Jason Joel Thompson wrote:
> ----- Original Message -----
> From: "Nick Bostrom" <email@example.com>
> > >... Remember: no matter how small a fraction of all solar systems in our
> > >infinite universe develop life, we would by neccessity find that we
> > >(Earthlings and Martians) originate from one of the exceptional ones that
> > >did.
> > Yes, but it would not be necessary that we would have found ourselves> originating from a solar system where two civilizations had evolved
> > independently. That is the extra finding that would make all the
> > difference. If the evolution of intelligent life is very improbable then
> > would have been extremely unlikely that it would have happened on another
> > planet in our own solar system.
> No, you see, you're stuck measuring things on a plantary scale. Couldn't we
> instead surmise that our -solar system- was particularly good at creating
> life-bearing conditions?
Well, yes, but this would also imply that other solar systems like our own would
likely be as particularly good at creating life bearing conditions.
Now, Jeff Davis says:
> When I first read the article, I thought about it, and asked myself about
> the strongest signal would be--the signal which would give the greatest
> detectable range by which an affirmative conclusion might be drawn. I
> thought perhaps the EM pulse from a naked nuclear explosion would be
> both the strongest, as well as the signal most undeniably indicative of a
> technological civilization. Clearly, such a signal would be brief. But
> assuming that to be the best signature by which others might detect OUR
> presence, I did a little research into the amount of such 'signaling' that we
> have done. It turns out that in the period between 1945 and 1998 humans
> have conducted 2,050 nuclear explosions, of which 528 have been atmospheric,
> and 1522 undergound. If the EM pulse lasts for one tenth of a second (this
> is just a guess, I leave it to others to help out with something more
> that would mean 52.8 seconds of strong, unambiguous signal. Fifty-three
> seconds in fifty years. Using Arecibo's 10^14 watts as a basis of
> what might be the signal strength, and corresponding detection range for a
> nuclear explosion? Perhaps the answer should be given as a range,
> to the range of detonation yields?
However, excessive EMP signalling would not be an indicator of an intelligence
to communicate with, but either one to avoid or one that has exterminated
itself. Given 528 atmospheric explosions of nuclear weapons here on earth over
50 years, an alien race may conclude that we are a rather warlike and agressive
species that has little regard for its environment... not the sort of people you
would invite over for a visit... If we had had a nuclear war, we could become a
target of interstellar colonization, since they would then know our world was
capable of sustaining intelligent life, and that we were likely in a very weak
position following such a war to oppose colonization attempts by another race.
Use of nuclear weapons is likely a good means of signaling to agressive alien
species "Hey! Come conquer us!" because use of such weapons dates the level of
advancement of our species very accurately.
Because interstellar travel is so demanding energy wise (so far as we know) at
sub-light speeds, intelligent species likely cannot make an effective business
case for launching a mission to another planet in another star system unless it
can be shown that the planet can support intelligent life, and has a
technological infrastructure for the visiting species to hijack. Thus, they may
be out there, but they just listen for other races to off themselves with
This archive was generated by hypermail 2b30 : Mon May 28 2001 - 09:50:18 MDT