[ExI] Silence in the sky—but why?

[BillK]

On Mon, Aug 26, 2013 at 3:53 PM, Eugen Leitl wrote:
> Any nonrelativistic expansion will be completely overgrown by
> relativistic expansion. As relativistic travel isn't hard (for
> small probes, anyway), this means you can consider nonrelativistic
> expansion an early, transient phase which is hard to observe.
> Unless you're the point of origin.
>

If a galaxy can be swarmed in 10 million years, then why haven't we
been invaded multiple times?
By non-relativistic *and* relativistic expansion.

> We're not talking about just single galaxies, but patches of
> real estate GLYrs across. Stellar systems would go dark very
> quickly, so by the time you see half of the sky going dark
> (FIR) your own system is already toast. Not a damn thing
> you can do about it, unless you're already expansive.
> So time interval from observer to expander is very short
> (few centuries in our case), and hence you need to be arbitarily
> unlucky in order to see half of the sky go dark.
>
> What we're seeing is exactly what we should be seeing.
>

No it isn't. That should have happened *billions* (not millions!) of
years ago, if it is going to happen at all.


>
> No, the entire visible universe would made from ~AU FIR blackbodies,
> but this is not something you could observe, as you would have never
> happened in the first place. As you're alive and observing, this
> indicates that we're not in anyone's smart lightcone.
>

But timescales say that should have happened long ago. We see the
whole universe from the early beginnings up to a few light years from
us and there is no sign of conversion to blackbodies anywhere, at any
stage of the universe growth. Our solar system is comparatively young
in the grand scheme of things.


>
> 'Intelligence' doesn't decide a damn thing, out of control and
> statistics decides everyting.
>

Now you're just being silly. I do believe interstellar travel and
eating the galaxy requires 'intelligence'. Not necessarily benevolent
intelligence, but you need a bit of IQ to build starships.

BillK