Tuesday, September 18, 2007

History Channel: Mega Disasters: Gamma Ray Burst

The History Channel aired this one hour film ("Mega Disasters: Gamma Ray Bursts") on Sept. 18, 2007. Gamma ray bursts appear to come from supernovas or hypernovas (mostly in young galaxies) (long type) or when neutron stars collide (short type), as may happen sometimes in our own Milky Way. Because GMB's are flares in specific directions (as from a lighthouse) most of them are unnoticed. It appears that earth may have had a mass extinction 450 million years ago from a GMB.

GMB's close enough to damage early (< 10000 light years) probably occur only every few hundred million years, but there is no way to predict when another one could occur. If it did, there would be a bright blinding flash, and the gamma rays would cause the various nitrogen oxides to form in the stratosphere, wiping away half of the ozone layer, causing a brown smog and acid rain and a "nuclear winter" leading to mass starvation of 90% of the world's population. There would be an EMP effect destroying electronics, and the nighttime sky would be green with auroras.

Fortunately, this catastrophic event seems to be extremely rare, compared to other disasters. It sounds like it could make a Screen Gems movie.

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