What is the difference between a theory and a law, and is one better? Matt Anticole shows why science needs both laws and theories to understand the whole picture. [5:12]

Imagine you are watching a runaway trolley barreling down the tracks.

Read about one of the greatest and most influential paleontologists of all time, George Gaylord Simpson.

Learn about German Physiologist, Theodor Schwann, one of the scientists who helped develop the cell theory.

"One of the great mysteries in science is the extinction of the dinosaurs at the end of the Mesozoic Era some 65 million years ago. Who (or more likely what) caused it is unknown and a subject of great debate." Many theories are touched...

Provides a long list of physics formulas for easy reference.