Nanotechnology: Are Molecular Assemblers Possible? 513
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."
Raises interesting questions (Score:4, Interesting)
Re:Raises interesting questions (Score:5, Interesting)
By this time it will not be possible to buy a Ferrari, but only to license a copy. Therefore official Ferrari licenses will be a hot commodity for the wealthy and they will slap licenses on the car windows, the cars however will not become their property.
Of course thieves will see this trend and nab the licenses out of the Ferrari, instead of the car itself, which will be worthless.
Hence you could copy a Ferrari, but what good would it do you, as it wouldn't be yours anyway.
Re:Raises interesting questions (Score:3, Interesting)
Re:Raises interesting questions (Score:5, Insightful)
If you're using a molecular assembler to copy the ferrari, you could use it to copy the license certificate, which would be an exact duplicate so unrecognisable from the original.
Even if they register licensees, you just copy your friends passport (after instructing the assembler to change the photograph) so you can 'prove' you are $FRIEND and you're the legitimate licensee.
However, if molecular assemblers ever become mainstream I'd rather design my own car and let it assemble that. If everyone is driving a Ferrari I'd rather have something different.
Re:Raises interesting questions (Score:2, Funny)
Well, had you written "Rolls Royce" instead of "Ferrari", I'd have whinned something like : "if it's perfect, I don't care if it's not unique"...
Re:Raises interesting questions (Score:2)
Instead, why just not rob your friend? And why does he have a Ferrari in the first place? What's with your social circle? Does Ashcroft know?
'this time' is now... (Score:2)
When you can copy a car as easily as a document, the car master (think DVD) will become the target, and that will be the time when copies of vehicles become something to liscense, unless of course, you build your own, like many of us already do today.
Re:Raises interesting questions (Score:3, Interesting)
Most of the major auto makers of course will than start
Keep your fararari. (Score:2)
Wait, was I talking about cars or linux?
Re:Raises interesting questions (Score:5, Insightful)
Buy with what money? When you can replicate all the food, clothing, shelter, weaponry, medicine, entertainment, and all the general goods you will ever need, what, exactly, is the point of money? Without scarcity, money ceases to exist in ALL it's forms... With a replicator, the entire CONCEPT of economics will go the way of the feudal system; just another quaint idea you can read about in your replicated bookery.
Re:Raises interesting questions (Score:3, Insightful)
Don't forget that land property will still have value in a replicator-enabled society. Energy will also probably need to be purchased.
Re:energy from chemicals (Score:3, Interesting)
Neil Stephenson's Diamond Age is probably a more reasonable assesment of where things will go. People will still be employed in the design of new machines, and will be able to afford better pieces of land, and more electricity (Stephenson also suggested that perhaps handmade items would become statu
Re:Raises interesting questions (Score:4, Insightful)
Re:Raises interesting questions (Score:3, Interesting)
We will still have money, but we will buy different things. Information and services will still be scarce and need to be purchased. Also, the inputs for these assemblers will still have some scarcity. Obviously the biggies like carbon and oxygen aren't hard to get a hold of, but rare elements will be very valuable.
Here's some free investment a
Re:Raises interesting questions (Score:2, Insightful)
You can already be arrested for making a copy of your friend's ferrari -- they've got copyright in the design of the car, after all.
Re:Raises interesting questions (Score:4, Insightful)
There is an entire 'kit car' industry, you might want to go have a look at it.
Re:Raises interesting questions (Score:3, Interesting)
Re:Raises interesting questions (Score:3, Interesting)
Wow, we're already shaking the foundations of some markets (low-to-zero-cost products are not historically very common, but digital assets have essentially zero duplication costs), but so far it's been limited to the digital world. Expect major changes if we can at any time expand that into the physical world...
Simon.
Re:Raises interesting questions (Score:4, Funny)
Re:Raises interesting questions (Score:4, Funny)
They try to come after you (Score:4, Interesting)
http://www.mb-portal.net/html/news/special/2003
Some guy from Poland "copied" the new Mercedes SLR, long before the real car hits the market. Mercedes tried to buy it from it to get it off the streets. Because that failed, they sue him.
