1. wave- up and down movement of energy from one place to another

2. electromagnetic waves (EM waves)- electric and magnetic energy that travels through empty space in the form of waves moving at the “speed of light”. Stars emit every type of EM wave.

3. electromagnetic spectrum (EMS)- all the different types of EM wave, from the longest wavelengths (radio waves) to the shortest wavelengths (gamma rays).

7. Each different type of EM wave has its own unique properties, effects, and uses.

9. RADIO WAVES: longest w, lowest f, least energy
GAMMA RAYS: shortest w, highest f, most energy

10. Humans cannot see EM radiation (except visible light, as colors) since most wavelengths are too short or too long to be sensed by our eyes.
Humans cannot feel EM radiation (except infrared, as heat) since most wavelengths are too short or too long to be sensed by the nerves in our skin.

11. RADIO WAVES

12. USES: Radio signals, TV broadcast, satellite communications
USES: Radio signals, TV broadcast, satellite communications. Emitted by radio antennae and by stars. May be sent by aliens?
EFFECTS: They have the lowest energy, so they are harmless.

13. Microwaves

14. USES: Cell phones,
radar, cooking.

15. Infrared Waves

16. USES: fast food heat lamps, finding people in the dark, measuring temperature
SOURCES:
anything
warm
Infrared spy camera

17. VISIBLE LIGHT - the only EM waves humans can SEE!
Makes up only a very small part of the EM spectrum!
Has medium wavelength and medium energy, so it is not harmful to organisms.

18. Ultraviolet (UV) Waves
Fluorescent minerals

19. USES: tanning
EFFECTS: Has more energy than visible light, so it may damage skin cells, may cause cancer
SOURCES:
Stars
(like the
SUN)
Skin cancer on a man’s arm

20. The earth’s atmosphere contains a very special layer...

21. … called the OZONE LAYER.
The ozone layer protects humans (and other organisms) from the sun’s UV rays.

23. A large hole has been developing in the ozone layer since the 1970s
A large hole has been developing in the ozone layer since the 1970s. The hole is directly above Antarctica, at the South Pole.

24. The hole in the OZONE LAYER.

25. X-RAYS

29. USES: to see inside the body, to see inside luggage, to kill cancer cells, sterilize medical equipment
EFFECTS: Has a lot of energy, so it may damage DNA, may cause cancer

30. Mushroom cloud from atomic bomb
GAMMA RAYS

31. GAMMA RAYS
EFFECTS: may damage DNA, may lead to cancer or radiation sickness
SOURCES: radioactive elements (U, Ra, Cs-137, Ir-92, Co-60,K-40,Tc-99), nuclear explosions, stars, supernovae

32. GAMMA RAYS
USES: see inside the body, measure blood flow, kill cancer cells (radiation therapy), measure the thickness of metal, find leaks in pipes, strengthen materials, sterilize food & medical equipment, measure properties of rock and soil.

34. The vertical illustration of the different regions of the e-m spectrum and their common uses was done by Design at Work for the curriculum supplement "Human Physiology in Space" by Barbara F. Lujan and Ronald J. White, Used by permission.