[ExI] Fermi Paradox and GRB bursts

[BillK]

On Thu, Oct 2, 2014 at 10:06 AM, Anders Sandberg wrote:
> Yes, I have read the paper and still remain unconvinced. Destroy the ozone
> layer and the land biosphere is in trouble. But do you really think that
> will wipe out fish all the way to the bottom of the Marianas trench? Their
> conclusion is not compatible with other papers on GRB damage I have read.
>
>

I think the authors of the paper would agree with you. I don't see
them claiming total life extinction from a GRB. Though if food chains
are destroyed, the extinction could be very extensive.

What they are saying is that nearer the galaxy centre there are more
frequent GRBs such that intelligent life will never have time to
arise. A GRB is a knock-back of billions of years in life evolution.

Other papers have suggested that some early extinctions on Earth might
have been due to GRBs.

I think their paper is reducing the area of the galaxy where
intelligent life might get the time to develop. i.e. SETI shouldn't
look near galactic centre for intelligent life.

BillK