White Light

How is white light made?


If several colors are shined together , then white light is made.


3 Flashlights

Red, blue, and green cellophane

White wall


Light is electromagnetic radiation that we can see. Light is made up of wavelengths. The color red has a wavelength of .00007 cm. Violet has a wavelength of .00004 cm. Light travels at the speed of light. The speed of light is 299,792,458 meters per second or 186,282 miles per second.

Oracle Thinkquest Education Foundation. (1999). Discovering Light: The Physics of light. Retrieved from http://library.thinkquest.org/27356/p_index.htm

White light is a mixture of all colors.

Skipor, Ph.D., Andrew. (1999). Ask a Scientist: DOE Office of Science, Measuring white light. Retrieved from http://www.newton.dep.anl.gov/askasci/phy99/phy99523.htm

This experiment idea was found in the book "Cool Science Experiment." It was written and tested by teachers and illustrated by Glen Singleton.


I placed one flashlight with blue cellophane, one flashlight with green cellophane, and one flashlight with red cellophane shining on a white wall. I took pictures of each flashlight one by one. Then I took a picture with all flashlights shining in one spot.


The blue cellophane shined blue on the wall. The green cellophane shined green on the wall. The red cellophane shined red on the wall. When I shined all three together in the same spot, the colors turned to white.


I learned that a red light shines red, a blue light shines blue, and a green light shines green. But, when I combined all three lights, the lights shined white together.

My hypothesis was correct. If several colors are shined together, then white light is made. My experiment supported my research.