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The Evolution of Nanomachinery
csy writes: "Harvard's George Whitesides has a wonderful article on Nanomachinery in this month's issue of Scientific American. He casts doubts on the Drexlerian vision of mechanical assemblers, and argues that biology and chemistry, rather than mechanical engineering point to the answers in the quest for nanomachines."
"Whiplike tails, that make these E-Coli look like furry tampons."
The article talks about the machinery of cells as an example of existing nano-machinery on which we should base the development of artificial nano-machines - but the proteins and other bio-molecules in a cell are actually pretty large compared to some of the things we can do even now with STM microscope tips and carbon nanotubes. Even the smallest virus is 0.05 microns across, and we're already regularly making semiconductor components on that scale. Admittedly the virus has some complex internal structure. But biology uses a very limited set of chemical elements (mainly C, H, O, N) and I think one of the main ideas with nano-machines was that there's no need to restrict yourself to the limited set of things used in biology...
Energy: time to change the picture.
The possibilities, if we just can figure them out, are enormous. You can create any kind of human cell out of those, the genetic code is all in there.
Bio-informatics is probably just in the very beginning of something huge. Once we gain full understanding of the human body we have the code to life itself. It sure is a thrilling thought
Probable impossibilities are to be preferred to improbable possibilities.
Aristotele
Comment removed based on user account deletion
If ever there is any nano inspiration, then there would be the combination of Neumann Machines with Nanotechnology.
Muchas Gracias, Señor Edward Snowden !
Let's build us a microscopic wheel and put an Amoeba on it.
If they are to pick up atoms with any dexterity, they should be smaller than the atoms. But the jaws must be built of atoms and are thus larger than the atom they must pick and place.
Atoms, especially carbon atoms, bond strongly to their neighbors.
I really don't care if the "jaws" are Drexlerian or biochemical. As long as the damn thing works, we're golden. An assembler that is a mix of mechanical and chemical, or any other approach is still a successful assembler. As for his concern of how to make a machine self-replicating, we don't need the assembler machine to be tiny, just to make tiny stuff. Room for template storage is easy.
1Alpha7
Live to be Moderated
There's room for lots of approaches, I'm sure.
I felt the author was a bit disingenuous with this quote:
"A little submarine that was to be a hunter-killer for cancer cells would have to carry on board a little diagnostic laboratory, and because that laboratory would require sampling devices and reagents and reaction chambers and analytical devices, it would cease to be little."
This is clearly a mix of humor and a rhetorical stab at the nanotech research community. That's fine for a popular magazine like SciAm, but it's not a serious analytical point. We'd be kidding ourselves to pretend that the only possible techniques for identifying cancer cells when parked before them on the nanoscale would require lab reagents and little miniature lab assistants in white coats drawn by Gary Larson.
Of course SciAm has always been a popular publication masquerading as a scholarly journal and evocative claims have long been the stock in trade.
Good one, I guess.
There are some interesting ideas here, but I wish they had been presented as such, rather than as evidence that nanomachines won't work. Nanomachines can't self-replicate by placing individual atoms with tiny pincers, therefore self-replication is impossible. Nanosubmarines 100nm in size would be too small to steer, therefore nanosubs are impossible. Jeepers, use a little imagination.
I think his claim that the molecular assembler is "less the solution of a problem than the hope for a miracle" will seem quaint in time to come.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
Second, think about it. The ideas in this article bring some debates. We as humans are always trying to make computers life-like, trying to induce a sense of self with in. We want the computer to make a choice with out the guidance of a complicated algorithm. If we do use the approach suggested in this article than these nano-machine will eventually develop a conscious!
Do we wanna play this game?This SIG pulled due to lack of funding. (This damn war is costing too much!)
I'm so concerned whether they are made of organics or metal (I used to teach chemistry and physics), but I have some work for them to do right away.
Memo to future small robot type guys:
1) Clear out any hardening of the arteries that I have already developed (I'm 50 years old)
2) I hate flossing--could you do that stuff by launching from my mouthwash?
