>
> In a message dated 8/29/97 8:17:17 AM, bostrom@mail.ndirect.co.uk (Nicholas
> Bostrom) wrote:
> >There is a difference between the three systems you mention, on the
> >one hand, and nano self-replicator on the other. Mycoplasma
> >genitalium, automotive vehicles and comersial software are all
> >required to be fairly optimized.
>
> No, none of those are "optimized". Insofar as they are optimized, germs and
> commercial software are heavily optimized for miniumum design requirements,
> even at the cost of performance.
(Fairly optimised). Germs are highly optimised, given
certain design constraints, shaped as they are by immense selection
pressure and short generation cycles. Cars are optimised. Much
commersial software is also fairly optimised. But you have a point
here. There is also commersial software whose performance is not
optimized, and in some cases it can still it can be highly
non-trivial to design it. So if that is the relevant analogy then it
points in the direction Carl intended it to.
> >To build an optimised nano
> >self-reproducing device would be much harder than simply to make
> >something useful that can replicate. For example, a universal Turing
> >machine has been constructed in Conway's Life world. The entity is
> >very big and it was hard, but nothing near a thousands of genius-year
> >task, to do it.
>
> Nobody has presented a self-replicating Life system. All Conway did was
> produce a feasibility proof, so you know it *can* be done. Actually
> designing such a system is still considered not yet possible.
Really? I thought I've heard that the Universal Turing machine was
actually designed, with streams of gliders serving as tape etc. But I
may be wrong, in which case I'm glad you pointed it out. Do you have
any references?
>[some interesting intuitions contrary to mine omitted]
Nicholas Bostrom
http://www.hedweb.com/nickb