An Introduction to Spacetime Diagrams

Ever wondered why physicists talk about spacetime, rather than just space and time? This video is the first in a series to explain how Einstein’s concept of spacetime is more than just a funny word. In this video we focus on the concept of a worldline, which describes everything from objects just sitting there growing older to light beams traveling across the universe at the cosmic speed limit.

Check back in the Fall for a followup video using worldlines to show how falling apples and orbiting stars are both really doing the same thing: responding to curved spacetime that we interpret as gravity.

Special thanks to additional actors in this video not listed in the closing credits: Elizabeth Carlisle and James Mallon.