Re: neutron stars and what ever

[Tompaleo@aol.com]

In a message dated 96-01-26 21:35:25 EST, you write:

>A neutron star could cause havoc with land and sky animals if it were close
>enough and aligned so we were in the stream of neutrons.  However the water
>would quickly decrease the number and energy level of the incoming neutrons
>so that they would not be a problem to life. The water borne life would not
>have been effected anywhere as much as the land animals. As they both took
it
>on the chin somewhat evenly this mode of extinction is also unlikly. In
>addition the neutrons decay in a very short time and so there might not be
>anythat really got here in the first place.


Hi Paul,

Not being pickey here but,

Slight problem here. Neutron stars _do_not_ emit neutrons. There are composed
of them! In fact, it is believed that a neutron star becomes so because the
collapsing star does not have the mass needed to become a black hole. I
believe that is ~3 solar masses. So instead, the intense gravitational
collapse forces the individual atoms so close togerther that neutrons are
formed! This is kind of the reverse of neutron decay: Basically,

n >>> e +p + antineutrino

A neutron star is then the result of

p + e + intense gravitational collapse  >>> n +E

where p= proton, n= neutron and e= electron, E= energy in various forms

A second problem arises due to the half life of _free_ neutrons, about 636
sec (10 mi.) Since neutrons travelling through space would not be travelling
at the speed of light,  it would take longer to reach earth than even for
neutrinos. Assuming some intense neutron event occurred,  the event woould
have to accurred very, very close to the earth because in 10 minutes only
half of the neutrons emitted would still be left. Again, the only candidate
for such an event would be novae, supernovae, gamma ray bursters and similar
high energy events and we as well as the rest of the solar system would be
vaporized at that distance!

A man made analogue is the _ neutron bomb_. It is basically a fusion bomb
that is designed to fizzle out (in nuclear terms) . A low yield fission bomb
is used just as in H- Bombs but without the tampering needed to keep the
fission-fusion components together long enough to sustain fusion.  It is
heavily doped with U238 to enhance the flux of fast fission neutrons which
escape the bomb as a burst of high energy neutrons and zap people. Little
structural damage to cities is caused. H-Bombs themselves also emit high
levels of neutrons even when things go normally. That is the main problem
with experimental fusion reactors as well. 

Finally, any such burst of  neutrons that made it to the atmosphere, in still
detrimnetal numbers,  would cause a whole suite of atmospheric reactions that
should cause increases in radiogenic molecules that would in turn emit all
kinds of radiation that would ostensibly toast everything on the surface!
Similar reactions occur today in the upper atmosphere but with cosmic rays
(high energy protns) from the sun and beyond but luckily on smaller scales .
A familiar product is the formation of C14.

Regards,
Thomas R. Lipka
Paleontological/Geological Studies