Any thoughts on seeming lack of Exterestrial Contacts?

Gieljan de Vries wrote:

 > Well, before a star can become a neutron star, it has to go supernova
 > first.
 > This alone destroys the ozone-layer of earthlike planets up to 200 ly
 > away.
 > Anything the pulsar's radiation can do after *that* is icing on the
 > cake o'
 > death.

The theory the original poster was referring to is that neutron
star-neutron star collisions might be responsible for gamma ray
bursters, events far more energetic than supernovae. It was
hypothesized that neutron star-neutron star collision could occur with
rates that would essentially keep a galaxy sterilized for astronomical
timescales, and only now would their frequency have decreased so that
only now could intelligence have formed. This was highly speculative
since it depends on the neutron star population and the circumstances
under which those binary systems would form, the precise frequency
distribution of collisions and how it changes over time, and the power
and anisotropy of the explosions themselves caused by the collisions.

The theory wasn't given a tremendous amount of weight in the first
place; it was highly speculative. The leading explanation for the cause
of gamma ray bursters today is hypernovae, which are extremely powerful
supernova type events which form a black hole in a certain way such that
two enormously powerful but narrow jets of radiation are emitted along
the axis of rotation of the progenitor. If you're in those jets, you
see a gamma ray burster.

--
__ Erik Max Francis && max DeleteThis @alcyone.com && <a style='text-decoration: underline;' href="http://www.alcyone.com/max/" target="_blank">http://www.alcyone.com/max/</a>
/ \ San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis
\__/ I like young girls. Their stories are shorter.
-- Thomas McGuane<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Any thoughts on seeming lack of Exterestrial Contacts? 

Erik Max Francis <max.RemoveThis@alcyone.com> wrote in message news:<410E7321.340554E.RemoveThis@alcyone.com>...
 > Gieljan de Vries wrote:
 >
  > > Well, before a star can become a neutron star, it has to go supernova
  > > first.
  > > This alone destroys the ozone-layer of earthlike planets up to 200 ly
  > > away.
  > > Anything the pulsar's radiation can do after *that* is icing on the
  > > cake o'
  > > death.
 >
 > The theory the original poster was referring to is that neutron
 > star-neutron star collisions might be responsible for gamma ray
 > bursters, events far more energetic than supernovae. It was
 > hypothesized that neutron star-neutron star collision could occur with
 > rates that would essentially keep a galaxy sterilized for astronomical
 > timescales, and only now would their frequency have decreased so that
 > only now could intelligence have formed. This was highly speculative
 > since it depends on the neutron star population and the circumstances
 > under which those binary systems would form, the precise frequency
 > distribution of collisions and how it changes over time, and the power
 > and anisotropy of the explosions themselves caused by the collisions.

Ah. That wasn't clear to me from the post's text; I got the impression
the OP was referring to pulsars /per se/. Thanks for clarifying.

Best regards,
Gieljan<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Any thoughts on seeming lack of Exterestrial Contacts? 

Gieljan de Vries wrote:

 > Erik Max Francis <max.DeleteThis@alcyone.com> wrote in message news:<410E7321.340554E.DeleteThis@alcyone.com>...
 >
  >>Gieljan de Vries wrote:
  >>
  >>
   >>>Well, before a star can become a neutron star, it has to go supernova
   >>>first.
   >>>This alone destroys the ozone-layer of earthlike planets up to 200 ly
   >>>away.
   >>>Anything the pulsar's radiation can do after *that* is icing on the
   >>>cake o'
   >>>death.
  >>
  >>The theory the original poster was referring to is that neutron
  >>star-neutron star collisions might be responsible for gamma ray
  >>bursters, events far more energetic than supernovae. It was
  >>hypothesized that neutron star-neutron star collision could occur with
  >>rates that would essentially keep a galaxy sterilized for astronomical
  >>timescales, and only now would their frequency have decreased so that
  >>only now could intelligence have formed. This was highly speculative
  >>since it depends on the neutron star population and the circumstances
  >>under which those binary systems would form, the precise frequency
  >>distribution of collisions and how it changes over time, and the power
  >>and anisotropy of the explosions themselves caused by the collisions.
 >
 >
 > Ah. That wasn't clear to me from the post's text; I got the impression
 > the OP was referring to pulsars /per se/. Thanks for clarifying.
 >
 > Best regards,
 > Gieljan


Nope, it's the later that was in an article I was reading. Very
memorable was the description of the two jets sweeping across the
region, fatefully scorching the planets of life.


Sorry for the mix up, I'll see if I can Google up a reference link...
(It helps if I spell Extraterrestrial correctly also.)

Ah, here is a thread discussing a disturbingly likely candidate and
some of the issues.


TBerk<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Any thoughts on seeming lack of Exterestrial Contacts? 

T wrote:

 > Ah, here is a thread discussing a disturbingly likely candidate and some
 > of the issues.
 >
 >
 > TBerk
 >

Sorry.

<http://www.sciforums.com/forumdisplay.php?f=6><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Any thoughts on seeming lack of Exterestrial Contacts?