[ExI] extropy-chat Digest, Vol 98, Issue 14

[Keith Henson]

On Fri, Nov 11, 2011 at 5:00 AM,   BillK <pharos at gmail.com> wrote:

> I like this paper. It explains how human (and all life) expands into
> unpopulated areas.
>
> But it stops at space.

Right now the only thing stopping humans from going into space is the
low state of technology.

Humans were stopped by water for ten of thousands of years from
spreading into the Americas.

As some of you know, I have been working on beamed energy propulsion
for a number of years.  A recent development is finding a way to get
into space starting with an airdrop that takes a mass ratio 2 and
ground based 20 GW of beamed energy to support a half million ton per
year SBSP construction project.  It's tricky because of the limited
time (~220 s) the vehicle is in view of the ground station.  The
effective exhaust velocity is almost 20 km/s.

But in the slightly longer run, the beamed energy source will itself
be in space.  Because of the longer acceleration time you get from a
space source, the power can be reduced to 5 GW or less, or the flight
rate increased.

In any case, there seems to be a physically realistic method to reduce
the cost of getting into space by 1000.  That's only one order of
magnitude from Freeman Dyson's estimate that the cost was 10,000 times
too high.

snip

> But advanced civilisation is the opposite of breeding like rabbits.
> Evolutionary expansion no longer applies. They *choose* their
> environment and build it to suit themselves. They *choose* how many
> progeny they want to create and for what purpose. If they have
> thousand-year lifespans they will probably create very few offspring.

I suspect they will live practically forever and have *no* offspring at all.

Along that line, it seems to me humans could be extinct by the
definition of "a breeding population" before the end of this century.
That probably closes off space for good.  Speed of light delays might
limit people to the planet if they can't stand to be more than so many
nanoseconds from the center of things.  People are already spending
hundreds of millions of dollars to chop off a few ms from the New York
to London fiber path.

> The idea of creating millions of entities and firing them off to
> colonise the universe is an insane waste of resources originating in
> primitive human evolutionary drives.

Unless humans are alone in our light cone, something like this happens
universally, i.e., we see no expanding civilizations out there.

Keith