See what I’m saying?

What Is Light?
 Electromagnetic Wave (EM): a wave that travels through matter or space and consists of electric and magnetic fields
Field: area around an object that can exert a force, push, or pull on another object
No contact is needed

Electromagnetic Wave (EM)
Electric Field
Magnetic Field

How Is Light Produced?
 The vibration of an electrically charged particle!!!!
FILAMENT
Radiation: emission of energy in the form of EM waves
When electrical energy is supplied, the atoms in the filament vibrate back and forth

The Production Of Light
Step 1 All electrons can be found in an energy level
When they absorb energy…

The Production Of Light
Step 2 Electrons cannot stay at these levels
When they fall, they release energy…

The Production Of Light
Step 3
Electrons continue to move back and forth, creating a stream of photons

Speed Of Light

In a vacuum…300,000,000 m/s
However, light travels slower in air, glass, and other types of matter
1.27 Seconds
382,000,000 m

Light Interactions
4 Interactions of Light

Reflection
 When light or any other waves bounces off an object
Allows us to see objects that do not produce their own light

Diffuse Reflection
When light waves reflect at many different angles!!

Absorption and Scattering
 Absorption: the transfer of energy carried by light waves to particles of matter
 Scattering: the release of light energy by particles of matter that have absorbed energy

You See What I’m Saying?
To see things, we can use lenses…but how many are there?

Convex Lenses
As the light enters to the left, the lens bends or refracts the light to a single
“focal point” where all the light meets at once

Concave Lenses
As the light enters to the left, the lens bends or refracts the light outward at different angles

Refraction
 Bending of a wave as it passes at an angle from one medium to another

Light and Color
 Color is produced by REFLECTION and ABSORPTION!!!!
The colors that are
REFLECTED are the colors that you can see!!!!!!

What Are Our Basic Colors?
Meet ROY G. BIV
 THE RAINBOW!!!
R
O
Y
G
B
I
V
= RED
= ORANGE
= YELLOW
= GREEN
= BLUE
= INDIGO
= VIOLET