves are used to tell temperature
of areas. Visible light is all the colors that we can see. Ultraviolet
light can help things grow but to much can cause diseases such as skin
cancer. X-rays are used as a tool to find broken bones or take pitchers of
our sun. Gamma rays are used in medical science but they are oftenly used
to produce images of our universe. If you would like to know more about
the spectrum keep reading.



The electromagnetic spectrum is the organization of six diferent
wavelengths. Each having their own use. The spectrum in order from longest
to shortest wavelengths is: Radio waves, Microwaves, Infrared waves,
Visible light, Ultraviolet light, X-rays and Gamma rays. The most
familiar forms of the spectrum are radio waves and light waves. The
reason for that is, that we listen to the radio or use its waves more
often than we think. For instance cell phones work off of radio waves.
Light waves are used more often than we think because with out light we
wouldent posibly be able to see color on any thing, or we wouldent have
photosynthisis which sunlight is used for. The term spectrum refers to
light in general or the whole range of electromagnetic radiation. The
electromagnetic field was found in the 19th centurie. It was founded by
James Clerk MAXWELL of Scotland and published in 1865. The field is
described in two quantities the electric component E and the magnetic
component B and both charge in space and time. This meaning
electric / magnetic / spectrum.
Radio waves are used to transmit radio and television signals.
Radio waves can send sounds at the speed of light. The range of radio
waves can be less than a centimeter to tens or even hundredths of meters.
Radio waves are produced by coherent motion of electrons such as the
antenna of a radio transmitter. Coherent motion is the focused pattern of
the waves, in this case. The radio waves are also produced by charged
particles orbiting in magnetic fields. As you already know we have FM and
AM radio waves. Well an FM radio station at 100 on the radio dial (100
megahertz) would have a wavelength of about 400 meters. A radio wave can
also be used to create images such as portable TVs. Radio waves with
wavelengths of a few centimeters can be transmitted from a satellite or
airplane antenna. The reflected waves can be used to form an image of the
ground in complete darkness or through clouds. This would be how spy
satellites work or how we take pictures of the planets surface.
Following after radio waves would be the magnificent microwave.
The microwave makes up a very small part of the spectrum although it is
widely used throughout house holds across the world. Microwaves range from
a few centimeters to 0.1 cm. The wave is used to heat your food. It heats
your food by bouncing back and fourth across the microwave walls. In the
process it causes molecules (tiny particles) to vibrate and create
friction which in turn creates heat.
Infrared is the region of the electromagnetic spectrum that
extends from the visible region to about one millimeter (in wavelength)
Infrared waves include thermal radiation. For example hot or burning
charcoal may not give off light but it does send out radiation its just
felt as heat. The infrared radiation is or can be measured using detectors
. Infrared has many applications in medicine or finding heat leaks in
houses. This is what gives us the ability to see in the dark with infrared
goggles to tell us what is putting off heat . It is also used in space
science exploration to tell us the climate of other planets or even the
heat of the sun.
The rainbow of colors we know as visible light is the portion of
the electromagnetic spectrum with wavelengths. A wavelength is the
distance between consecutive peaks of consecutive valleys in wave form.
The reason we can see all the colors we do is simple. The light of the
world reflects off the objects giving it color. Such as when it is sunny
out every thing the sun hits is more visible and we can see its color. The
moon works the same way it's just less light making it harder to see the
color. Now Im a scuba diver and when I go under water the last color I see
is blue. The color of the water once under water I can no longer see color
except for what little portion of the sun that peers down through the
water giving every thing a grayish color. But when I bring a dive light
down with me I can actually see every thing's color. Thats why swim wear
is reflective so you can see it under the water or not.
Ultraviolet radiation has a range of wavelengths from 400
billionths of a meter to about 10 billionths of a meter. Small amounts of
ultraviolet radiation can help us do things such as helping the plants
grow through the process of photosynthesis, but larger doses can cause
diseases, like skin cancer. Ultraviolet wavelengths are used periodically
throughout astronomical observatories, and some remote sensing.
Observations of the earth are also concerned with the measurement of the
ozone layer. The reason for that is that if we didnt have the ozone layer
all of the Suns ultraviolet radiation would rain down giving us skin
cancer and destroying all vegetation.
X-rays are high energy waves which have great penetration power
They are used in medical science, and in inspecting welds. X-ray images of
our sun can give us important clues to solar flares and other changes on
our sun that can effect space weather. The wavelengths from x-rays are
about 10 billionths of a meter to about 10 trillionths of a meter. X-rays
are produced when atoms are bombarded by high energy electrons.
Gamma rays behave like x-rays of very short wavelengths. They
have wavelengths of less than about 10 trillionths of a meter which makes
them more penetrating than an x-ray . These rays are generated in
radioactive atoms and in nuclear explosions. Gamma rays are used in many
medical applications such as taking pictures of bone structure slightly
deeper than an x-ray would go. Gamma rays can also produce images of our
universe giving us valuable information on the life and death of stares or
any other violent process in the universe.
All the electromagnetic waves need no material for transmission.
There for radio waves can travel through intercellular space from the
stars or planets to Earth regardless of their frequency and wavelength.
Electromagnetic waves travel at a speed of 299,792 km (186,282 mi.) Per
second in a vacuum. Wavelengths and their frequency are important in
determining their heating effect, visibility, penetration.
The Near-Earth Asteroid rendezvous mission. Is going out to study
the Asteroids around Earth. This space craft will be using tools from the
electromagnetic spectrum. The two tools NEAR will be using are x-rays and
gamma rays. The mission will measure and map the abundance of various
elements of the surface of Eros. Since the suns rays bounce off of Eros
we will be studying it first. The rays cause Eros to give off different
elements. That our x-rays will be able to study. The x-rays will help
study the suns beam on to Eros telling us what elements are on it. They
will also be able to take clear images of Eros surface. The Gamma rays
will be used to study the elements 10 to 20 cm below the surface of Eros.
The gamma ray dose this by beaming down to the surface of Eros getting
absorbed in to the material allowing it to reach a certain point before it
is completely absorbed. And since a gamma ray is more penetrating than an
X-ray it would be able to reach farther down into the surface of Eros
before it is completely absorbed. This mission will give us a valuable
edge on the portion of the elements on asteroids' comets or meteors around
Earths orbit. This is one classic example of the uses of the
electromagnetic spectrum.
When you go scuba diving under water you lose half the colors that
you would normally see above water. All of the Warmer colors such as the
reds' oranges and yellows are absorbed by the water, except for the
tropical waters which of course are warmer causing the water to be less
dense making it easier to see.. As you descend to greater depths all you
can see are the blues and grays. Now when you bring your dive light down
with you you're able to see all the different colors again. Their for
visible light comes from the Sun, or from extremely powerful lights but
the lesser the wattage the less color it will show. When the Sun shines on
your shirt part of its ray is absorbed giving it a color. That is how
color is brought into our world.
Earlier in the report cell phones were mentioned and how they were
related to the spectrum. Now you will learn how and maybe some new
technology from Global Communications. Cell phones operate on high
frequency radio technology and ultra-sophisticated phone switching
devices. Cell phones bounce off of satellites scattered in space and on
Earth. Allowing your cell phone to reach great distances so you can talk
to that special someone, whether you are caught in a traffic jam or your
plane flight is delayed. You will be able to call them to let them know
that you will be running late. No matter what you use it for its about to
take another step to make it even easier for you to use. Just imagine
being able to put a cell phone in your pocket or having a cell phone that
can be voice activated. That means hands free no more accidentally hitting
that speed dial to your mother in law. Just think of all the possibilities
that you have coming your way in global communications.
Up to the twentieth century, reality was everything humans could
touch, smell, see and hear. Since the initial publication of the chart of
the electromagnetic spectrum...humans have learned that what they can
touch, smell, see, and here is less than one-millionth of reality.
Ninety-nine percent of all that is going to affect our tomorrows is
developed by humans using instruments and working in ranges of reality
that are nonhumanly sensible.
By, (R. Buckminster Fuller)

