What’s brighter?

Randall Munroe, creator of the awesome web comic xkcd, has a knack for putting things in perspective. I really enjoyed one of his “What If” questions regarding supernovae.

Which of the following would be brighter, in terms of the amount of energy delivered to your retina:

A supernova, seen from as far away as the Sun is from the Earth, or

The detonation of a hydrogen bomb pressed against your eyeball?

Answer? The supernova is brighter… by nine orders of magnitude.

Wow. Astrophysics is so cool.