From: Anders Sandberg (asa@nada.kth.se)
Date: Tue Nov 26 2002 - 01:42:10 MST
On Mon, Nov 25, 2002 at 03:14:27PM -0800, Ramez Naam wrote:
>
> 3) Perhaps most problematically, in at least some proposals assemblers
> reproduce. This gets into an additional level of modeling and
> simulation which I haven't even mentioned up to this point.
> Essentially you start dealing with population biology, an area where
> modeling is now being applied but where our ability to predict exact
> outcomes is essentially zero.
The issue here seems to be levels of modelling. In computational
neuroscience we run into this all the time. We have good compartment
models that mimic real neurons pretty throughly, but take a long time to
run. So for large networks we instead use simplified neurons, where the
simplifications become more and more radical as we scale things up. The
important art here is to select the right level for the job, and the
right amount of simplification so that you can trust the result.
When designing a nanoassembler it seems unlikely that every part would
need to be simulated at the same degree. The casing hardly merits the
complexity of the tool tips, and population biology usually chunks
individuals into black boxes. There are always the possibility of some
unexpected miss in this approach (the free charge from a broken bond
moving into the casing, complex patterns of waste products around the
assembler interfering with the replication in a subtle way), but when
doing the initial design work it is more important to be able to
simulate the parts and whole of the system in reasonable time with
reasonable (but imperfect) accuracy to get the major design bugs out of
it. Once the design has converged, one can always do big high-precision
simulations to check it.
And if it turns out that everything depends on everything else,
requiring detailled simulation of every component to get the whole to
work, then the assembler design is too brittle and should be rejected as
flawed.
-- ----------------------------------------------------------------------- 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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