From: hal@finney.org
Date: Sun Aug 01 1999 - 18:21:22 MDT
John Clark, <jonkc@worldnet.att.net>, 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
http://www.physics.mines.edu/news_and_events/dingusabs.htm 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.
Hal
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