Stephen Colbert Learned All About Supernovas and Broke a Guinness World Record

About 3.8 billion years ago, a star erupted in the most powerful supernova explosion we've ever seen. 

Theoretical physicist Brian Greene recently appeared on The Late Show With Stephen Colbert to explain just how astonishingly powerful this supernova explosion was — and beat a Guinness World Record in the process. 

How a supernova works: Stars run on nuclear fusion, but eventually they run out of fuel. A supernova happens when a star reaches the end of its life and it doesn't have any more material left to power the nuclear fusion happening in its core. 

When the fuel runs out, the star collapses in on itself and then rebounds in a powerful explosion.

It's hard to imagine how powerful this is, so Greene and Colbert had a handy demonstration. It's called a Galilean cannon. The large ball at the bottom represents the star's core, while the smallest ball represents the star's surface. 

So when a star explodes, a shockwave ripples through the different layers and ejects the last layer in a powerful explosion:

This was the tallest Galilean cannon ever demonstrated, so Greene is now the proud holder of a Guinness World Record.