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The Electromagnetic Spectrum

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Title: The Electromagnetic Spectrum


1
The Electromagnetic Spectrum
  • By Christopher Wainwright Aaron Tom Baroni

2
What is it?
  • The electromagnetic spectrum is the complete
    spectrum or continuum of light including radio
    waves, infrared, visible light, ultraviolet
    light, X-rays and gamma rays
  • An electromagnetic wave consists of electric and
    magnetic fields which vibrates thus making waves.

3
The Electromagnetic Spectrum
  • By Christopher Wainwright Aaron Tom Baroni

4
Nature of Electromagnetic Waves
  • They are Transverse waves without a medium. (They
    can travel through empty space)
  • They travel as vibrations in electrical and
    magnetic fields.
  • Have some magnetic and some electrical
    properties to them.
  • Speed of electromagnetic waves 300,000,000
    meters/second (Takes light 8 minutes to move from
    the sun to earth 150 million miles at this
    speed.)

5
  • Waves or Particles
  • Electromagnetic radiation has properties of waves
    but also can be thought of as a stream of
    particles.
  • Example Light
  • Light as a wave Light behaves as a transverse
    wave which we can filter using polarized lenses.
  • Light as particles (photons)
  • When directed at a substance light can knock
    electrons off of a substance (Photoelectric
    effect)

6
Wavelength, Frequency and Energy
  • Since all light travels at the same speed,
    wavelength and frequency have an indirect
    relationship.
  • Light with a short wavelength will have a high
    frequency and light with a long wavelength will
    have a low frequency.
  • Light with short wavelengths has high energy and
    long wavelength has low energy

7
RADIO WAVES
  • A. Have the longest wavelengths and lowest
    frequencies of all the electromagnetic waves.
  • B. A radio picks up radio waves through an
    antenna and converts it to sound waves.
  • C. Each radio station in an area broadcasts at a
    different frequency. on radio dial tells
    frequency.
  • D. MRI (MAGNETIC RESONACE IMAGING)
  • Uses Short wave radio waves with a magnet to
    create an image

8
Bands of Radio/TV/Microwaves
9
Microwaves
  • Longer than radio, shorter than light and
    infrared
  • Wavelength 1 x 10 - 4 m to 1 x 10-1 m
  • First used in radar, now used in communication,
    medicine and consumer use (microwave ovens)

10
Infrared waves
  • Invisible electromagnetic waves that are detected
    as heat
  • Can be detected with special devices such as
    night goggles
  • Used in heat lamps
  • Higher energy than microwaves but lower than
    visible light

11
Visible Light
  • The portion of the electromagnetic spectrum that
    human eyes can detect
  • ROY G BIV (red, orange, yellow, green, blue,
    indigo, violet)
  • Red is the lowest frequency and violet is the
    highest frequency

12
Ultraviolet waves
  • Higher energy than light waves
  • Can cause skin cancer and blindness in humans
  • Used in tanning beds and sterilizing equipment

13
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14
X-Rays
  • High energy waves
  • First discovered by Roentgen
  • Used in medicine, industry and astronomy
  • Can cause cancer

15
GAMMA RAYS
  • Shorter wavelength and higher frequency than
    X-rays
  • Carry the greatest amount of energy and penetrate
    the most.
  • Used in radiation treatment to kill cancer cells.
  • Can be very harmful if not used correctly.

16
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17
Test Time
  • 1. What is the relationship between frequency and
    wavelength?
  • 2. What is meant by spectrum?
  • 3. What does ROY G BIV mean?

18
Now, lets really think
  • 4. Can you actually see x-rays?
  • Support your answer.
  • 5. Which color is more energetic, red or yellow?
  • 6. Which type of wave travels faster, gamma or
    radio?
  • 7. Why are microwaves more dangerous than radio
    waves?

19
Answers
  • 1. Frequency and wavelength are properties of
    waves and since speed is constant for em waves,
    as frequency increases, wavelength decreases.
  • 2. Spectrum is a continuum of all electromagnetic
    waves
  • 3, ROY G BIV is the difference colors of the
    visible light in order of longest wavelength to
    shortest wavelength.
  • 4. X-rays can not be seen, only the waves in the
    visible light portion are visible.
  • 5. Yellow is higher energy than red because it
    has a shorter wavelength and higher frequency.
  • 6. Both travel at the same speed, 300,000 km/s
    (all em waves travel at the same speed)
  • 7. Microwaves have a higher frequency than radio
    and carry more energy.

20
References
  • en.wikipedia.org/wiki/Electromagnetic_spectrum
  • imagine.gsfc.nasa.gov/docs/science/know.../emspect
    rum.html
  • hyperphysics.phy-astr.gsu.edu
  • science.hq.nasa.gov/kids/imagers/ems/ems.html

21
The Electromagnetic spectrum
  • By Anna Proctor Lindsey Ferris

22
What the heck is the electromagnetic spectrum?!
  • The Electromagnetic Spectrum is the range of all
    possible frequencies of electromagnetic
    radiation, or waves.
  • It distributes or absorbs radiation through
    different objects.
  • The full set of waves that can travel through
    space includes not only visible light but short
    waves.

23
How colors are used to show the level of
frequencies.
  • A special device is used to control the movement
    of electromagnetic waves. These waveguides are
    typically metal-based lines pitched at microwave
    frequencies to link connections between antennas
    and receivers. Its a one-way channel that picks
    up signals and an attenuator keeps the signals
    strength at a constant.

24
Different types of radiation
  • Radio waves are the longest wavelength in the
    electromagnetic spectrum.
  • Infra red light is associated with heat and
    things that give off heat. Ex TV remote controls.
  • Visible light is the only thing our eyes can
    detect in the Electromagnetic spectrum.
  • Ultra-violet light is made by special lamps which
    in other words, replaces to sun. Ex tanning beds.

25
More types of radiation
  • Microwaves are transmitted through mobile phones.
  • Gamma rays are the highest frequency waves
  • X-rays are waves used to inspect luggage at an
    airport or to see through human skin to their
    bones.

26
Measurements of the electromagnetic spectrum.
  • The tiniest waves are measured in angstroms, a
    unit of length equal to one hundred-millionth of
    a centimeter.
  • Waves of visible light are measured in
    nanometers (nm).
  • While waves in infrared to radio are measured in
    more familiar meters.

27
How else can wavelengths be measured?
The electromagnetic spectrum can be expressed in
terms of energy, wavelength, or frequency.
28
Visible wavelengths!
  • Are the only electromagnetic waves we can see. We
    see these waves as the colors of the rainbow.
    Each color has a different wavelength. Red has
    the longest wavelength and violet has the
    shortest wavelength. When all the waves are seen
    together, they make white light.

Each color of the rainbow corresponds to a
different wavelength of the electromagnetic
spectrum.
29
This chart shows all the different colors and how
they are in relation to one another.


  • Color Charts

30
A closer look at colors.
  • This a picture at normal size, then blown up
    200, 400 and 800 times. Most pictures in magazine
    are made up of colored dots.
  • A magazine printing press usually can only print
    four colors Cyan, Magenta, Yellow, and Black.
    Our eyes and brain put colors together from the
    colored dots.

31
QUIZ TIMEEE.


  • QUIZ TIMEEE.

32
Sources.
  • http//www.learner.org/teacherslab/science/light/c
    olor/dots/index.html
  • http//imagine.gsfc.nasa.gov/docs/science/know_l2/
    emspectrum.html
  • http//science.hq.nasa.gov/kids/imagers/ems/ems.ht
    ml
  • http//home.clara.net/darvill/emag/index.htm
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