Re: Engineering Phase Spaces, was: Plasma engine calculator

From: Michael Lorrey (
Date: Thu Mar 22 2001 - 08:43:34 MST

Okay, I now have xlsim-gurus set up as a mail list on sourceforge for
project discussions. I also invite everyone interested in registering
with sourceforge as a developer to join the project.

"Robert J. Bradbury" wrote:
> On Thu, 22 Mar 2001 wrote:
> > How many thermo-nuclear fusion reactors are powering cities?
> > Zero. And the funny thing is, it might take one of Yudkovsky's Super
> > Intelligences to finally develop a working model, if the aren't busy doing
> > other things.
> Its interesting to wonder if the problem with TNF is that it
> fell victim to Moore's Law? The 19th and early part of the
> 20th centuries, the dreams were always "bigger" and "larger"
> (you only have to look at the Saturn C designs or some of
> the Russian N-1 or UR-family rocket designs to see that).
> But one of the consequences of the Apollo program was the
> push for miniaturization that led to the development of the IC
> which was the real foundation for Moore's Law. Once we had
> that in place, our enchantment with "bigger" got replaced
> with "smaller". Since smaller requires less material, its
> inherently cheaper. So you shift to pursue this exploration
> of the engineering phase space until it bottoms out, presumably
> with full blown single-atom nanotechnology. Once you have
> that, exploring the phase space of "bigger" gets much cheaper.
> Now, one of the problems with TNF, was that the primary
> concept was the Tokomak (or variants thereof). This is
> inherently a large scale device (and therefore expensive).
> They have had to keep scaling this back because the public
> and governments don't want to spend the money to build
> something this large. It will be very interesting to
> see over the long term how small we will actually be
> able to make TNF reactors. If you take some of the
> ion driven inertial confinement approaches (I think
> Berkeley is working on these for example), combined
> with nanoscale ion accelerators (right up against the
> limits of the laws of physics in terms of acceleration
> over distance), I'll bet you can get TNF for a lot lower
> mass/power ratio than the Tokomaks. The problem with
> the Tokomak and the National Ignition Facility is that
> they require such a large amount of matter to create
> the energy densities to drive a fusion reaction.
> It is worth noting that the NIF, since its using ~10 year
> old concepts and the construction is proving quite problematic
> will quite likely be obsolete by the time it is finished.
> Diode laser technology is moving ahead at a very fast paceu
> (the NIF is powered by flash lamps of all things...)
> Yet another sign of the singularity -- any "big" technology
> instantiation you build is guaranteed to be obsolete by the
> time it is finally complete.
> Robert

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