James.Price.Salsman@cat.cmu.edu (06/24/89)
Why I think Nanotechnology is Bogus. By James P. Salsman. First, I think nanotechnology is bogus, because I think that information requires finite space. I believe that there is a fundamental volume that a "bit" must occupy in order for it to be stable as a memory cell. I think that dreams of embedding a typical "AI" program in an object the size of a mitochondria is silly. Second, I think nanotechnology is bogus, because I think that energy requires finite space. I believe that there is a fundimental volume that an "electron volt" must occupy in order for it to be stable and not dissipate. I think that dreams of embedding enough energy for self-duplication in something th size of a mitochondria is possible, because, after all, that's what mitochondria have spent the last billion years of evolution learning how to do. However, I do not think that humans will ever be able to construct anything smaller than a mitochondria that is still capable of self-duplication and still have energy left over to do other things -- like, run an "AI" program. Finally, I think nanotechnology is silly because all of the very-very-very-small logic gate technology I've read about seems too Newtonian-mechanincal and not very well grounded in quantumelectrodynamics that form the laws of nanophysics. Sorry if this is harsh, but I'm trying for constructive criticism. :James P. Salsman (jps@CAT.CMU.EDU) [Well, James, we know that the nuclei of atoms contain information, because a helium atom remains a helium atom and does not "forget" how much mass and charge it has. Indeed we can ionize it, stripping its electrons, and then replace them and it's still a helium atom. The nuclei are orders of magnitude smaller than the atoms we're talking about. There are limits to information storage, but they are in terms of energy (as compared to a background temperature) and they are well understood by ordinary engineers, much less the people who are designing nanomachines. You must realize that on the atomic scale, higher energy means *smaller*. The nucleus is much more energetic than the electrons. X-rays have a smaller wave length than light. This comes straight from E=hv (excuse the ascii!). So there is certainly no physical principle blocking us in this direction, simply engineering challenges. The mechanical logic designs you have seen are mechanical so that we know that they will work; they are "counterexamples against the argument of impossibility." That they do not *use* quantum principles in their operation does not mean that they do not account for them in their design. Indeed, it is quite likely that real nanocomputers will not be mechanical, for the same reason that real computers are not mechanical. But mechanical computers have been built and do work. --JoSH]
turpin@cs.utexas.edu (Russell Turpin) (06/27/89)
In article <Jun.24.01.04.41.1989.23818@athos.rutgers.edu>, James.Price.Salsman@cat.cmu.edu writes: > First, I think nanotechnology is bogus, because I think that > information requires finite space. I believe that there is > a fundamental volume that a "bit" must occupy in order for > it to be stable as a memory cell. I think that dreams of > embedding a typical "AI" program in an object the size of a > mitochondria is silly. Admittedly, the average cell's nucleus is a couple of order of magnitudes larger than a mitochondrion, but it contains a very complex program that directs the creation of a new person. For that matter, the mitochondrion contains its own complex program that directs much of the metabolic pathway. Your "impossibility results" are belied by known counterexamples. Since such programs exist, perhaps you wish to argue that we cannot create such programs, rather than that they are impossible. Russell
landman@sun.com (Howard A. Landman) (06/27/89)
Note: I pulled some of the number below out of my wooly head rather than looking them up, so please feel free to correct them. I don't think any are far enough off to damage the conlusion. In article <Jun.24.01.04.41.1989.23818@athos.rutgers.edu> James.Price.Salsman@cat.cmu.edu writes: >First, I think nanotechnology is bogus, because I think that >information requires finite space. I believe that there is >a fundamental volume that a "bit" must occupy in order for >it to be stable as a memory cell. I think that dreams of >embedding a typical "AI" program in an object the size of a >mitochondria is silly. Well, it's clear that there's a fundamental unit of entropy that corresponds to one bit of information, or more precisely to the loss of one bit of information (information is negative entropy). This gives a lower bound to the amount of entropy that must be generated by any mechanism performing a given computation. However, we are a *LONG* way from running into that limit. We'll probably hit the kT limit first, even with cryonic