A Supernova only 640 Light years away from us could mean wed be in for a very bad day. . . X-ray radiation would be high. . . Not good. Depends on how bad that nova is. Brightness that close, followed by a wave of slower particles will not be good for anything that close.
Good thing I am a proponent of the Electric/Plasma Universe which does not follow the claim that Super Novas actually occur. They are electrical in nature and merely flares caused by changes in electrical potential. Still could be bad for X-ray radiation.
If you want on or off the Electric Universe/Plasma Ping List, Freepmail me.
Alfvén postulated that the universe has always existed [10][11] due to causality arguments and the rejection of ex nihilo models, such as the Big Bang, as a stealth form of creationism.[12][13]Smaller matter/antimatter collisions at the boundaries account for the redshift evidence of an expanding universe? That's really out there as a concept. See what I did there?