Great line in this one: [...]The physicist who mentioned this problem to me told me his rule of thumb for estimating supernova-related numbers: However big you

Great line in this one: [...]The physicist who mentioned this problem to me told me his rule of thumb for estimating supernova-related numbers: However big you think supernovae are, they're bigger than that. Here's a question to give you a sense of scale: Which of the following would be brighter, in terms of the amount of energy delivered to your retina: 1. A supernova, seen from as far away as the Sun is from the Earth, or 2. The detonation of a hydrogen bomb pressed against your eyeball? Applying the physicist rule of thumb suggests that the supernova is brighter. And indeed, it is ... by nine orders of magnitude.