1. Properties of Light Light travels in straight lines called rays.
As we know, they are made up of transverse waves:
We also know that light is electromagnetic which means that it is made up of an electric and magnetic component.
Laser

2. Light can create shadows
Shadows are places where light is “blocked”:
Rays of light

3. What characteristics do light waves have?
Light waves are like other kinds of waves. They have crests, troughs, wavelength, frequency and speed. However, light waves are electromagnetic! Light waves have a component that is electric and magnetic!!

4. We see things because they reflect light into our eyes
We see things because they reflect light into our eyes! This is literally the only way we get to see things! ALL objects we see either create light or reflect light!!
Homework

5. Review-Electromagnetic Radiation
Travels at the speed of light
Is mostly invisible
Carries energy
Is made up of transverse waves of different frequencies and wavelengths.
Is VERY important to society and is something YOU can’t be without for many reasons

6. Types of electromagnetic radiation
Radio and TV - Great for broadcasting
Microwave-Super for cell phones, microwaves
Infrared-Think HEAT
Visible Light - Yep, it’s how we see
Ultraviolet - Invisible, can cause cancer; kills germs
Xray- images of bones and teeth; space exploration
Gamma - treating cancer (radiation therapy)

7. Reflection of Light
Smooth, shiny surfaces have an accurate reflection.
When light bounces off an object or surface, reflects!
It always reflects in the same angle that they hit the surface.
Materials that reflect light are called opaque.
Mirrors are opaque (don’t let light pass through)!

8. Transmission of Light
A material transmits light when it allows the light to pass through it.
Transparent materials permit almost permit almost all the light incoming light to pass through.
Transparent materials include glass, water and air.
Translucent materials scatter light when it passes through.
Translucent materials include wax paper, and frosted glass.

9. Refraction of Light
When light rays enter a new medium, they refract or bend.
This happens because the waves speed up or slow down when traveling in a different medium.

10. Example of Refraction Light rays are slowed down by the water
Causes the ruler to look bent at the surface
The mediums in this example are water and air

11. -White light will refract when it passes through a prism
-White light will refract when it passes through a prism. -This causes it to separate into its colors.

12. Lenses
Lens- a piece of transparent glass or plastic that has a curved surface.
-these curved surfaces refract light that pass through.
-the shape of the lens determines how it bends.
Concave- lenses that curve inward.
-light rays spread out.
Convex- lenses that curve outward. light rays
-light rays come together.

13. Absorption of Light Materials that absorb light are called opaque.
Light rays can be absorbed by an object and transmitted into heat energy.
Darker colors absorb more than lighter colors!

14. Color
White light is not a single color; it is made up of a mixture of the seven colors of the rainbow.
We can demonstrate this by splitting white light with a prism:
This is how rainbows are formed: sunlight is “split up” by raindrops.

15. How are colors created?
A red object reflects red light and absorbs much of the other colors.
The color of an object is that color which is reflected not absorbed.

16. Only red light is reflected
Seeing color
The color an object appears depends on the colors of light it reflects.
For example, a red book only reflects red light:
Homework
White
light
Only red light is reflected

17. The colors of the rainbow:
Red
Orange
Yellow
Green
Blue
Indigo
Violet
Just remember ROY G. BIV

18. In different colors of light this shirt would look different:
Red
light
Shirt looks red
Shorts look black
Shirt looks black
Blue
light
Shorts look blue

19. A white hat would reflect all seven colors:
A pair of purple trousers would reflect purple light (and red and blue, as purple is made up of red and blue):
Purple light
A white hat would reflect all seven colors:
White
light