We humans are fairly squishy, and we eat fairly squishy food. So how do we grow hard bones? Learn how it happens in this classic episode of BrainStuff.

American Versus British English: What Are Biscuits, Muffins, and Pudding?
09:51

How Do Sunspots Work?
14:22

Did the Lost Continent of Lemuria Really Exist?
11:05