3) About that pain in my lower back? Could you head down there an do a diagnosis? I would hate to let a bone cancer get a headstart. Oh, if there is a tumor or something bad, please take care of that while you're there.
4) Say, Viagra work but it is very expensive. Could a bunch of you tools help my tool--every once and a while? But please give me warning!
5) Hey, I know that this is not so important, but the Q-Tip package says don't use them in the ear canal. Like many others I have been feeling guilty about this for years. Could you guys...you know...that waxy stuff?
6) OK up here in the macro world we have these utilities called McAffee and Norton that look for problems and then if I give the OK, they fix what they can. Well, can we work out something like this, only on your level.
7) Gee. I almost forgot being a diabetic. You guys need to fix that first.
8) And taking that anti-depression medicine Zoloft..could you do something in my brain. BUT PLEASE BE CAREFUL THERE GUYS!
Thanks,
Brent,
Your Commander-in-Chief
Help end the use of Sigs. Tomorrow
A few months back Machine Design magazine did a good article on the coming of Nano technology. It's on their website at http://www.machinedesign2.com/turnstyle.php?ID=100 0... and pretty much gives a good 50,000 foot view. Only draw back is that it's in PDF again.
when they ban enctryption only criminals wi$21*J *#JF$%!@#$':
This article is just plain wrong. The Drexlerian vision is based on Wet Nanotechnology (meaning biology and chemistry). Eric Drexler is very much against the notion of Dry Nanotechnology - in fact, most of his blueprints for 'nanoparts' are based on proteins.
What is it with all these morons at the universities trying so hard to discredit Drexler? Are they jealous that they didn't think of it first? It sounds like it.
For example, Drexler focused on mechanical computers, with little rods moving back and forth. Does he think nanoscale quantum computers, driven by electricity, can never work? No, but for his book he wanted to focus on things he could be sure would work. Because nature includes little machines, he was sure you could use little machines to build things like tiny computers.
His first book, Engines of Creation, is pretty much about existance proofs. He figures you can probably make an assembler with just 150 million atoms, so then he assumes it will take a billion atoms (just to be on the safe side) for the rest of the discussion.
And in his discussion of how we will get these magic assemblers, he said that one possible route was biological: use tailored cells to make new cells that are closer to what we want, and iterate. He isn't ignoring biology, or reality.
The article is weak. Read Drexler's book instead; it's online so you can read it now for free.
Engines of Creation
steveha
lf(1): it's like ls(1) but sorts filenames by extension, tersely
This is the kind of comment that could only be made by a narrow-minded engineer who lacks any appreciation of the state of modern biology. The naivete expressed here is rather appalling.
I see absolutely no hope, not even a serious promise, that nanotechnology will accomplish anything at all against disease at any time in the foreseeable future, let alone in 10 years. Can anyone show me so much as a sketch of a nanotech machine that could feasibly operate against HIV, or rhabdovirus, or salmonella, or botulism toxin? The very idea is ludicrous, and is offered only by people who are unaware of what's going on in molecular biology.
In biology, we already know what is possible. For example, there exists a naturally evolved biological machine that is a mere dot only a few hundred microns across that can, given an energy source and the proper environment, assemble a completely functional human being. If that sounds too ambitious for you, a related small blob exists that requires only a little sugar, water, and yeast to assemble a flying machine with a sophisticated onboard computer -- it's called Drosophila. It posesses a sophistication that trivializes the grandest dreams of the nanotechnologist wanna-bes. Heck, even (especially?) E. coli looks like a colossal dreadnought of overwhelming complexity when stacked against the rubber-band powered toys promised (not even delivered!) by nanotech!