circuits (liquid nitrogen is still awfully hot). However, in terms of size, it's quite clear that a single atom is enough to store at least one bit of information, perhaps several. There's a tradeoff between density of storage and ease of access, but since you make no claims about ease of access, let me define the storage medium as a modified fatty acid CH3-(CH2)n-COOH. The acid group serves as a handle to identify the start end; after that each carbon bears either hydrogen or deuterium (4 combinations due to stereoisomerism). This give approximately 2 bits of storage for every three atoms (minus a little overhead). Of course if we allow elements like fluorine and chlorine to be used the number of bits goes up and may exceed one bit per atom. In fact, it may not be necessary to stick to linear chains, so that complex data structures may be encoded directly into chemical bonds (gives "tree traversal" a whole new meaning, doesn't it?). As for typical AI programs: you're probably thinking of languages like Lisp or Smalltalk, where the program to print "Hello World!" is about 3 MB in size. It is quite possible to do AI in, say, Forth, where the sizes are orders of magnitude smaller. So, assuming a reasonable program might fit in 30 KB = 240 Kb = ~360 K atoms = 120 K * (atomic weight 12 + 1 + 2) = 1.8 M atomic weights. Now Avogadro's number gives us 1 gram per 6 E 23 atomic weights, so that the matter storing the program might weigh about 3 E -18 grams. That's three billionths of a billionth of a gram. Aw heck, let's be generous and allow 30 MB for the program, that still comes out to 3 E -15 grams. Now I seriously doubt whether that density of storage will be practical because of the difficulty of reading it. It's much easier to read something the size of, say, DNA. But DNA is less than two orders of magnitude larger than the molecule I postulated. Let's call it 1 E -13 grams total. I seem to recall that the human body has about a trillion (1 E 12) cells, and weighs about 250 Kg. So a typical cell weighs something like 2.5 E -7 grams; and our fat, wasteful 30 MB program storage is about a million times smaller. Maybe about the size of a mitochondrion... >Second, I think nanotechnology is bogus, because I think >that energy requires finite space. I believe that there is >a fundimental volume that an "electron volt" must occupy in >order for it to be stable and not dissipate. Darn, JoSH took care of that one already ... just let me add that there's an interesting science fiction study of life built out of nucleons and living on the surface of a neutron star. "Dragon's Egg" and "Starquake" by Robert L. Forward; lot's of good physics, including how to get close to a neutron star without letting the tidal forces get to be a drag. :-) Also ponders the question: How do you relate to a species that thinks and evolves a million times faster than you? Something worth thinking about if we plan on building our own. Howard A. Landman landman@sun.com
alan@oz.nm.paradyne.com (Alan Lovejoy) (06/29/89)
In article <Jun.24.01.04.41.1989.23818@athos.rutgers.edu> James.Price.Salsman@cat.cmu.edu writes: >Why I think Nanotechnology is Bogus. By James P. Salsman. >First, I think nanotechnology is bogus, because I think that >information requires finite space. I believe that there is >a fundamental volume that a "bit" must occupy in order for >it to be stable as a memory cell. I think that dreams of >embedding a typical "AI" program in an object the size of a >mitochondria is silly. That depends on what you mean by "a typical AI program." If you mean a super-human intelligence, your're probably right. If you mean an expert system or neural net that is hard-wired for some specific task--such as extracting energy from chemical fuels--then you are provably wrong. What do you think a mitochondrion *does*? >Second, I think nanotechnology is bogus, because I think >that energy requires finite space. I believe that there is >a fundimental volume that an "electron volt" must occupy in >order for it to be stable and not dissipate. I think that >dreams of embedding enough energy for self-duplication in >something th size of a mitochondria is possible, because, >after all, that's what mitochondria have spent the last >billion years of evolution learning how to do. However, I >do not think that humans will ever be able to construct >anything smaller than a mitochondria that is still capable >of self-duplication and still have energy left over to do >other things -- like, run an "AI" program. Absence of evidence is not evidence of absence. However, even if evolved biolife does represent the best intelligence/volume ratio that can ever be obtained, that's still VERY impressive compared to our current technology. I think most people would without any hesitation call a demonstration of such human-developed technology a complete vindication of what Drexler