RE: The Extinction Challenge

From: Billy Brown (ewbrownv@mindspring.com)
Date: Wed Jul 28 1999 - 15:45:16 MDT


John Clark [SMTP:jonkc@worldnet.att.net] wrote:
> No need to conjure up exotic stuff like Hypernova's or Gamma Ray
Bursters,
> 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
would
> 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
ewbrownv@mindspring.com



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