Marc
Lest we forget (Score:5, Interesting)
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 [zyvex.com].
Re:Lest we forget (Score:3, Informative)
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 d
Drexler did WAY more for nanotech (Score:2, Insightful)
If you read the article.... (Score:3, Informative)
From the above linked article:
Re:Lest we forget (Score:3, Informative)
Re:Lest we forget (Score:5, Interesting)
Kurzweil (Score:5, Informative)
http://www.kurzweilai.net/meme/frame.html?main=
Well... (Score:2, Insightful)
Yum (Score:5, Funny)
How long would it take one of these assemblers to make a cup of "Tea, Earl Grey, Hot"?
Re:Yum (Score:2, Funny)
Re:Yum (Score:2)
How long would it take one of these assemblers to make a cup of "Tea, Earl Grey, Hot"?
This is modded as funny but it raises a significant point. The atomic world is not rigid at all scales. Atoms can diffuse, dislocate, etc. Thermal motion and entropy must be considered. How can a deterministic molecular assempler allow for these?
Re:Yum (Score:5, Funny)
Especially if your replicator is another fine product of Sirius Cybernetics.
Forceful language indeed (Score:2)
You don't get it. You are still in a pretend world where atoms go where you want because your computer program directs them to go there. You assume there is a way a robotic manipulator arm can do that in a vacuum, and somehow we will work out a way to have this whole thing actually be able to make another copy of itself.
Wow. If I talked that way to my corporate overlords I'd be kicked to the curb. Maybe I should have been a scientist!
I can see what the problem might be (Score:2, Interesting)
Imagine that you were given the task of designing a machine to lay bricks. This probably would not be all that difficult, considering all of the things we already do with robots.
However, the problem becomes much more difficult if I add the stipulation that the machine be constructed entirely from bricks and mortar.
Re:I can see what the problem might be (Score:5, Insightful)
Re: (Score:3, Insightful)
Re:I can see what the problem might be (Score:2)
I think that's a flawed analogy, because the machine the C compiler needs to execute it can be built without any need for a pre-existing C compiler, and we can build that machine in a manner that ensures it will be possible for it to execute the C compiler.
We don't have such a luxury when building molecular assemblers. The "machine" we run on isn't under our control: It's the particle interaction laws nature stuck us with, an
Re:I can see what the problem might be (Score:5, Insightful)
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
Re:I can see what the problem might be (Score:3, Interesting)
Re:I can see what the problem might be (Score:2)
That is true, but those assemblers are not general-purpose: They are only capable of constructing certain kinds od molecules, and cannot be used to create completely arbitrary molecules.
The difficulty is that the "tool" is part of the chemical environment: You can't grab an atom without forming bond(s) to that atom, and doing that alters the way that atom interacts with other atoms. The detailed structure of the tool must be compatible with the
Re: (Score:2, Interesting)
Re:I never understood how it was supposed to work. (Score:4, Insightful)
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.
Re:I never understood how it was supposed to work. (Score:4, Informative)
For a good book check out The Computational Beauty of Nature [mit.edu]). 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.
Re:I never understood how it was supposed to work. (Score:2, Interesting)
From the article: (Score:5, Funny)
Aye, this is something that almost all
required reading (Score:4, Informative)
Re:required reading (Score:4, Insightful)
Love and Molecular Assemblers (Score:3, Interesting)
*sigh* I'm touched.
Also I found it interesting that the usage of Nanotechnology was changed so greatly that the creator of the term accepts the newer phrase 'molecular assemblers' for that process.
It's The Snack Food, Stupid! (Score:3, Funny)
They are possible, and Twinkies(TM) provide the proof. They are manufactured with absolutely no nutritional value whatsoever, and this is only possible if vitamins and minerals are screened out at the molecular level.