Nanomachines as scaled down miniatures of human scale machines is clearly very unlikely to materialize, for exactly the same scaling reasons that prevent us from having human size single cell organisms. Fundamental relationships between mass, surface area and linear dimensions are inescapable. These relationships govern the nature of physical structures of all sizes. Clearly at nanoscale the balance has shifted from a dominance of bulk properties to surface properties that are primarily chemical in nature. Anyone trying to translate an instrumentaility to nanoscale from human scale will fail miserably if they fail to account for the basic physics of scale.
Innovative nanomachines that make use of atomic scale forces are another thing altogether. As Whitesides correctly points out, this is the realm of chemistry and biology, not the mechanics of bulk materials.
This is the kind of comment that could only be made by a narrow-minded engineer who lacks any appreciation of the state of modern biology. The naivete expressed here is rather appalling.
It seems to me that the biologists have been the narrow minded ones. After all, wasn't it Wohler's urea synthesis that disproved the biologist's claims that organic compounds could only be produced by living organisms? Why isn't the synthetic production of self-assembled structures (wet nanotech) a modern analog to Wohler's synthesis?
While all these rods and gears and things may sound like a silly application of macro-scale approaches to micro-scale systems, it actually is all based on atomic-scale forces.
We know from experiments with various tiny-finger-type microscopes that you really can push around atoms as if they were little beach balls, and that bucky tubes really do act like fairly stiff, yet flexible, rods. They really can act mechanically on each other in reliable, predictable ways.
Nanosystems uses these interactions to argue for the possibility of nanotechnology because they are simple and easy to understand. Every argument is reinforced with large fudge-factors and cautious assumptions (for example, it is assumed that any machine will become non-functional or malfunction if a single atom is out of place).
Nobody is qualified to criticise Drexler's work until they've actually read it, and Nanosystems is the real meat of his work. It's also a great book if you'd like to learn more about any of chemistry, mechanical engineering, physics, or computer science, because of the way it ties them all together. The math is heavy going, but in its own way it is every bit as worthwhile to dig through as Knuth's TAoCP.
---
You'd be surprised at the broadband connection available to things crawling around in your hair.
I've been waiting for someone else to say there is never going to be a "gray goo" problem. What a refreshing change from the "nanotech is coming, we need to regulate it before it eats everything" nonsense.
Brackets contain world's first nanosig, highly magnified:[.]
1) Assuming that everything is like silicon (e.g., the MEMS/stiction arguments). This is like arguing that skyscrapers are impossible based on the properties of beeswax.
2) Assuming that everything is like wet chemistry (e.g. all the comparisons to biology). He even tries to draw a dichotomy between these two.
3) General bad logic. The self-replication argument, for example, flows as follows: We don't know how to make anything that self-replicates at present; cells replicate; they do it by assembling things in a linear sequence, rather than 3d; therefore this is a serious problem for nanotech. Not only are all of these steps factually suspect (enzyme structure, for example, is very much a 3D proposition), they don't logically lead to the "conclusion".
4) Strawman arguments; saying things like "Machining and welding do not have counterparts at nanometer sizes" when no one claimed they did, or "There are no electric sockets at the nanoscale" when no one claimed there were.
This isn't exacty an objective or even rational rebuttal to Nanosystems or any of Drexler's other work; instead it seems to be an attempt at persuasion based on the author's knowledge of his own field and ignoring what Drexler actualy wrote.
-- MarkusQ
Ah, are you sure? I've never heard him say as much, and he seems to get along fine with people who are actively working on dry nanotech. How did you come to the claim that he is "very much against the notion"?
-- MarkusQ
Planes are constructed very differently from birds, bats or insects. Evolution can often be a very messy designer, engineers are much cleaner. We can look to nature for ideas, but not neccessarily solutions.
Calm down now. There is not one single discipline that will solve all our world's problems (whether that's in medicine, energy, environment or whatnot). Any further advancements can only be made by inter disciplinary research. Biology and medicine have made great advances with the aid of other disciplines as well: chemistry, physics (e.g. microscopy), and yes engineering (e.g. combinatorial chemistry).
