VISIBLE LIGHT AND

COLOR

WHAT IS LIGHT?Light arrives on our planet from the

Sun, (93 million miles away).

Light travels at

186,000 miles per second, so the light you're seeing now was emitted from

the Sun about eight minutes ago.

Remember: Light does NOT need a medium to travel through!

Sunlight is not light of just one color—it's what we call white light, made up

of all the different colors mixed together. Rainbows appear when light

from the sun is refracted (bent) by droplets of water.

When white light is refracted through a prism, you can also see

the spectrum of colors.

We see different colors because light energy travels in the form of waves.

The color red has the longest

wavelength.

Purple has the shortest

wavelength.

Colors appear differently because they travel with different

wavelengths.

Visible Light Spectrum: ROYGBIV(Red, Orange, Yellow, Green, Blue,

Indigo, Violet)

1. What does ROYGBIV stand for?

2. Which color in the visible light spectrum has the shortest wavelength?

3. Which color in the visible light spectrum has the lowest frequency?

Quick Check!

Purple

Red, Orange, Yellow, Green, Blue, Indigo, Violet

Lowest frequency/Longest wavelength: RED

Color is one of the strangest things about light. We see things because sunlight (white light) is reflected off them. So why isn’t everything the

same color?

When light hits an object it can be • Reflected• Absorbed• Transmitted

The color of an object depends on the color it reflects.

Why does a tomato look red? When sunlight shines on a tomato, the red

part of the sunlight (that wavelength) is reflected back again off the

tomato's skin, while all the other colors of lights are absorbed (soaked

into) the tomato, so you don't see them.

That's also true of a blue book, which reflects only the blue part of sunlight but absorbs light of other

colors.

Why is the sky blue? Sunlight reaches Earth's atmosphere

and is scattered in all directions by all the gases and particles in the air. Blue light is scattered in all directions by the tiny molecules of air in Earth's

atmosphere.

Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a

blue sky most of the time.

There are other types of waves that we cannot see. These waves are too

long or short to be visible to us. Notice there is a very small area of the spectrum that is visible light.

Visible Light• Transparent Materials–

materials that transmit most of the light through them.• Light passes through easily• Example: glass, saran wrap,

water, etc.

• Translucent Materials– materials that scatter light through them as the light passes through. • Light is blurred• Example: cloud

Visible Light• Opaque materials– materials that reflect

or absorb all of the light that passes through them. Opaque materials are the color they reflect.• Light is blocked• Example: aluminum foil, cardboard, etc.

Let’s experiment!• I have 3 different objects.• Predict what will happen when I

shine a light…• On the 1st object• On the 2nd object• On the 3rd object

• Observe what actually happens…