[ExI] Fermi question, was is a FTL drive a dream . . .

[Eugen Leitl]

On Tue, Dec 20, 2011 at 12:46:40PM +0100, Stefano Vaj wrote:
> On 20 December 2011 01:22, Keith Henson <hkeithhenson at gmail.com> wrote:
> 
> > Perhaps.  But radio technology is not the only indicator of
> > intelligent processes.
> >
> 
> Yes, even though Wolfram's argument can be extended to any kind of
> signalling.

I presume Wolfram's argument is closely related to 
http://old.nabble.com/Everything-List-f18221.html

which have always struck me as a particularly sterile mode
of inquiry.

I have big problems which approaches attempting to
describe the physical universe in terms of a particular
view upon an infinity of... information stuff existing in some sort
of metaverse. This isn't provable as it explains everything
and nothing, and doesn't reduce the problem complexity but
actually increases it. It isn't turtles all the way down, no.

It's basically the same thing as the simulation argument, only
without a (bearded, elderly, white-clad male) entity doing a 
particular simulation for a particular purpose, and it's 
definitely not science.
 
> I do not really know how to resolve Fermi's paradox.

I fail to see where there is a paradoxon. Life is rare and
difficult to observe, why is this something surprising?
 
> The idea that we are the only, or the first, of something disturbs me
> aesthetically, as the all-too-easy recourse to the anthropic principle in
> cosmology and physics.

The universe doesn't care about what we consider aesthetical.
In absence of independent data points about life not causally
related to the local system we can't put any probability on
it that isn't pefectly biased. This is why probabilistic arguments
are not applicable, and observer-moments are bunk.
 
> What I tentatively find more persuasive is the idea that we might be too
> parochial in our view of extraterrestrial "life" or "intelligence". That
> is, we would recognise it only inasmuch as it is a slightly alterated
> version of ourselves; same as the AGIs being defined as a Turing-passing

No, it has to be subject to the laws of thermondynamics and evolution.
Anything which has a metabolism and self-replicates is easy enough
to observe.

> emulation. Now, if the space of all possible computations and/or darwinian
> processes is vast enough, we would be the "only ones" simply in the sense
> that it would be unlikely that two instantiations bump against each other
> that be similar enough for our purpose, unless they are deliberately
> programmed to this effect.
> 
> Moreover, I am not sure of how visible even civilisations and species
> pretty identical to ours could or would be making themselves on a cosmic
> scale. Let us say, eg, that somebody is making use of light sails and TW
> lasers the other side of Andromeda. Would it be an obvious, in-your-face,
> red drape for contemporary terrestrial astronomers?

Anything which can do interstellar travel would make you never have
happened. How can you observe something which prevented your very existance?
And if you expand at >0.9 c, which time will you have to observe
the stars blinking out across the galaxy before your own system 
goes splat? Evolution seems to take billions of years to create observers 
starting from congealed star drek, that either go extinct or give raise 
to expanding waves themselves, which will prevent any new observers from 
ever emerging when they've passed.

Given above, you shouldn't be wondering why you're not seeing them,
in fact what you're seeing is exactly what you expect you should be
seeing -- nothing.
 
> As to more massive footprints, I am a member of the Order of Cosmic
> Engineers, and I like Kardashev's speculations about Type III civilisations
> like the next guy, but the truth is that even a ton of mass is, well,
> heavy, and I would not take for granted that most clades quickly end up
> sculpting for fun the shape of neighbouring galaxies in the shape of their
> females... :-)

Their females look like ~AU-sized FIR sources with some few MT/s
total luminosity. Trust me on this.