DNA (Score:3, Interesting)
Not really. (Score:2)
The whole point of nanotech is that it doesn't work like that: you can supposedly add one atom at a time anywhere on a molecule, or pluck an atom out of the middle of something. Which makes the problems much more difficult.
Drexler should get credit for being a populizer of the concept of nanotech, but it's good to see an expert in the field giving him some peer review.
Jon Acheson
Grey goo (Score:2)
I find it sort of reassuring that a technology as potentially fantastic (and therefore treated with immense enthusiasm) has to undergo a long period of maturation before people can even agree on the basics...
Simon
Well, I read the letters (Score:5, Interesting)
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.
Re:Well, I read the letters (Score:2, Informative)
With regard to the hemoglobin molecule example this is precisel
Re:Well, I read the letters (Score:5, Insightful)
I could be a bum on the street and still tell you the correct science. You might not believe me, but it's still correct.
As for Mr. Drexler, I've read Nanosystems. Mr. Drexler doesn't know chemistry. If he did, he could tell me all the cool new reactions we need to create the stuff he proposes. Or the chemistry/physics needed to do a nanoassembler.
I've done plenty of computational chemistry research--it's about 90% of my Ph.D. And you know what? I can happily draw whatever molecule I want on the screen and predict the properties. Can I make it?
NO, not necessarily!
There's a reason a lot of people hate orgo class in college. Chemistry is tough--there are a lot of exceptions and the best synthetic chemists have years upon years of experience in lab bumping their heads against walls trying to make things.
Drexler needs to try some synthetic chemistry. Maybe then he'll rethink his nanoassembler idea.
Re:Well, I read the letters (Score:4, Insightful)
No, chemical reactions don't happen like that. Molecules do not randomly appear in product positions, nor do they follow nice straight lines to form products. They follow complicated, n-dimentional reaction coordinates involving deformations of both product and reactant. Drexler mumbles something about mechanical arms and ignores this point. Using a different name for something that is functionally identical to a "Smalley Arm" does not mean that you can cavalierly ignore all the problems which have been shown to exist for a "Smalley Arm".
Re:Well, I read the letters (Score:5, Insightful)
You can't just say "well, this works with an iron atom in a hemoglobin molecule, so let's make a different carrier molecule with the same geometry, put it on a robot arm and use it to collect up nickel atoms, or whatever". Biology works because over billions of years a limited group of reactions has been found to work on a limited range of materials, in bulk and in carrier liquids. The notion that this means you can just build little tiny cranes and waggle atoms around does not follow.
Let's see how well that argument stands up in paraphrase:
No one is suggesting that we would blindly copy the geometry of some biological mollecule (without regard to it's charge distribution, orbital occupation, potentials for resonences, etc.), attach it to a robot arm, and expect it to do the job, any more than we would build an airplane by glueing birds wings on a school bus.The whole biological-existence-proof line of arguments came up because some people (including Smalley, IIRC) claimed that building macroscopic objects out of components assembled with atomic precission was impossible in principle. Life forms are a clear concrete example of something that is build in exactly that way.
Now, saying that birds exist does not tell you how to build an airplane (though birds might be a good place to look for hints); all it does is shoot a big hole in the argument that flight is impossible.
-- MarkusQ
Re:Well, I read the letters (Score:3, Insightful)
Drexler thinks he can ignore all the other interactions to make an unreactive assembler work in a general case,
He most clearly does not. He thinks (and, as I've stated, I think he's correct) that these are engineering problems and not "basic science" problems. No one is saying they can be "ignored" anymore than they would say that things like drag can be ignored when designing an aircraft. But that doesn't mean (as Smalley seems to conclude) that the whole thing is impossible, anymore than the existen
Re:Well, I read the letters (Score:5, Insightful)
If you'd read the letter a little more closely, you would have seen that Drexler didn't address the problems with those 'sticky fingers' because he'd thought of the problems a long time before smalley, and had thus dismissed that idea a long time ago.
The worrying thing is that Smalley found it necessary to use an already dismissed idea as a straw man to try and make Drexler look bad. Not very scientific. And certainly not conductive to the advancement of science.
