dduke@lll-crg.llnl.gov (David Allen Duke) (02/08/90)
I have been reading about nanotech in _Foresight Update_ in _EOC_, and a few other places. Maybe someone can answer (or tell me no answer exists to) the following questions: 1. Drexler makes the assemblers sound like a miniature robot with an arm to which is attached a molecule or an atom to be placed at a specific point. The mechanism proposed is "selective stickiness", but this does'nt sound any more usefull than chemistry. Is it? [I'll break my usual rule and answer these questions in-line: Atoms can be "stuck" with forces ranging from covalent bonds to van der Waals forces, with a difference in strength on the order of 100. The most desirable method would seem to be to "pick up" the reagent molecule with a van der Waals bond and have it have it latch onto the object you're building by a covalent bond, allowing you simply to pull the arm away and break the vdW bond by force. Alternatively, you might alter the geometry of the "gripper" to expel the reagent. Chemistry is like building a gadget of Lego blocks by alternately pouring piles of the various different kinds of blocks over the object. The trouble is they will stick everywhere it is possible for them to stick. Nanotechnology (like protein synthesis in the cell) is supposed to be a way to control which of the possible sites, a reaction actually happens at.] 2. Recent articles in _Foresight Update_ speculate about incredibly powerfull computer systems possible in an advanced nanotech society. I guess these speculations are based on the size and speed of imagined mechanical/molecular gate operations. Has anybody guessed what the difficulty would be of making mechanical gate ops interconnected, and how these gate ops would be powered? [As a computer architecture person myself, I've looked at it. The connectivity isn't a problem--remember that existing computers are basically planar; if you allow yourself 3 dimensions it's a lot easier. Power is a bit more out of my field, but suggestions tend to run to electrostatic motors of some kind. No one, by the way, seriously expects that nanocomputers will be actually built this way. Drexler holds them up as existence proofs; real nanocomputers will probably use highly involved quantum effects and run at speeds of about 100 terahertz instead of the roughly one megahertz the mechanical design could do.] 3. The closest thing to a nanomachine I've ever heard of is a virus. Has there been any attempt to alter an existing virus for a purpose? [No and yes. An assembler is not like a virus, since the virus requires an outside self-reproducing mechanism to work; to get going in nanotechnology you need to produce the self-reproducing mechanism itself. On the other hand, a virus might be like some specialized end-product of a different and larger nanotechnological base. And yes, retroviruses have been used to insert missing genes into organisms (I think, including humans).] In regards to discussions about cryonics on this newsgroup: In a technology advanced enough to literally raise you from the dead (frozen), I think the new limitation imposed on that society would simply be raw material. What will the motivation be for that future society to recover you? What will you offer? Should you sign an agreement before you die stating that you will abide by the laws of that future society? One final statement. If the promise of nanotech/AI becomes even partially true then it might be possible to subtly, yet directly alter mental state by altering synaptic wieghts and other aspects of brain function. I will wait for your responses before continuing.
shapard@manta.nosc.mil (Thomas D. Shapard) (02/09/90)
David Allen Duke writes: [skipping...other stuff, mostly covered by JoSH comments] >In regards to discussions about cryonics on this newsgroup: > >In a technology advanced enough to literally raise you from the dead >(frozen), I think the new limitation imposed on that society would simply >be raw material. True, but for the most part 'raw material' means plain dirt, nanotech being much less fussy about the macro from of raw materials than present technology is. And if you're worrying about running out of dirt, then there's the asteroid belt (as I recall Drexler suggested in EOC). > What will the motivation be for that future society to >recover you? What will you offer? Should you sign an agreement before >you die stating that you will abide by the laws of that future society? Pretend for the moment that some effective form of perservation has been in use for the last 200 yrs or so, and now, today, the technology comes on line to bring people back for, oh say $100K apiece (with the usual expectation of declining cost as time goes on and we learn more). Who would YOU like to bring back? How much would you contribute to bring back specific people, or to a research fund to bring the cost down further? If you're like me, you'd have a list of friends and relatives you'd like to see again, and you'd have a list of famous folks you'd like to see back again enough to contribute to the cause. In fact wouldn't it be an exciting time: people who in previous ages would have been lost forever actually returning, you - me - everyone getting to meet them, talk to them have them HERE again! The analogy with a future time, of n years from now, when the assumtions of technological ability come true is obvious. They will have personal personal interests in helping those preserved back to life. It's not a matter of some impersonal *society* deciding whether on not to bring people back, it's *people* deciding, wanting to bring other people back. There will certainly be problems for those returning (future shock in spades). But that's another topic. -- ''''''''''''''''''''''''''''''''''''''''' Tom Shapard shapard@nosc.mil NOSC, San Diego