Up until the nineteenth century we werent able to use all of the
technology that we have to day. For instance if someone broke there arm
they would have to deal with it in other ways unlike now when doctors can
do an x-ray and know how to fix the problem. Back in the day we werent
even able to listen to the radio in our horse drawn carriage. But now in
this new age of technology we are able to do all sorts of things all
thanks to the electromagnetic spectrum. Now to close this report off Im
going to simply ask you to go do some more studying on this topic maybe
you will find it just as interesting as I have.











Vocabulary
Wave-moving disturbance; a deformation of the transport medium which
propagates through the medium."
Example- A cork bobbing up and down on the surface of a pond shows
that a disturbance is passing other than a flow of water
(current)
Fact-The purpose of a wave is to transport energy from one point to
another.
Wavelength-distance between consecutive peaks or consecutive valleys in
wave form. Units for wavelengths are units of distance such as centimeters
or Armstrongs.
Crest-highest part of wave.
Trough-lowest part of wave.
Light- Electromagnetic radiation that makes vision possible.
Frequency- The number of crests (or troughs) that pass a place in a
certain time in the waves frequency.
Nanometer- One billionth.
Angstroms- Ten billionth.











Bibliography:
Internet:
Http://hurlbut.jhuapl.edu/NEAR/Eucational/lessonSpectrum/lpspec.html
http://www.mymate.demon.co.uk/em.htm
http://www.physics.gmu.edu/classinfo/astr103/CourseNotes/rad_wave.htm
http://www.li.net/~stmarya/stm/gamm_1.htm..
http://cossc.gsfc.nasa.gov/cossc/nasm/VU/overview/whatare/whatare.html
Books:
Grolier Encyclopedia, 1996
ElectrIcity and Magnetism, Prentice-Hall, 1993
Scott Forman, Physical Science Bell and Howell Company 1977
Readers digest-How In The World Library of congress, 1990
Adventures In Scuba Diving, NAUI, 1996
Eric M. Rogers, Physics For The Inquiring Mind Princeton, New Jersey
Princeton University Press, 1960
Magazine:
Global Communications OMNI, November 1990
Acknologements:
I would like to thank Mr. Rhan for giving me the time to work on the
electromagnetic spectrum during his math class period. And I would also
like to thank that stupid voice in my head for keeping me on task, against
my will. I cant forget good old Mr. Garcia for giving me such a short time
to finish this but the confidence it took to succeed as well. And my dear
old dad since he asked me to thank him too.