What do we know about light?

Light and Color

Properties of Light

Light travels in straight paths:

Laser

Light travels VERY FAST-around 300,000 kilometers per second.

At this speed it can go around the world 8 times in one second.

Light travels much faster than sound.

Thunder and lightning

start at the same time,

but we will see the lightning

first.

• We see things because they reflect light into our eyes:

Homework

Transparent

Light passes through objects in varying amounts.

Opaque

Translucent

What happens when light hits an object?

Light refracts.

What color is reflected? Does the color seem to change where it is when the light moves?

Pigment or Iridescence?

Fabric Square #1

Fabric Square #2

Fabric Square #3

CD

Feather #1

Feather #2

Black Square

CD micro- structure

Peacock FeatherMicro-lamellae

• Reflection from a mirror:

Incident ray

Normal

Reflected ray

Angle of incidence

Angle of reflection

Mirror

Law of Reflection 

When a ray of light is reflected from asmooth surface, the angle of reflection

is equal to the angle of incidence.

Normal Line

Credit to Rory Gates 10 years old