There are a few people in the history of physics who have made insights that have revolutionized our understanding of the interactions of math and physics and given us real insights into the meaning of our theories. Don Lincoln tells us of the tale of Emmy Noether – one of the most significant geniuses of the last century.

Two cars, heading toward one another head-on at a velocity, have a closing velocity of twice that velocity. But at very high speeds, this intuition of adding velocities wrong. In this 9-minute video, Don Lincoln explains how to add velocities in a relativistic environment.

Relativity has many mind-bending consequences, but one of the weirdest is the idea that objects in motion get shorter. Bizarre or not, Don Lincoln explains just how it works in this 11-minute video.

As a child, Kirsty Duffy learned about the smallest building blocks that make up the world and was inspired to pursue physics through high school and college. She talks not only about self-doubt in one’s abilities, but the thrill of making a discovery and being the one to share it with the world.