From: Anders Sandberg (asa@nada.kth.se)
Date: Tue Jun 18 2002 - 03:15:09 MDT
On Tue, Jun 18, 2002 at 12:06:27AM -0400, Brian Atkins wrote:
>
> You're missing my point, which is that something as "super-smart" and "super-
> fast" as you were talking about should be able to make the VR realistic
> enough (hence my use of the word "emulate") to completely do any needed
> testing in that arena. Or do you believe uploading is impossible? The
> same level of emulation capabilities are required in either case- if it
> can do one it can do the other it would seem?
I run across people from time to time who think that since I spend my
time studying simulated brains instead for real brains, we could do away
with all animal experiments and use simulations instead. It doesn't
work, since to make a good simulation you need the data of the
experiments. Even if we had simulations so good that they seemed just
like the real thing, how can we be sure they really depict the real
thing and not just something close but subtly different? I certainly
can't tell a rat with or without a 10% dopamine deficiency from each
other, but if the results of my simulation hinged on this fact they
would be different.
When is a simulation an emulation? When *every* detail in the real
system has a counterpart in the emulation. A simulation is a
simplification, either due to lack of data, lack of knowledge of the
real system, for efficiency or due to lack of resources. Even
superintelligences have to deal with this: they can't just apriori
deduce all physical laws, they have to do empirical work to discover
them and that always leaves room for surprises; the emulation of the
entire Earth would require some kind of scanning that interacted with
every atom in the planet - which in itself is close to the kind of
potentially devastating tech we are discussing the deployment of in the
first place; computronium isn't arbitrarily cheap, and to *emulate* the
Earth you would need a computronium system of comparable mass. So it
doesn't seem that an emulation is feasible.
Simulations are just arguments in the form of "given these assumptions
and initial conditions, X will happen". You can run validation by
changing assumptions and initial conditions, which is good, but you
won't get certainty. A good simulation will give you a small uncertainty
and help convince you and others that a risk may be worth taking, but it
is still not an empirical argument. Physics is constantly throwing upp
weird effects that doesn't show up in simulations, even in apparently
well understood areas **. If you start testing genesis machines based
solely on simulations, please warn me beforehand so that I can flee the
area. It is just the recipe of a Hollywood disaster.
** A fun example I heard of last week: equally sized beads of two
different plastic types form a regular checkerbord pattern when shaken
on a gold surface. Apparently some form of triboelectricity results, but
simulations have so far failed since the charge distribution is not
simply a lattice of point charges but something more complicated.
-- ----------------------------------------------------------------------- Anders Sandberg Towards Ascension! asa@nada.kth.se http://www.nada.kth.se/~asa/ GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y
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