Light is everywhere in our world. We need it to see: it carries information from the world to our eyes and brains. Seeing colors and shapes is second nature to us, yet light is a perplexing phenomenon when we study it more closely.

Here are some things to think about:

  • Our brains and eyes act together to make extraordinary things happen in perception. Movies are sequences of still pictures. Magazine pictures are arrays of dots.
  • Light acts like particles—little light bullets—that stream from the source. This explains how shadows work.
  • Light also acts like waves—ripples in space—instead of bullets. This explains how rainbows work. In fact, light is both. This “wave-particle duality” is one of the most confusing—and wonderful—principles of physics.

Scientists have spent lifetimes developing consistent physical, biological, chemical, and mathematical explanations for these principles. But we can start on the road to deeper understanding without all the equations by acting as scientists do: making observations, performing experiments, and testing our conjectures against what we see.

The activities in this lab are designed to give you ideas about light—and also about how you can use technology to explore light. Collectively, the activities are a sampler—rather than comprehensive demonstration—of these two topics:

  • Light in Color. Color is more than decoration, and perceiving color is tricky. Three activities help you see how colors interact and how we can use color as a scientific tool.
  • Laws of Light. Light behaves according to special rules; for example, it usually travels in a straight line and it bounces off mirrors at the same angle it hits them.