No, engineers by themselves will not find a way to eradicate HIV. But when you're talking about the state of modern biology, we're not exactly sure how to solve the problem. We know on what wall the dartboard is, but blindfolded it is difficult to hit. Nanomachines may not be the best approach, and medicine will probably find a solution before these machines are operational. That doesn't mean it is wasted research money, since there are plenty of alternative applications.
You're correct that we are still FAR away from any useful nanomachines-- if it ever proves feasible. We know how to drag along a few atoms over a surface under very controlled conditions, but we don't know how to make assemble functional 3-dimensional structures. Self-assembly is nice, but it will undoubtedly involve the construction of some very complex building blocks.
Perhaps he should stop talking about it and do it.
Biologically occurring chemical designs are REALLY very good at what they do. So efficient, that we might be tempted to flat out state that even clever mechanically engineered designs will never approach them. But we should keep in mind that in the "design space" that biological evolution works in not every possible idea is tried or tested. Its just that there is the potential for any combination to be explored.
Human (or machine) created designs can come up with "new" ways to do things. Some of those designs might be more efficient in certain applications than biological designs. A simple example might be the wheel. The last time I checked no macroscopic organisms on this planet where using wheels to get around. On flat surfaces (deserts/ice/savannas/etc.) wheels are more efficient than legs. It is not that evolution couldn't "invent" wheels, it either hasn't successfully happened before, or the design was discarded in favor of the more functionally flexible limbs we do posses. Check out the GOLEM project for more ideas.
I do not think that biological designs have the end all say on nanotechnological possibilities. But the science of biology currently has far more small scale tools and vastly greater experience (nature's experience, that is) at its disposal for the development of useful nanotechnology.
When Thales was asked what was difficult, he said, "To know one's self." And what was easy, "To advise another."
Second, it's too bad that the article's centerpiece example, the bacterial flagellum, is not described correctly. Whitesides writes: This is just completely wrong. The flagellar motor is powered by electrochemical (ionic) gradients across the cell membrane, and NOT by ATP. This is not news; it has been known since 1977! (PNAS 74:3060; Nature 272:282; Nature 325:637; Cell 60:439.) Ironically, most of the experiments showing this were done at Harvard, where Whitesides is a professor. Of course, as cool as the rotary motor is, I prefer the bacterial retractile pilus, which is a linear actuator that operates like a grappling hook to pull cells along surfaces. For the twerp who was bragging that nonbiological nanotech can work at scales of tens of nm: the pilus is 6 nm in diameter and probably moves in 0.8 nm steps.
I think I'm going to open a shop and sell nanobots to new-age medicine types.
Me: Thanks for the $200, now this pill and the nanobots will do their thing.
Customer: I can see through this gell-cap, there's nothing in them.
Me: Ah, that's the beauty.
Kind thoughts do not change the world
Uh, someone already thought of that scam. He called it "homeopathy".
Not much really.
I have long maintained that the first product that was mass produced was not an automobile as in Henry Ford, rather it was alcohol as in beer and wine.
That's nano/biotech at it's best.
More recently we have discovered fungi that make antibacterial materials. Now we can actually do open body surgery and have some real expectation to recover from the wounds.
Even more recently we have engineered bacteria to make insulin. We have big tubs of these nano-bio-machines. Each one is a tiny self replicating insulin synthesis plant.
What's the big huff about nano/bio/whatever tech? It's been around for millenia! Only the words used when talking about it are different.
Good judgement comes from experience, and experience comes from bad judgement.
- W. Wriston, former Citibank CEO
In fact, physicists have developed a number of techniques that let us manipulate atoms in ways that nature does not use for building complex structures. For example, STMs and lasers allow us to move single atoms. And we have found out that individual atoms and assemblies are much more stable than previously thought.
You may find an expanded copy of my letter to the editors here.
Whitesides is a chemist and while he has made huge contributions to that field, particularly with his nano-imprint lithography, for which he won a Foresight Prize several years ago, he is not, unfortunately, someone who understands molecular nanotechnology. For that you have to read Drexler's take from the same issue which is here.
