Re: The Extinction Challenge
Sun, 1 Aug 1999 17:21:22 -0700

John Clark, <>, writes:
> >Billy
> >Yes, I do. If you think I'm wrong, show me the error in my calculations.
> I don't need to check the calculations of your theory, I know you're wrong
> because it doesn't fit the facts. As I already said, the 1987 supernova event
> produced about 20 neutrinos in one second that were detectable in one of
> our primitive neutrino observatories, and it was not close, it was in another
> galaxy.

Earlier Billy wrote:

: A typical supernova would have a total energy output of something like 
: 10^44 ergs.  Applying a little basic geometry, that gives us an energy 
: density of 2x10^10 ergs per square meter at a distance of 100 million 
: kilometers, which will certainly do a lot of damage.  However, at a 
: distance of 1 light-year (9x10^12 kilometers), the energy density drops to 
: less than one erg per square meter.

I think there may be a math error here. The area of a sphere 1 light-year in diameter is is 4 pi r^2 or 10^33 square meters. If energy of 10^44 ergs is spread out over that area it implies 10^11 ergs per square meter, not < 1 erg per square meter.

Also, in a blurb about gamma ray bursters at I find:

} Gamma-ray bursts have recently been confirmed as the most energetic 
} explosions ever observed with ~10^53 ergs of energy (100 times the 
} energy of a supernova) and released predominantly in gamma-rays of 
} energy >50 keV.

If 10^53 ergs is 100 times the energy of a supernova then a supernova would put out 10^51 ergs, greater than Billy's starting figure by a factor of 10 million, and leading to an estimate of 10^18 ergs per square meter at 1 light-year.