11-17-2016, 08:34 AM
Cray has a point though. 3km of rock is insane, whether you're talking about particulate or electromagnetic radiation.
A GRB is a planet-sterilizing event in the long term, but at even moderate interstellar range it wouldn't be lethal in a single generation. It would take a while for the mutation load to build up faster than repair or selection could handle, for weak links in the biosphere to go extinct depriving others of food, etc. Eventually even the most shielded things would succumb, but not due to radiation; If they're shielded, they'd die out due to the crashing biosphere around them. The amount of radiation we're talking about at surface level is not compatible with life in the long run, but needing more than 10m of rock for shielding would imply the surface getting flash-fried.
A GRB is a planet-sterilizing event in the long term, but at even moderate interstellar range it wouldn't be lethal in a single generation. It would take a while for the mutation load to build up faster than repair or selection could handle, for weak links in the biosphere to go extinct depriving others of food, etc. Eventually even the most shielded things would succumb, but not due to radiation; If they're shielded, they'd die out due to the crashing biosphere around them. The amount of radiation we're talking about at surface level is not compatible with life in the long run, but needing more than 10m of rock for shielding would imply the surface getting flash-fried.