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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."
If, in the future, copying physical objects is nearly as easy as copying information on a computer, will corporations lobby to pass laws that make it illegal to do so? In other words, will I be arrested one day for making a copy of my friend's Ferrari?
Richard Feynman talked about nanotechnology way back in 1959--before "nanotechnology" was even a word.
It kind of irks me that the person who coins a word gets more credit than a person who talked about the actual process--nearly thirty years prior.
Read Feynman's talk at the Zyvex Web site.
Also interesting is Ray Kurzweil's comments on the exchange:
/ ar ticles/art0604.html
http://www.kurzweilai.net/meme/frame.html?main=
How long would it take one of these assemblers to make a cup of "Tea, Earl Grey, Hot"?
Trolling is a art,
In lectures and in a September 2001 article in Scientific American, Smalley outlined his scientific objections to the idea of molecular assemblers, specifically what he called the "fat fingers problem" and the "sticky fingers problem."
/.ers have had to face at one point or another.
Aye, this is something that almost all
From reading the letters I don't think Drexler has really addressed the problems raised by Smalley fingers at all, he just tries to brush the problems aside.
Panurge has posted for the last time. Thanks for the positive moderations.
So there, Smalley wins, he got scared children into the debate. Only thing likely to win debates better are beautiful women's tears, knockout punches, and defaulting by just leaving the room in a huff.
Conversion Rate Optimisation French / English consultant
Try to make a C compiler out of C while you are at it. Oh yeah...Already done!
If I had to bet, I'd say that Drexler was right. Smalley seems to rely on strawman arguments (they'd be restricted to water) and arguments from incredulity (the fat fingers schtick). This is the same sort of plausible sounding arguments that have been used to "prove" (in my lifetime) that we will never detect planets around other stars, that we will never be able to image individual atoms, that I will never have a hi-res colour display on my desk, that we will never be able to clone a mammal, etc., etc.
If you strip away the fancy words (and shamelessly simplify), this becomes much more obvious:
Drexler may well be optimistic about the timeline, and may well be underestimating the difficulties, but I've yet to see an argument that it can't be done that holds up under critical examination.-- MarkusQ
Your body does what you've described all the time using DNA as the storage device, and only a two-part complex to do the actual assembly (ribosomes). One problem is, there we're talking about assembling from a fairly well defined set of components which are themselves complex enough to have ways of being selective (an amino acid of a particular geometry will bind preferably to a particular other structure). When you're talking about single atoms, there isn't that much of a geometric factor acting in your benefit anymore. Of course, we even manage that somewhat, since there are particular proteins in our body which end up having a single metal ion of some type or other in the center of them (hemoglobin - iron, chlorophyll - magnesium). The question is, can we generalize this and make it externally controllable (i.e. we feed the DNA-equivalent in by some remote process that preferably doesn't involve changing the environment we're building in).
In the body, communication is usually done diffusing some chemical species that the other cells react to. So perhaps there'd be a byproduct of what one robot is building, and the others would be designed to be able to detect that byproduct to measure the local status. You should be able to build fairly complex uniform structures just knowing the local environment (periodic structures like crystals or networks), but it'd be difficult to build a single highly specified structure unless you used some other control mechanism with good spatial resolution, like in chip manufacture.
Yes, they are possible. Look at what living cells already do ... every single one of them. They convert raw materials into cell structures. We already know it's possible; we just need to figure it out how to do it our way, or copy the way the cells do it.
Cyde Weys Musings - Scrutinizing the inscrutable
By your logic we don't exist. After all, how could a human have been born without a human to bear it?
;) ).
But good job on restating the chicken and egg problem in an obscure way.
The first molecular assembler can be built "by hand", just like the first robots were. We've already got the capability to shove around individual atoms (remember IBM spelling out "IBM" with Xenon atoms?), so it's at least theoretically possible (as long as we only need Xenon atoms to build it at least
No offense, but what idiot thought to use 2.4ghz inside the body?
Yes, of course it barely transmits, 2.4ghz is the frequency used by microwaves to heat food, because water absorbs it so well.
Hint: We're mostly water too.
Now if we could just dessicate people utterly, those transmitters would work just fine...wouldn't be much of a life monitor, though...
--Dan
What we have here are two different worlds colliding. Drexler is coming at this from the point of view of a theoretical physicist, while Smalley is an experimental chemist.
Drexler has found certain theoretical processes which would lead to molecular assemblers. The key problem comes from his assumption of complete control over the atoms. Despite his assurances to the contrary, you still have one big fat sticky finger which you've attached your strained structure to. He simply sees that it is possible (of course, if you read his books, there is a glaring lack of chemical calculations).
Experimentally (I'm a bit biased here, I'm an experimentalist) this is a bunch of crap. No one is anywhere close to doing anything like this. First we need to show experimentally that his idea of creating stressed structures and twisting them apart will work, and no one can touch that right now. How do you create the strained structures? In addition, this would have to be done in vacuum to keep interactions with the environment at a minimum. It would also have to be done at cryogenic temperatures to keep the atoms from vibrating out of place (remember we're relying on two unstable structures). This leads to an expensive and difficult proposal.
There are a few groups (I know of Wilson Ho's group at UCI - great pictures by the way) which are working on joining one atom with another. It's done under extreme conditions inside a scanning tunnelling microscope, and it's VERY hard. They don't do any twisting, they do the sensible thing and use applied voltages to excite and bind atoms.
Quite frankly, Feynman and Drexler have been major impediments to experimental nanotechnology for a long time now. There are plenty of interesting, self-assembled structures out there that can do some amazing things which are not related to the assembler idea. There are plenty of good research groups which are dismissed funding in favor of groups which are flailing around in the dark.
The first thing you learn about nanotechnology is that any intuition about the macroscopic world doesn't carry over. Trying to fit our notions of the rest of the world into the nano-scale world is foolish and wrong. Those strait lines between atoms in a molecule are not always strait.
Before we try to use nanotechnology to shape the future we need to understand it. Drexler gives the impression that we already do, and that it's time now to move foward, but no one knows how yet; we just don't understand.
I think it would be wrong of us to say that molecular assembles are impossible. Personally, I think it is possible, and that's why I do this. But to say that they are "close" or to give ANY prediction of when we will see them is just silly. After saying that, let me say something silly and say that although I hope to see nanotechnology come of age in my life, I don't expect to.
But that's just my point of view - I dislike Drexler's constant reference to Feynman, his total lack of any experimental pedigree, and his unwillingness to take on board the views of those who actually know a bit about what he spouts off about, because they have tried it.
Reading the article, it seems that Drexler in his second letter ignores the fact that he is contradicting what he says in his first letter, because the mechanisms proposed in the second would inevitably require the very same 'Smalley fingers' that he derides in his first polemic.
Drexler is just pissed that someone with credibility and experience has pointed out the holes in his arguments, and cast doubt on his percieved achievements (which are roughly on a par with other Sci-Fi authors, IMHO).
Leave it to guys like Smalley - we'll end up with nanotechnology that works - maybe not the grand self-replicators in the first iteration, but at least we'll have technology rather than the PR puff and self-publicity that characterises Drexler's current output.
Sorry for the rant, but Drexler really, really pisses me off.
oh brave new world, that has such people in it!