From: Adrian Tymes (wingcat@pacbell.net)
Date: Fri Aug 15 2003 - 16:18:31 MDT
--- John K Clark <jonkc@att.net> wrote:
> "Christian Weisgerber" <naddy@mips.inka.de> Wrote:
> > 1. The effects of gamma irradition drop with
> the distance.
>
> Not all forms of radiation decrease according to the
> inverse square law,
> Laser beams don't.
Laser beams do diffuse according to inverse exponent
after a certain distance. Don't recall the numbers
well enough just now to say if that exponent is 2,
but any laser beam has at least minimal divergence.
One can focus this divergence inwards, so the light
comes to a point at some distance out, but after that
distance, it's spreading. One can also try to narrow
the divergence - indeed, one of the main useful
properties of lasers is that their divergence is so
small as to be practically zero over very long
distances. But if you shone just about any modern
laser towards, say, Pluto, the beam would probably
have measurably diverged by the time it got there.
(Maybe just barely measurably, but still measurably.)
> > As far as I know, traditional fission and
> fusion devices release
> > most of their energy in the form of gamma rays
>
> No, it's X rays. mostly soft X rays.
From http://www.wikipedia.org/wiki/Atomic_bomb :
> When a nuclear weapon explodes, the bomb's material
> comes to an equilibrium temperature in about a
> microsecond. At this time about 75% of the energy is
> emitted as primary thermal radiation, mostly soft
> X-rays. Almost all of the rest of the energy is
> kinetic energy in rapidly-moving weapon debris.
Then again, gamma rays in small quantities can still
do great damage compared to similar amounts of thermal
or kinetic energy, especially when one focuses on
which form of energy will still be around an hour
later.
This archive was generated by hypermail 2.1.5 : Fri Aug 15 2003 - 16:33:34 MDT