[extropy-chat] Dark matter and ET

[BillK]

From: BillK <pharos at gmail.com>
Date: Jul 17, 2005 11:13 PM
Subject: Re: [extropy-chat] Dark matter and ET


On 7/17/05, Eugen Leitl wrote:
> On Sun, Jul 17, 2005 at 07:04:15PM +0100, BillK wrote:
>
> > 'Light cone' ??? The diameter of the Milky Way is 160 thousand light
> > years. If any technological civ decides to colonise our galaxy, then
> > depending on the assumptions, it will only take from a few 100,000
> > years at c, up to a few million years to physically colonize the whole
> > Milky Way. This is a tiny, tiny portion of the lifetime of our galaxy.
>
> The light cone issue is relevant for 5-6 orders of magnitude larger scale.
> Nobody sees large spherical voids at supercluster scale. There might be
> isolated sightings of dark galaxies. I don't think they're brilliant, because
> it implies intergalactic void is a tough barrier to cross, which doesn't make
> sense.
>

Other galaxies are irrelevant. Estimates say the Milky Way has around
100 billion stars. That's 100,000,000,000. Maybe as many as 400
billion. Quite sufficient for my purposes, thank you.

Galaxies are usually millions of light years apart, with a few
well-known exceptions. Forget about other galaxies.


> > That is also one of the reasons I have for thinking that galaxy
> > colonisation is not an objective for post-singularity civs.
>
> You haven't given me any reasons, just said that it's as easy to blanket out
> a galaxy as it is a single star. I agree. You think they're not expansive, I
> think they're not there. Which explanation is simpler?


Actually I could agree with this. We *might* be the only, or first,
intelligent life in our galaxy. But we have a huge number of stars,
most much older than our sun. So I reckon the odds are against it.
Life seems to *want* to create itself in this universe.


> >
> > OK, so where are they?
>
> Again: we're not in anybody's smart light cone. There's nobody out there we
> can see yet. I pity poor presmarties in our light cone, though. They'll never
> know what'll hit them.
>

Again, light cones are irrelevant for our galaxy. Any expansive
post-singularity civ will relatively quickly be all over the galaxy.


> No. I told you you should see them on GYr scale (and in fact, if you could
> see them, you'd be dead soon after, or you'd never happened at all, which
> is a negative anthropic principle factor).

This is just a distraction. If the 100,000,000,000 stars in our galaxy
haven't produced an expansive civ to fill our galaxy, then I don't
care what might be going on in other galaxies. You are not increasing
the odds much by adding more galaxies, millions of light years away.


> Anything nonexpansive is irrelevant. Anything expansive you see for a
> gigalightyear distances.

That's the point! They are all nonexpansive in our galaxy, or they
would be all over us already.  Gigalightyear distances are
gigalightyears in the past (and irrelevant anyway).

>
> > intelligence) or
> > b) the singularity *always* kills civs, or
>
> What is the kill mechanism to reliably blanket a light day-month postbiology
> ecosystem, every time? I can't think of any. You can't recall the chain
> letter, that keeps on giving itself.
>

I hope you're correct here. :)


>
> I go we transcend now, and see for ourselves. My take is we initiate a
> relativistic expansive wave which will only get canceled by another one, or
> until dark energy sets an end to it.
>


If we did hit the singularity and decide to expand we would have
100,000,000,000 stars in our own galaxy to inspect shortly thereafter.
But I believe a transcendent civ will have *much* better things to do
than go on a centuries long plane trip.

BillK