Section 1, Lecture 1

What is Light & Color?

The Electromagnetic Spectrum is a term scientists use when they want to talk about radiating energy—radiation. All radiation is carried by photons, which are massless particles that travel at the speed of light. These photons can have greater or lesser amounts of energy.

White light is made out of all the colors of the rainbow. When white light passes through a prism, we can see it spread out on the other side into its different colored components. Red, green, and blue are colors of light that aren’t a mixture of any of the others. We call them primary colors. Colors like yellow (a mixture of red and green light) are known as secondary colors.

An object is a particular color because of the color of the light it reflects.

Electromagnetic Spectrum