1. Electromagnetic Spectrum

2. Electromagnetic Spectrum
MOST energy
LEAST energy
The range of electromagnetic waves when they are placed in order of increasing frequency
This Photo by Unknown Author is licensed under CC BY-NC
Low frequencies waves have the LEAST energy and high frequencies waves produce the MOST energy
This Photo by Unknown Author is licensed under CC BY-NC-ND
Farther apart
Closer together

3. Characteristics of e.m. waves
They all travel at light speed, but have different wavelengths and different frequencies
Long and Low
Used for space exploration because they DO NOT need a medium (substance) in order to travel
Short and High
As the wavelength decreases, frequency increases

4. Frequency vs. Wavelength
Short and High
Long and Low

5. To help you remember the order…
Long and Low
Radio
Microwave
Infrared
Visible
Ultra-violet
X-ray
Gamma
Raging
Martians
Invaded
Venus
Using
X-ray
Guns
Short and High

6. Let’s look at each individual wave

7. Longest wavelength and lowest frequencies
Radio waves
Uses:
1. Learn about the composition and motion of stars, planets, comets, dust and gas
2. Radio, television, and cell phone signals
3. Communication (ships, airplanes)
Longest wavelength and lowest frequencies
4. MRI – pictures of the inside of the human body

8. Long wavelength and low frequency
Microwaves
Uses:
1. Cook food
2. Radar (weather)
3. Portions of phone calls
4. Learn about the structure of nearby galaxies
Long wavelength and low frequency

9. Long wavelength and low frequencies
Infrared
Uses:
1. Show heat loss
2. Night vision googles – pick up infrared light emitted by objects with heat
3. Map the dust between stars
Long wavelength and low frequencies

10. Medium wavelength and medium frequencies
Visible light
Uses:
1. Allows us to see – the only part we can see!
2. Creates a rainbow (ROYGBIV)
3. Stars also emit visible light
Medium wavelength and medium frequencies

11. The next waves have higher energy and are considered more dangerous

12. Short wavelength and short frequencies
ultraviolet
Uses:
1. Kills germs
2. Creates a tan OR even a sunburn
3. Treat jaundice in newborns
4.Used to reveal different gas temperatures of objects in space
Short wavelength and short frequencies

13. Short wavelength and short frequencies
X-rays
Uses:
1. Shows broken bones, cavities, etc.
2. Airline security checks – see through bags
3. Hot gases in the universe also emit X-rays
Short wavelength and short frequencies

14. Shortest wavelength, highest energy = MOST dangerous
gamma waves
Uses:
1. Treat cancer
2. Kill organisms that spoil food
3. Doctor use gamma-ray imaging to see inside your body
Shortest wavelength, highest energy = MOST dangerous
4. Biggest gamma-ray generator is the Universe