Ed Walters speaks with Albert Einstein and mentions his theory of relativity. Einstein humbly says he too is still figuring out how his theories work.

Hank explains the role of the nucleus in a eukaryotic cell. He backs up his explanation with compelling visuals.

A brief lesson on the origin of mitochondria and symbiosis.

This clip explains how air intake while exercising pumps oxygen into the muscles which combines with ATP to create muscle contractions.

Bill Nye narrates the story of how photosynthesis was discovered. He explains the hypothesis of the experiment that shed light on how plants generate energy.