says about AI in Engines of Creation. But then, we can ALREADY make artificial compuational elements, analogous to neurons, that have a much better intelligence/volume ratio than natural neurons do. >Finally, I think nanotechnology is silly because all of the >very-very-very-small logic gate technology I've read about >seems too Newtonian-mechanincal and not very well grounded >in quantumelectrodynamics that form the laws of nanophysics. Nanomachines do not necessarily need to restrict themselves to mechanical computational mechanisms. Quantum-molecular effects are being explored right now today as a basis for logic devices. The physical POSSIBILITY has already been proven. What remains is the engineering of practical devices. I make it my business to keep up with what's going on in all fields of science and technology. Unless you do this, you cannot see the whole picture, and you will tend to underestimate what is and will be possible. The other point I want to stress is to READ ENGINES OF CREATION!!! I get the impression that many people who pontificate on nanotechnology haven't even read this book. Shame on them! 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. ______________________________Down with Li Peng!________________________________ Motto: If nanomachines will be able to reconstruct you, YOU AREN'T DEAD YET.
arshad@lfcs.edinburgh.ac.uk (Arshad Mahmood) (06/29/89)
Silly ideas incorporated presents -> In article <Jun.24.01.04.41.1989.23818@athos.rutgers.edu> James.Price.Salsman@cat.cmu.edu writes: > > >Why I think Nanotechnology is Bogus. By James P. Salsman. > >First, I think nanotechnology is bogus, because I think that >information requires finite space. >I believe that there is >a fundamental volume that a "bit" must occupy in order for >it to be stable as a memory cell. I think this depends very much on whether you want to model current Von Neumann style computers in Nanotech terms, I suspect that we'll have to change our views on what we mean by computers as Nanotech offers us an unparalleld ability to build things of fiendish complexity with almost absolute precision. For instance we may see the blurring of the distinction between processor/memory. For instance can you imagine a molecule embodying a complete operating system ! If we could describe such a thing then, nanotech would allow us to build it (cf Eric Drexlers nanotech version of babages analytical engine). > I think that dreams of >embedding a typical "AI" program in an object the size of a >mitochondria is silly. I don't think you've come to terms with what nanotech can do, and the size of the potential machines we can build. > >Second, I think nanotechnology is bogus, because I think >that energy requires finite space. I believe that there is >a fundimental volume that an "electron volt" must occupy in >order for it to be stable and not dissipate. I think that >dreams of embedding enough energy for self-duplication in >something th size of a mitochondria is possible, because, >after all, that's what mitochondria have spent the last >billion years of evolution learning how to do. However, I >do not think that humans will ever be able to construct >anything smaller than a mitochondria that is still capable >of self-duplication and still have energy left over to do >other things -- like, run an "AI" program. What do mean by dissipate at these levels. Sources of energy for these machines were discussed a while back. > >Finally, I think nanotechnology is silly because all of the >very-very-very-small logic gate technology I've read about >seems too Newtonian-mechanincal and not very well grounded >in quantumelectrodynamics that form the laws of nanophysics. Have a look at the stuff done at Texas Instruments (also in a recent issue of BYTE where Eric Drexler's machine is also described). Of course there is some real work being done on Quantum Computers (David Deutch), but most of it is very controversial (ie are you compfortable with Everret's Many Universes Interpretation) > >Sorry if this is harsh, but I'm trying for constructive >criticism. Not at all ! A. Mahmood Laboratory for Foundations of Computer Science Edinburgh University Edinburgh -------------------------------------------------------------------------- Disclaimer: I never believe what I say
davis@att.att.com (07/04/89)
