non nanotech assemblers

John K Clark (johnkc@well.com)
Sun, 3 May 1998 21:41:05 -0700 (PDT)


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michet <christophe.delriviere@skynet.be> Wrote:

>Hi, first i will try to apologies for my bad english, it's basically
>because my mother tongue is french

Don't worry, your English is fine.

>I'm following this list since several months now and i'm rather
>surprised that only assemblers using nanotechnologies in their
>implementation are discussed here. Probably we could build a more
>"macroscopic" one. It will sure be less efficient than a
>nanotechnological one, but it's really worth to study too.


I think a macroscopic assembler is possible but it would not only be less
efficient than a Nanotechnology based one it would also be harder to make.
This topic was discussed on the list a year or two ago and I gave 6 reasons
to support my view.

1) The parts a macroscopic assembler uses would be very expensive, the parts
that Nanotechnology uses, atoms, are very cheap.

2) A macroscopic assembler must use many thousands or millions of different
types of parts and it must learn how to use all of them. At the most,
Nanotechnology uses 92 different parts (the elements) but in the real
world almost everything we know of is made of only about 20 parts, and for
life about 10.

3) All the many different parts a macroscopic assembler must use are fragile,
and fragile in different ways, the machine must learn the proper handling
techniques for them all or it will destroy the parts before it can use
them. There is no way you can damage the parts Nanotechnology deals with.

4) None of the parts in a macroscopic factory are absolutely identical.
Despite our best efforts, individual variation still exists, and so we
must deal with each part slightly differently and compensate for the
variation in the assembly process if we want the finished product to work
properly, that often takes intelligence. On the other hand, according to
the laws of Physics one hydrogen atom is absolutely identical to another
hydrogen atom and can be treated in exactly the same way. Atoms have no
scratches on them to tell them apart.

5) Nanotechnology can manipulate matter without ever leaving the digital
domain. You may have to deal with a rod 27 carbon atoms long, or 28 atoms
long, but you never have to worry about a rod 27.5601334 atoms long.
A Macro assembler wouldn't have that luxury when it tried to build
something with an oak log.

6) Most of the parts a macroscopic assembler use would have to be very
complex and the ways they interact with other macroscopic parts would be
even more complex. Think of the windshield of a car, it interacts poorly
with the engine block, and even with the windshield frame the interaction
must be managed with great skill or you'll have a disaster. Nanotechnology
is like building with Lego blocks, you can build structures of arbitrary
complexity, yet there are only a few different types of blocks and they
interact with other blocks in only a few different ways. It's easy to
develop an algorithm to examine any Lego object and then build a duplicate,
it's very far from easy to find an algorithm that would do the same with a
car.

John K Clark johnkc@well.com

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