RE: The Extinction Challenge

Billy Brown (
Wed, 28 Jul 1999 16:45:16 -0500

John Clark [] wrote:
> No need to conjure up exotic stuff like Hypernova's or Gamma Ray
> just a garden variety supernova would probably do the trick if it were
close enough.
> Neutrino are normally harmless but the flux from one of these monsters
> be so incredibly enormous all life would probably be sterilize within a
few dozen cubic
> light years. The other unpleasant aspects of a supernova could be
shielded against but
> not neutrinos, it's hopeless, you're fried.

A classic suggestion. However, interstellar space is more than big enough to provide protection.

A typical supernova would have a total energy output of something like 10^44 ergs. Applying a little basic geometry, that gives us an energy density of 2x10^10 ergs per square meter at a distance of 100 million kilometers, which will certainly do a lot of damage. However, at a distance of 1 light-year (9x10^12 kilometers), the energy density drops to less than one erg per square meter. That isn't even enough energy to damage electronics, let alone harm people. Conclusion: Despite their reputation, supernovae are only dangerous to people in the same solar system. They certainly aren't a threat to interstellar civilizations.
Billy Brown, MCSE+I