From other's (I'm neither a physicist, chemist or biologist) reactions on Smalleys technical arguments, I gather that his understanding of proteins is 20 years outdated, since that's how far back it was proven that proteins can function outside of water.
Biology works because when it found one reaction that worked, it stuck with it and developed it further. If something is not demonstrated in biology, that doesn't mean it can't exist. Conversely, if something is demonstrated in biology (and as Drexler argues, that is true for molecular assemblers), we know it's possible.
The idea of a making and breaking chemical bonds with molecular precision has already been demonstrated. That it won't work with every combination of molecules is a given. But then, it's very difficult to drive a nail into a wall if your hammer is knitted out of wool, and the nail made of rubber.
The bottom line in this debate is that Drexler, and with him many others, believe this is a promissing direction for research. Unfortunately, Smalley is the one holding the purse (he's with the NNI), and doesn't want any research in that direction.
Drexler talks about being prepared, Smalley about not worrying the children. Regardless of who is right on the science side, what do you think is the wiser decision?
Re:Well, I read the letters (Score:3, Informative)
I suppose if I finished reading my copy of Drexler's Nanosystems, I'd see more information a
My summary (Score:4, Funny)
So I can read the debate but damned if I can make an intelligent contribution to it. Maybe I can translate it down a little:
Drexler: Yo, machine-phase chemistry is the bomb. We can put atoms wherever we want and make anything we want!
Smalley: No you can't, dork. Atoms are not little balls and bonds are *really* not little sticks. You can't build molecules like tinkertoys.
Drexler: Enzymes do it in nature, therefore it's possible.
Smalley: Well, if you wanna make more better enzymes, great, but enzymes only work in water-based living cells and it's kinda hard to grow a cell phone from organic components.
Drexler: My machine-phase chemistry will be to living enzymes as a metal airplane is to a bird.
Smalley: Whatever. Go do your "machine-phase chemistry" and come back when you've actually built something. Hint: I think it's gonna take you 200 years.
I think Smalley is wrong when he says that it's by nature impossible. And I think Drexler is wrong when he says nature has already provided an existence proof. I think we should get started on those 200 years of work and see what we can do!
Scaring children - classic quote from Smalley (Score:5, Funny)
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.
Never say never (Score:3, Insightful)
Re:Never say never (Score:2)
Possibilities... (Score:2)
Re:Possibilities... (Score:3, Interesting)
His Third Law is more well known, "Any sufficiently advanced technology is indistinguishable from magic."
However, there's also Asimov's Corollary to Clarke's First Law (1977):
Yesterday's crazy idea... (Score:2)
Applied science is a big mountain, and we're still mucking about in the foothills.
-Carolyn
These discussions are almost irrelevant ... (Score:4, Insightful)
As Dexter quotes Smalley:
Molecular assemblers are not currently possible so we're not discussing 'now'. As for the future, well anything is possible. Look back through history and I don't think anyone can seriously say that anything is impossible given a long enough timespan - given enough research and progress and time, humans will probably find ways to overcome any physical, chemical, biological etc limit.
So if the future is certain, then all these discussions are about is when. Given the lack of developments in the nanotech area, i doubt anyone can give an accurate timeline as more research/developments is required.
Therefore the whole discussion seems like a pissing contest since neither side can really provide any solid info to predict when their predications will become true.
If I had to bet (Score:5, Insightful)
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
Re:If I had to bet (Score:3, Insightful)
>lifetime) that we will never detect planets around other stars,.... etc....
I see this argument all the time and it's totaly falacious. In my lifetime scientists have claimed that artificial inteligences will be so far superior to human inteligences that they will rule the world for us. When would this occur by? Well according to some 1960s AI pioneers, we'd be ruled by AIs by the 1980s.
Meanwhile in 2003 we'r
Re:If I had to bet (Score:3, Informative)
You wrote:
Then
Re:If I had to bet (Score:3, Insightful)
But the problem is this--Drexler's theory is that we can make an arbitrary object. That's not necessarily true from biochemistry. There are a great diversity of molecules made by nature. But synthetic chemistry has been able to make molecules never made by nature.
