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Electromagnetic
Spectrum
What is the
Electromagnetic Spectrum?
The electromagnetic spectrum is the entire
range of radiation.
What is radiation?
Radiation is all energy that is released in
the form of waves (or rays)
Electromagnetic radiation – energy carried through space in the form of
waves.
What are some examples of
radiation?
1. Gamma Rays
Gamma-ray bursts are the most powerful events
in the universe, temporarily outshining several
galaxies and likely signaling the birth of a black
hole.
What are some uses for radiation?
Gamma Rays are used
• in the sterilization of medical equipment
by killing bacteria.
• to kill bacteria and insects in Food
What are some examples of
radiation?
2. X-Rays
• X-rays can penetrate
most materials except
lead shielding. When they
were discovered, the "X"
stood for "unknown,"
because they were so
mysterious. The name has
been used ever since.
What are some uses for radiation?
X-Rays are used to…
• examine luggage and in airports
• detect structural problems and cracks in
airplanes and bridges
•most common use of x-rays is in medicine and
dentistry
What are some examples of
radiation?
3. Ultraviolet Rays
The name means "beyond
violet” since violet is the
color with the shortest
wavelength in the visible
light spectrum.
And, UV has even a
shorter wavelength than
violet!
UV rays from a
tanning bed
What are some uses for radiation?
UV rays are used in…
• Security; to help thwart counterfeiters.
• Forensics; helpful in locating and identifying
bodily fluids (blood)
What are some examples of
radiation?
4. Visible Light Rays
The type of radiation that
can be detected by human
eyes.
It contains the colors of
ROYGBIV.
What colors make up
visible light?
Visible Light Rays contain ROYGBIV
•
•
•
•
•
•
•
Red
Orange
Yellow
Green
Blue
Indigo
Violet
What are some examples of
radiation?
5. Infrared Rays
Infra means below; Infrared
rays have longer wavelengths
than visible red light.
They are the barely visible,
deep red rays you get from a
heat lamp.
What are some uses for radiation?
Infrared rays are used in…
• Photography - to take pictures in places where there is
no visible light.
• Military uses include night vision goggles, etc.
• And, remote controls, burglar alarms also use infrared.
What are some examples of
radiation?
6. Microwaves
-have wavelengths that can be
measured in centimeters!
-The longer microwaves, those closer
to 30 cm, are the ones which heat our
food in microwave ovens.
-Shorter microwaves are used in
remote sensing. These waves are
used for radar like doppler, used in
weather forecasts.
What are some uses for radiation?
Microwaves are used for…
• Communication; Cable, broadband, bluetooth, before fiber
optics, most long distance phone calls were sent via microwave.
• Remote sensing; radars use microwaves to detect range and
speed of remote objects. Used in doppler radar weather, air
traffic control, navigation of ships, and of course, speed limit
enforcement.
•Navigation; Global Positioning Systems (GPS) use microwaves
•Heating Food
What are some examples of
radiation?
7. Radio Waves
-Radio waves have the longest wavelengths in the
electromagnetic spectrum. These waves can be longer than
a football field or as short as a football.
What are some uses for radiation?
Radio waves are used for…
• Radios and TV’s.
• Garage door openers, alarm systems, radio controlled toys.
Electromagnetic Radiation
Let’s summarize…
The entire range of radiation includes…
1.
2.
3.
4.
5.
6.
7.
Gamma Rays
X-rays
Ultraviolet rays
Visible light rays
Infrared rays
Microwaves
Radio waves
Electromagnetic Radiation
Radio waves have the longest wavelength and the lowest
frequency.
Gamma rays have the shortest wavelength and the highest
frequency.
Electromagnetic Radiation
With visible light…
Red has the longest wavelength of all the colors.
Violet has the shortest wavelength of all the colors.