roystgnr comments on For FAI: Is "Molecular Nanotechnology" putting our best foot forward? - Less Wrong

48 Post author: leplen 22 June 2013 04:44AM

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Comment author: roystgnr 22 June 2013 07:09:28PM 19 points [-]

a template of the sorts of things that are actually possible

Was this true at the macroscale too? The jet flying over my head says "no". Artificial designs can have different goals than living systems, and are not constrained by the need to evolve via a nearly-continuous path of incremental fitness improvements from abiogenesis-capable ancestor molecules, and this turned out to make a huge difference in what was possible.

I'm also skeptical about the extent of what may be possible, but your examples don't really add to that skepticism. Two examples (systems that evolved from random mutations don't have ECC to prevent random mutations; systems that evolved from aquatic origins do most of their work in aqueous solution) are actually reasons for expecting a wider range of possibilities in designed vs evolved systems; one (dynamic systems may not be statically stable) is true at the macroscale too, and one (genetic code is vastly less transparent than computer code) is a reason to expect MNT to involve very difficult problems, but not necessary a reason to expect very underwhelming solutions.

Comment author: CellBioGuy 24 June 2013 06:08:19AM *  6 points [-]

Biology didn't evolve to take advantage of ridiculously concentrated energy sources like fossil petroleum, or to major industrial infrastructure, two things that make jets possible. This is similar to some of the reasons I think that synthetic molecular technology will probably be capable of things that biology isn't, by taking advantage of say electricity as an energy source or one-off batch synthesis of stuff by bringing together systems that are not self-replicating from parts made separately.

In fact the analogy of a bird to a jet might be apt to describe the differences between what a synthetic system could do and what biological systems do now, due to them using different energy sources and non-self replicating components (though it might be a lot harder to brute-force such a change in quantitative performance by ridiculous application of huge amounts of energy at low efficiency).

I still suspect, however, that when you are looking at the sorts of reactions that can be done and patterns that can be made in quantities that matter as more than curiosities or rare expensive fragile demonstrations, you will be dealing with more statistical reactions than precise engineering and dynamic systems rather than static (at least during the building process) just because of the nature of matter at this scale.

edited for formatting

Comment author: ESRogs 24 June 2013 07:48:28AM *  1 point [-]

Please use paragraphs.

EDIT: thanks for the formatting update!

Comment author: OneBox 24 June 2013 05:26:30PM *  0 points [-]

What do you make of the picture Richard Jones paints ? I'm not much more than a lay man - though happen to know my way around medicine - find his critique of of Drexler's vision of nanotechnology sound.

Comment author: Pfft 24 June 2013 09:55:04PM *  1 point [-]

His position seems to be that Drexler-style nanotechnology is theoretically possible, but that developing it would be very difficult.

I do not think that Drexler’s alternative approach – based on mechanical devices made from rigid materials – fundamentally contradicts any physical laws, but I fear that its proponents underestimate the problems that certain features of the nanoworld will pose for it. The close tolerances that we take for granted in macroscopic engineering will be very difficult to achieve at the nano-scale because the machines will be shaken about so much by Brownian motion. Finding ways for surfaces to slide past each other without sticking together or feeling excessive friction is going to be difficult.

A hypothetical superintelligence might find it easier...

Comment author: OneBox 24 June 2013 10:36:39PM 0 points [-]

Yes, that seems to be is main argument against Drexler's vision, though I wonder if he thinks it's difficult to come up with a design that would be robust, or if the kind of nanotechnology would be difficult to implement since it requires certain conditions such as vacuum close to 0 kelvin, which might be a bit cumbersome even for a superintelligence(?) unless you hang out a lot in space.