Is light a particle or a wave? Or both? Or neither? Learn how humans have defined light throughout history -- including our best attempts today -- in this classic episode of BrainStuff.

BrainStuff Classics: How Did Alchemy Create Chemistry?
07:11

How Did Sundown Towns Say the Quiet Part Out Loud?
11:35

Why Do We Yawn, and Why Is It Catching?
12:02