Mega-mega engineering? 2

Twink (
Thu, 27 Nov 1997 19:30:48 -0500 (EST)

At 10:56 AM 11/27/97 +0100, Anders Sandberg <> wrote:
>> Let's say the universe is closed. Is there any way we can make it
>> open? I was thinking about reconfiguring the mass in it. (As you
>> already know, I tend to side with the open universe side.)
>Fun that you ask, I regularly ask how we could close an open universe :-)


>I have so far not heard a good suggestion in this area, there are
>unfortunately too few experts on global relativity on this list. I
>think there is a theorem somewhere, mentioned in Tipler's Physics of
>Immortality, that says it is not possible to open a closed universe.
>This is a rebuttal to Freeman Dyson's proposal in his paper "Time
>Without End" where he wonders if this is possible:
> I only raise one question which may offer us a thin chance of
> survival. Supposing that we discover the universe to be
> naturally closed and doomed to collapse, is it conceivable
> that by intelligent intervention, converting matter into
> radiation and causing energy to flow purposefully on a cosmic
> scale, we could break open a closed universe and change the
> topology of space-time so that only a part of it would
> collapse and another part of it would expand forever? I do
> not know the answer to this question. If it turns out that the
> universe is closed, we shall still have about 10^10 years to
> explore the possibility of a technological fix that would
> burst it open.
>I think the basic problem is the topology change; general relativity
>doesn't allow the drastic change in topology from S^3 x [0:1] to
>R^4. However, all is not lost since there are plenty of people who
>study how topology change could occur in quantum gravity. It it can
>occur, at least we might be able to make basement universes that are
>open or closed depending on our cosmological preferences.

I'm not sure either. Of course, as Dyson noted, we have time -- and as
I am inclined to believe, the universe may very well be open anyway.

There might be other things involved to. Perhaps, on a global scale,
we are not limited to topological changes... For instance, perhaps
(and someone else has raised this possibility; so I make no claims to
originality here:) we can "tear" off a region in such a way as to
achieve just what Dyson was after.

Another intriguing possibility in an open universe is that entropy and
order can both increase -- in absolute NOT relative amounts.:) This
is Layzer's idea. He might be wrong, but we should see if there's
anything to his idea.

Daniel Ust