alan@oz.nm.paradyne.com (Alan Lovejoy) (02/09/90)
In article <Feb.7.20.31.53.1990.4424@athos.rutgers.edu> well!dduke@lll-crg.llnl.gov (David Allen Duke) writes: >In regards to discussions about cryonics on this newsgroup: > >In a technology advanced enough to literally raise you from the dead >(frozen), I think the new limitation imposed on that society would simply >be raw material. What will the motivation be for that future society to >recover you? What will you offer? Should you sign an agreement before >you die stating that you will abide by the laws of that future society? Put yourself in the situation. You uncover a cryonically-preserved individual. You have the technology to revive this person. All you need do is order your nanomachines to start working, which costs you next to nothing. Will you revive this person? If you would not, would others? There are many people in the world who are driven to help others, even animals. Many do so quite altruistically: there's "nothing in it for them" other than psychic satisfaction. There is also an organization called Lifepact, which exists precisely to address the problem you raise. Lifepact is a mutual-aid society, whose members agree to revive and reorient each other. The idea is that in exchange for your own revival from cryonic suspension, you agree to provide the same service for someone else (once you are able). ____"Congress shall have the power to prohibit speech offensive to Congress"____ Alan Lovejoy; alan@pdn; 813-530-2211; AT&T Paradyne: 8550 Ulmerton, Largo, FL. Disclaimer: I do not speak for AT&T Paradyne. They do not speak for me. Mottos: << Many are cold, but few are frozen. >> << Frigido, ergo sum. >>
dennis@cpac.washington.edu (Dennis Gentry) (02/09/90)
From: well!dduke@lll-crg.llnl.gov (David Allen Duke)
Newsgroups: sci.nanotech
Keywords: gate operations, virus, mental state
Date: 8 Feb 90 01:31:54 GMT
2. Recent articles in _Foresight Update_ speculate about incredibly
powerfull computer systems possible in an advanced nanotech society. I
guess these speculations are based on the size and speed of imagined
mechanical/molecular gate operations. Has anybody guessed what the
difficulty would be of making mechanical gate ops interconnected, and
how these gate ops would be powered?
[As a computer architecture person myself, I've looked at it.
The connectivity isn't a problem--remember that existing computers
are basically planar; if you allow yourself 3 dimensions it's
a lot easier. Power is a bit more out of my field, but suggestions
tend to run to electrostatic motors of some kind.
No one, by the way, seriously expects that nanocomputers will be
actually built this way. Drexler holds them up as existence proofs;
real nanocomputers will probably use highly involved quantum effects
and run at speeds of about 100 terahertz instead of the roughly one
megahertz the mechanical design could do.]
Uh, doesn't the Drexler-designed rod logic gate switch in a few
picoseconds? Since current CMOS logic gates switch in a few
nanoseconds and current CMOS computer speeds are roughly 20-30
megahertz, wouldn't a rod logic computer (switching in a few
picoseconds) run at roughly 20-30 gigahertz? (rather than the
one megahertz you mention above).
As in electronic computers, the connections between each "layer"
of logic could be the same medium as the logic itself, i.e.,
carbine rods. Power is not difficult--rod logic can be
(synchronously) powered by some kind of oscillating rod, e.g., a
rod connected to a cam which is driven by a nano scale rotary
motor (which Drexler has also designed).
I think the hard part about these computers right now is
*building* them, not designing them. I believe I could easily
design a CPU using rod logic that would outperform any current
(single-processor) CPU by a factor of at least 10, if not 1000.
Or am I missing something in the question?
Dennis
[It depends on what you want to call "switch". The lock knob,
moving at 1000 m/s (speed of sound in carbyne) can move from
not blocking the probe knob to blocking it in a picosecond.
However, as mentioned, Eric designed the thing *very* conservatively,
since it is intended as an existence proof. Thus, the rods
are supposed to move at a small fraction of Mach 1, and wait
for vibrations to settle out, before the next cycle.
Consider implementing a macroscopic mechanical computer.
A 68000-scale machine with coat-hanger sized rods would be
at least a cubic foot. Can you build a 1kHz clock machine
in that technology? Speed of sound in steel would allow it,
but my intuition says that 10 Hz would be doing very well indeed.
Another thing to note is that real mechanical controllers are
almost never digital computers. They are generally special-
purpose devices, gaining orders of maginitude in efficiency
to the particular task. If nanocomputers are mechanical, my
bet is that a lot of them will be special purpose devices like
cams, linkages, Geneva mechanisms, etc.
--JoSH]