2. What is light?
Light is a type of energy that travels as a transverse wave.
It is also known as Electromagnetic Radiation.

3. Electromagnetic Waves
Light is an Electromagnetic Wave because it can travel through empty space or matter.
Electromagnetic waves consist of changing electric and magnetic fields.

4. Producing EM Waves
Electromagnetic waves are produced by the vibration of an electrically charged particle.
The transfer of energy as electromagnetic waves is called radiation.

5. The Speed of Light
Scientists have yet to discover anything that travels faster than the speed of light.
The speed of light is about 300,000,000 m/s
This is roughly 670,616,629 miles per hour or 186,000 miles per second
If you ran at the speed of light, you could travel around Earth 7.5 times in 1 second!

6. Light and Mediums
Light is not a mechanical wave, meaning it DOES NOT require a medium.
This is why we can see the light from stars that are millions of miles away.
Even though EM waves do not need to travel through matter, they can travel through many substances.
EM waves travel at slightly slower speeds through different materials, such as air and glass.

7. Our Light Source
It takes about 8.3 minutes for light to travel from the sun to Earth.
This is because Earth is 150,000,000 km from the sun.

8. The Sun’s Energy
The EM waves from the sun are the major source of energy on Earth.
Plants use photosynthesis from the sun, and animals use and store that energy after eating those plants.
Because the sun gives off EM waves in all directions, very little of it actually reaches Earth.
Most of the sun’s energy travels out into space.

9. Electromagnetic Spectrum
All EM waves travel at the same speed in a vacuum.
We then have to determine the differences in the types of waves by using wavelength and frequency.
The entire range of EM waves is called The Electromagnetic Spectrum.

10. Electromagnetic Spectrum

11. Electromagnetic Spectrum
The spectrum from long to short wavelength is:
Radio waves
Microwaves
Infrared Waves
Visible light
Ultraviolet Light
X-rays
Gamma rays

12. Textbook Information
Turn to page 66 in the Holt Science and Technology: Sound and Light book
Read pages Use your guided notes to write information about each type of EM wave. Then, answer questions 1-12 on lined paper.