Re: [PLUG] "Nearby"

[JP Vossen <jp@jpsdomain.org>]

On 03/02/2017 04:08 PM, Walt Mankowski wrote:
> This is getting more and more off-topic

And that's relevant here *how* now?
<ducks>


> On Thu, Mar 02, 2017 at 03:49:18PM -0500, Rich Kulawiec wrote:
...
> > The Drake equation is an attempt to enumerate the probabilistic factors
> > that go into an estimate of the number of civilizations in our galaxy.
> > (Let's pause to ask ourselves if the number on this planet is 1 or 0.)

Even if it is >=1, there may be arguments that humans don't count.  _So 
long and thanks for all the fish_ and all...  Without taking sides, I'd 
factor in all of American politics & politicians as about a -1,000.

...
> > Having been in a few of those bar arguments with other physicists,
> > all of whom were much better qualified than I am to be participating,
> > my fallback position is what I call the Kulawiec hypothesis (hey, it's mine
> > -- get your own!) which is that our best chance of detecting a *former*
> > intelligent civilization will be the electromagnetic emissions generated when
> > they annihilate themselves in a planetary thermonuclear exchange.  This is
> > the interstellar equivalent of "HELLO OUT THERE!...errr...ummm...goodbye."
> > Of course if they do themselves in via other means (destroying their
> > planet's ecosystem, mass drivers, epidemic, Nicki Minaj) then they
> > may pass without our knowledge.

There's a related question which I'm totally unqualified to even 
consider, but yet, I will.  The electromagnetic radiation (EMR) that 
Earth emits is an expanding spherical shell.  It started when we started 
emitting, and is subject to attenuation per the cube/square law.  How 
much longer are we going to emit like that?  Broadcast radio & TV are, 
at least arguably, declining.  A lot of internet is in glass fibers that 
don't emit much or any EMR into space.  But there may be lots of other 
things emitting EMR I'm not thinking about.  So--how much longer are we 
going to be emitting at detectable levels?

Now, extrapolate that out with whatever Drake variables you want.  If we 
assume other civilizations follow a similar pattern, then for us to 
detect them via emitted EMR (not the only means, but the 
biggest/easiest, I think), then we have to intersect their expanding EMR 
shell before it attenuates to background noise, *and* while they are 
still emitting it!  That means they have to be:
* Pretty close or
* Really loud for
* A really long time and they
* Probably had to start a while ago 'cause light-speed and our detectors 
and stuff

Now of course, all of this ignores those civilizations that go out of 
their way to broadcast, "hey, we're here, come eat us and steal our 
water!" or who like to create warp emissions just outside the atmosphere 
(Z. Cochran I'm looking at you).  Or...the Kulawiec hypothesis...

:-)
JP
--  -------------------------------------------------------------------
JP Vossen, CISSP | http://www.jpsdomain.org/ | http://bashcookbook.com/
___________________________________________________________________________
Philadelphia Linux Users Group         --        http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion  --   http://lists.phillylinux.org/mailman/listinfo/plug