How Do We Measure How Big the Universe Is?

Since the time of the ancient Greeks, scientists have been constructing a cosmic measuring tape to measure the universe from our own backyard all the way to its ever-expanding edge: the cosmic distance ladder. In this video, we climb that ladder and explore how each rung has revealed something new and previously unthinkable about the universe we live in.

0:00 How far away are things?
1:05 Near, far, parallax that star
3:25 Island universes and Hubble's blinking star
5:51 Redshifted rainbows and the expanding universe
7:41 Supernovae and the end of everything
9:08 Conclusion: The ladder of discovery
10:00 I'm hosting a game show!