Readers of scientific literature must do "reputation" analysis. Would you trust a life-time COBOL programmer to comment on whether or not your JAVA code was well written or crap? I think not. One should judge the Whitesides article from the same perspective.
They're called muscle fibers.
I lerned this when m ywife took anatomy. our muscels are actually based on a molecular motor/ratchet mechanism.
Way cool.
I really don't see the vicious attack that others see. Whitesides is a really intelligent man who employs biologists, chemists, and physicists in his lab and he has been thinking about manipulating very small things for a number of years. I think that his comments on energy sources, assembly, and information storage at the nano-scale are thoughtful and if he appears overly critical, perhaps it is the correct response to the sometimes overly optimistic predictions of others.
[insert clever quote here]
If we are going to discuss nanotechnology we need to be precise. :-)
Current efforts in nanotechnology are not directed towards making "analogs" of things "found in nature with elements not commonly used in nature". Current efforts are directed towards using the laws of physics and chemistry to explore regions of the phase space for atomic structures that are by and large unexplored by nature. Zyvex wants to assemble diamondoid materials -- that isn't a different element, its a different way of putting carbon atoms together than that commonly used by nature. Nature primarily assembles polymers (DNA, RNA & Proteins) which involve creating 2 covalent bonds -- molecular nanotechnology seeks to create more rigid, stronger materials by controlling the creation of 3-4 covalent bonds.
The development of nanotechnology is likely because of the "existance proofs" provided by nature. The development of "picotechnology" is highly speculative, as documented by Hans Moravec in Harvard Doesn't Publish Science Fiction.
It would be nice if people really knew something about a topic before they commented on it.
There are two problems the chemists have. First, they haven't read the material. Second, Drexler is proposing to precisely assemble millions to billions of atoms and the chemists think that is infeasible. That is why programmers can accept nanotechnology to a greater degree than chemists -- manipulating a million or a billion "bits" is something they regularly have to deal with. For chemists the idea is nightmare.
I'd urge readers to educate themselves with regard to the material before they comment on it. If we have to spend all of our time attempting to erase malformed memes we will never get a chance to work on developing new ones.
People need to stop viewing biotechnology as separate from nanotechnology. Biotechnology is nanotechnology, its simply not "molecular nanotechnology" as envisioned by Drexler. The reason for that is that the assembly methods do not exist in nature to assemble very complex molecules (with molecular weights greater than ~3000 daltons) where the precise location and bonding of each atom is controlled. What Drexler is proposing is the assembly of molecules of much greater size with much greater precision than chemists or molecular biologists can manage to perform at this time. They object to the vision because it will be hard, not because it is impossible.
The cold fusion debate is different from the nanotechnology debate. Nobody has made a reasonable case (in over 20-40 years) for why it violates any laws of physics. Whitesides gets the whole nanobot-brownian motion discussion wrong because he picks the wrong size for nanobots. They aren't 100 nm in size they are much closer to 1 micron in size. He also clearly hasn't read Nanomedicine, which discusses a number of means for nanobots to navigate. For his argument to hold water he would have to negate all of the navigational strategies discussed there. He is simply uninformed.
Of coruse, only physics is *real* - everything else is just stamp collecting. :-))
There are ways to provide external power as well, you can lie on an ultrasonic couch and the Nanobots can harvest the ultrasonic energy it supplies. Nanomedicine was published in Oct. 1999, so Whitesides would have had plenty of time to investigate this if he had really wanted to give the topic fair treatment.
No need; it's in Chapter 4. Just follow that link, and search for the word "billion", and read the paragraph under your cursor.
My guess is that 150 million atoms is more like the requirements for an assembler system or perhaps even a self-replicating system.
150 million is for a general-purpose assembler capable of self-replication. And then he rounds up to a billion just to add margin for error.
steveha
lf(1): it's like ls(1) but sorts filenames by extension, tersely