Does that mean we can use biochemical techniques to assemble macroscopic assemblies? No.
The trick that life uses is called "self assembly." We haven't the least clue how proteins
Re:If I had to bet (Score:4, Insightful)
Strawman. The issue is complex components that have every atom where you want it (with perhaps some acceptance of a very low error rate).
Strawman. The proposal is that we should be able to make arbitrary members of a huge class of useful objects, which isn't the same thing at all.
Strawman and argument from incredulity. First, this isn't Drexler's position, and second I see no reason why we couldn't, since trees do it on a regular basis.
Strawman. Ignoring the fact that we do know a great deal about how proteins fold, it doesn't matter since we don't need to understand the details anymore than the Wright brothers needed to understand how bird poop in order to build an airplane.
Argument from incredulity / ignorance (we don't know how to do it, therefore it can't be done) and Strawman.
-- MarkusQ
Re:If I had to bet (Score:3, Insightful)
Cells can't make exact copies of themselves and I don't believe a group of cells working together would have any more luck in completing that task.
Exact? No. But functional? Sure. Cells do it all the time. In fact, birds do it. Bees do it. And from what I've been told, even educated fleas do it.
He's arguing that, without breakthroughs in chemistry beyond what we can currently imagine (ie some manner of "enzymes" not dependent on water or some other liquid), any molecular assembler that depends o
Re:If I had to bet (Score:3, Informative)
It's a blurry line, but if I understand you correctly, you're saying you could (in the cell example) use nanotechnology to make the proteins themselves, but don't care where they float around in the cell itself, so long as they're in the general area. Like the mitochondria, the cell wall, etc etc.
Pretty much. The only exception is that if we needed to we could position the parts more exactly. Cells do this, by the way. They allow stuff to float at random only to the extent that exact positioning doesn
Re:If I had to bet (Score:3, Informative)
Re:If I had to bet (Score:3, Insightful)
Drexler is making handwaving claims that this will be doable, without actualy coming up with a concrete explanation of how it could be done.
Hardly handwaving. [barnesandnoble.com]
If you have specific objections, raise them. But don't call something handwaving just because you haven't read it.
-- MarkusQ
I'd take that bet (Score:3, Informative)
If you strip away the fancy words (and shamelessly simplify), this becomes much more obvious:
Yes they are possible (Score:5, Insightful)
Cells do it (Score:3, Interesting)
I'd love to read this article... (Score:2)
Atom Level Manipulation (Score:3, Informative)
Here [smalltimes.com]
From the article:
"an atomic manipulation facility, unique in the world. This atomic manipulation facility will enable a new generation of experiments to unfold. It will allow McGill researchers to construct new devices atom by atom, thus developing the science and technology required for future electronic and biochemical systems."
To Dr. Smalley (Score:2)
-- Wernher Magnus Maximilian von Braun (1912-77)
A Small Observations (Score:2)
Then, you can't use positional assembly, because objects don't stick to eachother just because they get close to one another.
So, uh, which is it? Do or do not compatible molecules bind or adhere when brought in close proximity?
I'm not a chemical engineer (obviously), but even I picked up on this interesting contradiction.
--Dan
The Human Body, Man (Score:2)
Given this, it seems obvious that nanoconstruction at some level is possible. That doesn't necessarily mean we can throw a bunch of elements together and direct them t
Existence proof. (Score:3, Interesting)
A ribosome (a combination of several large protein molecules) constructs arbitrary protein molecules from individual amino acids according to the instructions on a strand of RNA (copied from DNA). Sounds like a molecular assembler to me.
Now, as to whether they can be made smaller and more flexible than that (nanotech's "universal assembler") is another question -- ribosomes may turn out to be the minimum possible assembler. Or not.
