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Nanotechnology: Are Molecular Assemblers Possible?
Roland Piquepaille writes "Two experts in the field of nanotechnology, K. Eric Drexler, Ph.D., cofounder of the Foresight Institute in Palo Alto, Calif., and the person who coined the term "nanotechnology," and Richard E. Smalley, Ph.D., a professor at Rice University and winner of the 1996 Nobel Prize in Chemistry, exchanged open letters about "molecular assemblers" -- devices capable of positioning atoms and molecules for precisely defined reactions in almost any environment. These letters are making the -- long -- cover story of the current issue of Chemical & Engineering News. At the end of this rich exchange of four letters, they still disagree about the issue. Drexler thinks "molecular assemblers" are possible while Smalley denies it. Who is right? Don't count on me to give an answer. This summary contains some forceful quotes from the original letters."
Also interesting is Ray Kurzweil's comments on the exchange:
/ ar ticles/art0604.html
http://www.kurzweilai.net/meme/frame.html?main=
84-page peer-reviewed white paper on nanofactory. Conclusion: we see no hurdles, predicted time line: 10 years from now we could haave the first operating assembler... http://www.jetpress.org/volume13/Nanofactory.htm
You're the one who doesn't know what he was talking about. He literally described using machine tools to make 1/2-size versions of themselves, then using those ones to make 1/2-size versions of them, and so on. He then argued about the scale down to which you could do that.
For a good book check out The Computational Beauty of Nature). Some tasks can be broken down into very simple repeated actions which simple machines can perform. The beauty of these system is that they require little communication between agents. Merely an awareness of what is around you and a simple list of tasks can create some complecated forms.
Granted. Feynman theorized that it could be done. He made a $1000 bet to his students that they could not construct a working motor 1/64 of an inch square -- He lost this months later when a student was able to produce it. Feynman was disappointed because he figured that the technology needed to get construction down to the molecular level would have sprung forth from his little grassroots project. This is where Drexler and Feynman differ.
The main difference between Feynman and Drexler, (and why Drexler deserves to have an equal share of the limelight) is Drexler is a more responsible scientist.
I highly recommend you stop on over to the Foresight Institute website [foresight.org] and see what Eric Drexler has been responsibly been working on for the past 20 years. There's an online version of Engines of Creation [foresight.org] available in which Drexler examines the hopes and dreams of Nanotech, minus the onesided utopia/distopian slant. Drexler has always been an advocate for technology to be developed by responsible hands (whoever that is) and asks Should We? as well as Could We?
I think this novel humanitarian approach to groundbreaking scientific development is a bit refreshing, don't you?
Chris McAllister=Cheers! Chris McAllister
If you just read the exchange of letters, well, it does appear that Drexler does not properly address some of Smalley's points. Drexler points out that "fingers" are not needed, that there are other mechanisms for guiding the molecules to their reaction point. But he never elaborates on what these mechanisms are, nor addresses Smalley's issue about molecular reactions not being as simple as assembling Lego bricks.
I suppose if I finished reading my copy of Drexler's Nanosystems, I'd see more information about proposed methods of directing molecules and getting the desired reactions, but it's still not there in these letters.
Smalley is making one hell of a claim though, going from criticizing Drexler for not having clearly articulated (to his satisfaction) the methods of molecular assembly, to claiming that molecular assemblers are impossible. As Drexler points out with the quote from Smalley - when a scientist claims something is impossible, they are more than likely incorrect.
I understand Smalley's perspective, by trying to dissuade fears of runaway nanomachines and the like - but that doesn't mean Drexler's idea is wrong, but that the idiots that assume any nanomachine invented will instantly start replicating itself and turning the planet into grey goo. There's a higher likelihood of humanity being wiped out by a meteor impact, nuclear war, or the appearance of a super-virus than the grey goo occuring.
"You know your god is man-made when he hates all the same people you do."
A while back, Sean Morgan did the most interesting work I've seen on a timeline and prerequisites for Nanotechnology. At present, odds are that we'll see an assember sometime around 2022.
From the exchange, Drexler gives the impression that matter at the atomic scale behaves in the same way as matter on the macroscopic scale that we live in.
Physicists and chemists would know that this assumption is false. The Dalton theory of atoms as billiard balls has been refuted a long time ago.
How is a mechanical manipulator going to "grab" another atom? These manipulators are also at the atomic scale! Duh.
Today near the bottom of the http://www.foresight.org/ website, it shows a unrealistic graphic of one of Drexler's proposed nanofactories. There are what appears to be spherical atoms being manipulated by machinery. -- It fails to accurately show that the machinery is no more solid than the lego atoms that the machinery is manipulating. (Unless maybe the machinery material is made of some sort of selectively reactive/nonreactive, subatomic material)
When I see pictures & notions like that being bandied about and sold to the public, I get the same feeling when people push Jules Verne's voyage to the moon as science rather than science fiction. -- Baloney.
Right now Smalley wins. He's a doer, an implementer.
Drexler may get the last laugh in the far future, but some real science must appear first to make science fiction a reality.
The really hard stuff is in the implementation. The implementers deserver the real credit.