Bringing the Universe to America's Classrooms
Explore How Light Is Needed to See Things

What If There Is No Light?

Look at this picture.

  • Where is there light?
  • Where is there no light?
  • Why does it matter if there is light?
A dark, rocky underground cave has light streaming in from a small opening at its far end.
Areas inside the cave that are in the path of light are visible. The edges of the picture and areas that are out of the path of light are dark.

Click on Visualize It.

Produced by