From: Robert J. Bradbury (bradbury@aeiveos.com)
Date: Wed Jan 09 2002 - 23:18:30 MST
On Wed, 9 Jan 2002 Entropyfoe@aol.com wrote:
> John K Clark wrote
> "I don't see how Gamma ray Bursters could explain the Fermi paradox.
> A burst only lasts a few seconds so half of the planet would be
> shielded by 8000 miles of rock. There would be survivors."
>
> Yea, I thought the same thing, gammas are absorbed by meters of rock and iron
> etc, so why would it torch everything? They implied in their graphic that
> the atmosphere would all be ionized, perhaps around the globe.... someone
> has modeled this?
Go read the daXn paper. I think its only come across the list
3 times at this point.
The gamma rays, which I think are put out spherically only
cause severe damage to "nearby" planets -- and you are right
the shielding would help on the far side of the planet.
Its the cosmic ray "jets" that pack a larger effective radiation
dose and arrive over a much longer period (so the planets get
fully irradiated as they rotate into the "wind") that are the
*real* problem. As their radiation dose is higher they harm
planets further away -- but because they are directional
they only harm systems in directly in their path.
Robert
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