Re: Limits and Capabilities.

From: Eugen Leitl (
Date: Thu Jun 13 2002 - 08:38:51 MDT

On Wed, 12 Jun 2002, Michael Roy Ames wrote:

> IMO, the overwhelming limiting factor soon to face humans will be the
> speed of light. It *already* limits the speed of CPUs, and as we

No it doesn't. You just have to put your bits where your logic is.
(Despite proven nonlocality physical processes are intrinsically locally
coupled, since an event can't influence others lying outside its light
cone, so it's not that much of a limitation -- unless your life processes
are not based on something as exotic as, say, recursive wormholing).If
your switches are single molecules operating on bits stored in adjacent
molecules the shortest switch time will have to be above the time it takes
light to cross the volume. (You don't want your switches to radiate
light). In practice, even with reversible logic you will run into power
dissipation issues way before. (Of course, fractal cooling channels with a
high flux of coolant dilute your circuitry, increasing average distances).

Also hitherto I regarded stable strangelets as science fiction, but
apparently some theories do allow them, and a couple of people even
postulated a corellated twin tremor as a strangelet clump passage through
Earth (maybe they should limit their crack intake). Depending on their
properties they might be useful for very small, very hot computers (e.g.
mechanical ones driven by nuclear processes, e.g. fusion). Bootstrap
issues loom large once again, though, since even if you can mine the stuff
floating between the stars it doesn't mean you can process it (what's
Young's modulus of strangletronium?).

> advance, this limitation will become more and more... annoying. I
> observe there are *already* increasing resources being devoted to
> probing this limit, with intent of bypassing it. As time passes I

We can intent all we want, we still can't do jack if the universe doesn't
let us.

> strongly suspect we will exert ever increasing 'pressure' on this
> limit, and, if it is possible to bypass it, we *will* do so. If that
> occurs, our current limits will seem rather... pedestrian.

Indeed, since superluminal velocities are equivalent to time travel, and
likely would require spacetime plumbing.

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