Re: poly: Fermi Paradox and Smolin's selected universes

[[ mail at cco failed for a while. Re-sending. -- Damien S. ]]

Robin Hanson wrote:

> Damien B. responds to Hal who responded to Peter:
> >>If life works to prevent the formation of black holes that would otherwise
> >>have formed, then universes in which life evolves will have fewer
> >>offspring than universes in which it does not (unless life also triggers
> >>the formation of more baby universes than would otherwise happen)
> >
> >If life choses to tweak black hole formation to raise the likelihood of
> >life-congenial baby universes, a kind of meta-cosmic gardening,* while
> >cutting back the overall number of black holes (to use the stellar material
> >for other purposes), presumably a huge range of equilibria is possible.
>
> An interesting topic.

> ...
> Second, if life wanted to gain max negentropy, it would eventually want to
> create the biggest holes possible, as black hole entropy goes as the square
> of the mass. The best way to do might be to make small holes then merge
> them.

If you have the time and inclination, a multi-billion solar mass black hole can
be
constructed from a galaxy without expending very much energy. Consider e.g.
the Milky Way as a trillon+ body problem, counting brown dwarfs, etc. A survey
and
computation of future positions and velocities has to be made first. Then
simulations
of alternative future distributions can be run and selected for minimal net
required power
input (this is not a trivial calculation), with "what if" velocity changes in
some small
percentage of the bodies. A very small change made now can evolve into a very
large departure from the natural future state.
The idea is to cause multiple encounters between the bodies. At most such
encounters, one
body gains energy (relative to the galactic center), the other loses, and moves
closer in.

Very roughly one half of the galactic mass can be diverted into the black hole,
the
other half, in the form of rogue stars, is sent out of the system. The ratios
are highly
dependent on 'dark matter' distribution or whatever it is that causes galaxies
to
depart from inverse-square gravitation.

The longer the time scale you are willing to work at, the less energy need to be

put into course corrections- up to a point. At some point the power expenditure
for computation exceeds that for velocity changes imposed on the system.
Interstellar
gas clouds also add complicated terms to the multi-body problem. At the height
of
collapse a Seyfert or quasar is lit, adding a radiation pressure term as well.

> But how many baby universes are made by holes that get merged,
> as many as the holes you started with, or as the holes you end up with?

A good question.

Forrest

--
Forrest Bishop
Manager,
Interworld Productions, LLC
Chairman,
Institute of Atomic-Scale Engineering
http://www.speakeasy.org/~forrestb