[Pre-background: I received an earlier letter from Paul stating that he considered nanotechnology bogus because we do not understand protein folding. I challenged him to provide credentials to back up such a claim:] Background - BSc (first class honours/summa cum laude) Biomolecular Science, Portsmouth Polytechnic, UK Post-graduate fellowship at Weizmann Institute (Biopolymers) with Prof. E.N. Trifonov working on DNA sequence/structure relationships Pre-doctoral fellowship at European Molecular Biology Laboratory, in Biocomputing, examing the role of hydrophobic clusters in protein folding. Chris Sander, Patrick Argos and others in this group are all heavily involved in protein folding research. Further Comments [I pointed to work at DuPont which I claimed was the beginning of a general protein synthesis technology] I can't claim to have seen the work from DuPont, and in this sense my next comment is a little foolish - I don't believe it, at least not your description of it. Why not ? Consider the instance of the so-called TIM barrel, a colloquial term for the structure adopted by, amongst other things, the enzyme TIM (tri-isomerase-i-forget-the-rest). There are at least 5 instances of the TIM barrel, and even the best sequence homology algorithms cannot identify the commonality in the sequences of the proteins that adopt this fold. On the other hand, there are several proteins with highly homolgous sequences which fold into totally different conformations. We have a very vague notion of what sequences might be good at forming some elements of primary structure (helices, beta-sheets), but even that is subject to a cautionary clause invoking the environment (the solution, the rest of the molecule) as major agents in facilitating or preventing such structures from forming. We have basically no idea (unless you wish to include lunch time discussions as "ideas") how these primary elements get juxtaposed to form tertiary structure, let alone what the actual process of folding involves. To the best of my knowledge, which isn't saying much, all the work that has been done on modifying sequences to produce new proteins has essentially operated on primary structure and maybe a little secondary structure guesswork. We simply don't know the effects of changing particular amino acids in a protein to something else. I think that the optimism you are seeing in the scientific press is misplaced at this time. Work is being done, and progress is being made, but to imagine that what we know now can form the basis of a sophisticated range of molecular engineering techniques is a mistake, in my opinion. [I compared a natural genome to an operating system and said that right now we knew how to write a bubble-sort] As for the genome/OS comparison, I consider this a little fallacious too. What we know for sure about the genome so far is really only the genetic code itself. Some of my research work was concerned with trying to elucidate other "hidden" functions in DNA - based on the work of people like Trifonov, Claverie, and the Cambridge MRC group, who have begun to show that DNA sequences really do very much more than code for proteins, and are actively involved in defining the structure of the DNA itself. This in turn affects the binding of proteins to DNA which modulate its function, a highly complex procedure which we can only sketch right now as a general case (some specific instances, such as that of POLIII are better elucidated). If you want a computer-based analogy, I would suggest our current level of expertise with the genome as similar to knowing what sequence to punch onto a paper tape, but having almost no idea what shape the paper should be, how to build a reading system, or what the feeback implications of the whole setup might be. In short, we don't know very much. I have a feeling that genetic engineering and nanotechnology will forge ahead despite this ignorance, and may even help to dispell some of it. But it will not do so based on any real understanding of biomolecular systems, and as a result is likely to take many wrong turns, and possibly even be dangerous. And as a final question, I would ask this of all nanotechnologists, biomolecular and genetic engineers everywhere - WHO NEEDS THIS STUFF ? We have enough fascinating games to play already without molecular building blocks, and the problems of our world are political, social and psychological rather than technological. Nanotechnology, like the computers I use everyday,is just another toy for those of us who seem unable to accept what is, who can't the fact that there are simpler but more difficult decisions and choices in our world that will make us happier, healthier and more at ease with our world than fiddling with molecules, be they galium arsenide, proteins or DNA. If you can declare it as a toy, then great - but I don't want to play. Please don't tell me what a wonderful world it will bring - the world is already wonder-full enough for me. Paul [The Update gives a reference to DeGrado (ie the DuPont stuff) as Science 241:976-978 (19Aug88). I would have sworn I'd seen something later than that (also in Science) but I can't find it in the top few pitchforkfuls of my "files". I fear I wasn't specific enough in my description, however. The critical distinction is between science and engineering. Consider building a bridge. If you leave no margin for error, and the traffic gets heavier, it is impossible