It really is quite simple... (Score:3, Insightful)
The smallest self-assembler is equivalent in size to the smallest microorganism. Nanotech devices cannot do better than the already extant nanotech devices: all the enzymes and proteins in a cell (any cell, any virus, any bacterium). Not a single enzyme or protein in any cell anywhere is capable of reproducing itself from first principles (atoms). Even the small "self-replicating" prion protein cannot make itself from scratch. It requires a premade template protein assembled by ribosomes using instructions provided by RNA which was produced by RNA polymerase, which is itself a copy of a DNA "library" generated by an evolutionary decendent of RNA polymerase called DNA polymerase.
The closest thing to a self-assembling "machine" would be the hypothetical self-replicating RNA molecule of primordial, pre-life earth. The presumed precursor to all things living today. But you don't get much use from a self-replicating RNA except more copies of that RNA, which doesn't even do anything but copy itself. It cannot be a universal replicator. Nothing can. Information takes space. All the information needed to replicate the smallest possible item, a prion, is exactly the size of a prion - and it doesn't do anything de novo, just refolds an already extant protein generated by the minimum-sized machinery necessary to generate that protein. Thus a virus could be considered a measure of the smallest possible self replicant capable of producing complex systems (the virus).
But wait! A virus CANNOT be the smallest possible self-replicator. It REQUIRES a pre-existent cell with all the machinery necessary to start from first principles (atoms and small molecules) and generate more complex "machines" and structures. Thus a virus is not, and can not be considered self-contained anymore than a prion can. No, a full-blown cell, the smallest being independently replicable bacteria, are the smallest possible self-replicator starting from first principles (atoms and molecules as a source of building material). Drexler, not being really versed in anything beyond simple chemistry and physics sees things through rose-colored glasses, and ignores the facts around him.
If a self-replicating, autonomous nano universal replicator were actually possible, it would have won evolutionarily as the most efficient replicator and it would be the dominant form of replicator on earth. Hmmm...nope, none around here. There isn't even anything CLOSE to such a beastie within ANY living organism of ANY type.
Energy source (Score:3, Insightful)
I side with Drexler. (Score:3, Interesting)
I think Smalley's argument is that for a specific reaction between two molecules, you need something like an enzyme designed specifically for that reaction. The number of possible molecules is astronomical, and the number of pairs astronomical squared.
I hear you can treat most of molecules mechanically except for a few dozen atoms surrounding the reaction site. That limits it to, let's say, 2^^30 possible molecules, so 2^^60 reactions you need specific enzymes for. Designing any one of those 2^^60 enzymes or reaction paths is feasible. Making an index iwth 2^^60 entries is feasible, given atom-scale memory, although it isn't microscopic. Drexler suggested such an index for diamondoid struts of different sizes in "Nanotechnology:
The real number of enzymes needed is much smaller than 2^^60. To get a self-assembling molecule, assuming you feed it the right basic building blocks, you don't need a universal assembler. DNA limits itself to 4 molecules with a single type of connecting part. Proteins limit themselves to 24 molecules (I don't know if the connecting parts are standardized but I suspect they are). Ribosomes can construct ribosomes, so we already know self-assembling machines are possible.
An interesting question is, given an assembler that knows how to do some fixed set of assemblies, what can be built? How big a set is needed? The smaller the set, the less work is needed to get the correct configuration for each reaction. Perhaps we need specialized factories for some building blocks with standard connectors, then just a tape-reading assembler that can connect standard connectors? Standards simplify things.
from an actual nanoscientest (Score:5, Insightful)
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.
Nanotechnology timeline (Score:4, Informative)
My Nano Assembler design (Score:3, Interesting)
Anyways here's the design. It is simple and achievable. It is not conducive to building/replicating itself easily though.
The core is an STM microscope-like device, with many parralel tips each working on its own square millimeter (or smaller) area. Needle Tips or fingers doped with the next mollecule (properly oriented) to be inserted move along a conveyor belt where each are inserted into one of the parallel heads, the head then sticks the molecule in place, then the needle is sucked out, and sent to be refilled.
