What Is Light?

Lesson Plan - Get It!

Audio:

Shine a flashlight at a solid surface. Look at the light that is projected.

• What do you see?
• What do you think light is?
• Where do you think it comes from?

Light is essential to human life! You wouldn't be able to do much if you lived in complete darkness, but light is so much more than just the opposite of the dark.

Simply stated, light is energy. Light can be a natural energy source, such as the sun, or it can be an artificial energy source, such as the energy produced by the battery in a flashlight.

Energy travels in waves. The lights and colors you see are your brain's perception of energy. If you were able to see each wave of energy that came from the sun or a flashlight, you would see hundreds or thousands of waves.

Since energy travels in waves, light has properties of a wave. You will learn more about light waves in the next of the Related Lessons, found in the right-hand sidebar.

Light also has properties of a particle. Scientists call these particles photons, light particles made of electromagnetic energy. To learn more, read photon.

It can be difficult to explain what a photon is. Create your own definition for photon, based on the passage you read.

All scientists agree that light is energy, but many still disagree about whether light is a wave or a particle.

Continue on to the Got It? section to learn more about this scientific debate.