to predict on just which bounce of just which car the bridge will break, and just where every piece will fall. However, it is not impossible at all to design a bridge that won't break in the first place. Complicating the scientist's task in studying natural systems is the fact that these systems tend to operate near the edge of workability--that's the way evolution works. The engineer, including the molecular engineer, has the luxury of avoiding the structures he doesn't understand; the scientist doesn't. Of course the engineer needs to understand enough to have a "working vocabulary", but this can be a much smaller set than appears in a natural organism. The engineer's motto is "anything that works," but evolution's motto is "everything that works." As to the final paragraph, this seems a matter of personal perspective, and you are certainly entitled to your opinion. However, I really think that the statement "the problems of our world are political, social and psychological rather than technological" is unconsidered. There are not "social" vs "technological" *problems*, but rather social vs technological *solutions*. In my reading of history, social and political solutions *do not work*, but the problems technology has been applied to have been decimated. I further claim that the technological solution to the problems you are worrying about is to make human beings more intelligent; nanotechnology is a plausible approach. --JoSH]
alan@oz.nm.paradyne.com (Alan Lovejoy) (07/07/89)
In article <Jul.3.21.57.38.1989.5072@athos.rutgers.edu> mtgzz!davis@att.att.com writes: >[Pre-background: I received an earlier letter from Paul stating > that he considered nanotechnology bogus because we do not understand > protein folding. I challenged him to provide credentials to back > up such a claim:] The fact that we have not solved the protein folding problem in no way proves that nanotechnology is bogus, even if it turns out that protein folding is inherently insolvable. At worst, it limits what can be done with nanotechnology. Of course, there are many useful things that we will be able to do even without a complete theory of protein folding. But it is not yet proven that a complete theory of protein folding can never be formulated. The dictum that "absence of evidence is not evidence of absence" is a sword that in this instance cuts both ways. > And as a final question, I would ask this of all nanotechnologists, >biomolecular and genetic engineers everywhere - WHO NEEDS THIS STUFF ? >We have enough fascinating games to play already without molecular >building blocks, and the problems of our world are political, social and >psychological rather than technological. >Please don't tell me what a wonderful >world it will bring - the world is already wonder-full enough for me. Speak for yourself. You may be content to age into ill-health, gray hair, baldness, incontinence, heart-disease, cancer, senility and finally death. I am not. I have a moral, ethical and legal right to life and health. And I have every intention of pursuing those rights to the fullest, even if I have to make the Jeremy Rifkins of the world unhappy. Your attitude reminds of the eco-freaks who think we should emulate the Amish and return to the eighteenth century technology that God ordained for us. Bullshit! 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. ______________________________Down with Li Peng!________________________________ Motto: If nanomachines will be able to reconstruct you, YOU AREN'T DEAD YET.
macleod@drivax.UUCP (MacLeod) (07/07/89)
: ...However, I really think : that the statement "the problems of our world are political, social and : psychological rather than technological" is unconsidered. There are not : "social" vs "technological" *problems*, but rather social vs technological : *solutions*. In my reading of history, social and political solutions : *do not work*, but the problems technology has been applied to have been : decimated. I further claim that the technological solution to the problems : you are worrying about is to make human beings more intelligent; : nanotechnology is a plausible approach. : --JoSH] I think Buckminster Fuller put it most succinctly: "Don't try to reform man; reform the environment." Michael Sloan MacLeod (amdahl!drivax!macleod) [Buckminster Fuller also designed a car shaped like a fish, with reverse tricycle stance. In general, today, his maxim is correct, however. This simply reflects that technological solutions work, socio-political ones do not. "Making people smarter", by the way, does not *necessarily* mean going in and twiddling with their brains. Hypertext publishing systems and fact fora are a start toward smarter people, in the sense that they are more likely to make the right decisions. Computer link implants, expert system encyclopedias, etc, etc, etc are steps on the way. --JoSH]