I don't really have a process for making mollecules, and placing them in the proper orientation on a needle.
The one good thing about this design, is that there probably exists a needle material than can react "properly" with any given mollecule, such that it can 1) capture it, and 2) release it. (One method of releasing could just be to jab the needle quickly forward, flinging the package into place).
There's one problem with Drexler's universal assembler theory, with little publicity, that is only partially solved by my design. There is not an infinite number of universal assemblers created instantly, and as a secondary problem, programming them to work and move around cooperatively is not easy, and increases their required size if only because of the massive cpu they need to operate with.
The Other issue only partially addressed is speed. If everything is built using 3d tetris-like merging of 10nm building blocks (mollecules), then finishing a square milimeter takes 10B blocks. A quadrillion blocks makes a cubic milimeter of something. Even at 1 billion blocks per second, it takes 11.5 days to make 1 milimeter thick object. The billion blocks per second seems outrageously high to reach, but another way to increase throughput (but increase congestion of feeder needles) is to have denser parallel heads. If each head works on a square micrometer area, then building a cubic micrometer object takes 1 million 10nm blocks. At (only) 100K blocks per second, a 1mm thick object takes 10,000 secs = 2.77 hours
There's one other big problem. Like building a house of cards on an uneven surface, mollecules won't necessarily maintain a desired orientation without simultaneously placing adjoining molecules to couterbalance them. Seems like there would be a solution to this, with all the arms in such close proximity, but it would also slow down the process.
Who to believe? (Score:5, Insightful)
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.
For now, Smalley is right. (Score:3, Informative)
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.
It will happen. (Score:3)
Anything can happen with science. Magic is just what science cannot explain, because we have not figured out how to do it yet. But eventually, given enough time and resources, anything is possible.
Common misconceptions about our nanotech future (Score:3, Interesting)
2BorgDrone [slashdot.org]
However, if molecular assemblers ever become mainstream I'd rather design my own car and let it assemble that. If everyone is driving a Ferrari I'd rather have something different.
When molecular assemblers become mainstream, having a car would be rather pointless. First, there are unlikely to be any streets where you can impress chicks, since everyone would be able to live wherever on Earth they like. Second, there probably won?t be any roads, since you don?t need to transport goods (they can be manufactured from CO2 on the spot) and it?s easier to fly people from A to B. Third, designed cars would be as old-fashioned as horse carriages now ? smart completely transformable people-movers would be all the rage. And forth, you will be able to drive any kind of car in your personal virtual reality simulation, so you don?t need to actually design the car (just program how it should behave) and the issue of IP would be moot.
2jchoyt [slashdot.org]
Money will still have value. Someone has to create and/or design food, clothing, medicine, entertainment, etc.
Strong AIs will be able to create and or/design everything, including these things you describe. Furthermore, people will not need food, because it will be easier to just get energy from the environment without any conscious actions like eating from your side. Clothing is likely to be designed for the sake of it. Most couturiers are not in this business for money, they do it because they like it, and when all fabrics and basic production operations will become free, as well as everything they need personally, they are unlikely to charge you anything for their latest fashionable clothes. Medicine will not be used, because our bodies will be redesigned to include a smart AI-based immune system, capable of fixing most problems, except, may be, for being in the epicenter of the thermonuclear explosion. So most things you mention will not be needed and those that still will be needed, will be done by professional volunteers for free.
Re:Whats in a name? (Score:2)
What I want is one of those robotic horses (a chevaline) and a Kevlar duster-type coat. That would make me a Cosmic Cowboy of the Future. Wait, would that make me Cowboy Neal?
Let's not even start talking about the Mouse Army among these rogues on Slashdot... Thousands of teenage Asian girls, oh boy.
Crichton, not Stephenson (Score:2)
Michael Crichton a credulous luddite? No way, you say. Read the foreword to Prey and the book Travels. The guy's a whack-job.
Prey was better the first times I read it: Sphere and The Andromeda Strain.
Re:Tinkering with nature (Score:5, Insightful)
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