Re: >H Re: The Great Filter

Michael Lorrey (
Sun, 16 Mar 1997 13:56:44 -0500 wrote:
> (Paul Dietz) writes:
> >What *would* do it is the relativistic particles that are expelled
> >from the collision. These are thought to be the source of the gamma
> >burst (by folks building models of bursters at cosmic distances.)
> >These particles would carry much more energy than the gammas,
> >and would arrive over a period of centuries (since the particles
> >would not travel in straight lines, due to interstellar magnetic
> >fields.) They would induce radioactivity in the atmosphere and
> >produce secondary particles that would reach the ground.
> OK, this makes sense.
> Is a relatively (pardon the pun) nearby, but beyond the lethal radius (say
> 2000 light-years) neutron star binary collapse a plausible cause for mass
> extinctions?
> I would think that if such events are truly as common as this, the prognosis
> for long-term space colonization is poor. It would be very hard for a
> space-based civilization to sustain hundreds of years of hard radiation at
> such intensity that an atmosphere is insufficient shield. Even planetary
> based nanotech using civilizations would be very strained by such events.

It all depends on what you mean by long term, and how far in space you
plan on colonizing. Considering that we are talking about astronomical
events which happen once every several hundred million years, I would
say that the odds give us a good sized window to get out of harms way.

That technicium levels in molybdenum deposits indicate the existence of
such gamma ray bursters in our own geological past (supposedly the late
cretaceous), or that our sun was once eight times as bright as it is now
at that point in time (not bloody likely) indicates that this is a
phenomenon that we can outrace given sufficient technology. Once we've
expanded past the limit of possible extinction, then any such
catastrophe thereafter is simply a stumble in our march across the
skies. Once it happens, we've got 100-200 million more years to rebuild
and expand further. Besides this, I expect that technology will allow
the development of sheilding sufficient to protect any "Noah's Ark" type
preserves, possibly in the cores of asteroids or dead moons like our
own. Several hundred miles of solid rock in every direction should be
enough sheilding against anything two neutron stars can cook up from
several hundred light years away.


Michael Lorrey ------------------------------------------------------------ President Northstar Technologies Agent Inventor of the Lorrey Drive

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