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Nanoscale tech vs. Mechanosynthesis

from the terminology-drift dept.
Cryptologist Hal Finney points out on the Extropy mailing list that Foresight's views of molecular nanotechnology are still not generally accepted, despite all the funding of "nanotechnology". Read More for his post. Yet there are a few brave researchers who take self-replication via nanotechnology seriously in public; see the end of this interview with Harvard's Charles Lieber in The Deal: "There really are some fundamental scientific problems where you can end up creating self-replicating things and invading bodies, but I don't worry about that at this point." He's right not to worry that this might happen soon. However, since it is a possibility, some of us are putting time into thinking about it in advance — it's a tough problem to head off, and figuring it out will take some time. Hal Finney writes:

A couple of years ago, Foresight essentially declared victory in the war for acceptance of nanotechnology. There were conferences held every year, one or more respected journals, government funding was ramping up, articles in business journals. By all accounts it was now an accepted future technology.

But maybe that was premature. We are seeing a backlash, a rearguard fighting action against the original vision of nanotech. Opponents are trying to build a firewall against Drexlerian mechanosynthesis, drawing a distinction between their prosaic nanotech and Drexler's far-out visions. They prefer to focus on biotech, on nanoparticles, on MEMS, on bulk materials engineering at the nanoscale. All these things can be done today, in fact they are the natural consequence of existing technologies just extending their capabilities a bit. They want to get funding for their current research. In this environment there is no reason to even think about blue sky dreams like eternal perfect health, or nightmares like engineered malignant replicators.

I think Foresight needs to go back to its roots and shore up the foundations. It's not enough to have "nanotechnology" initiatives showing up everywhere. Few of those efforts are making significant progress towards Drexler's machine-based models. Foresight needs to remind people that there is more to nanotech than making ultra-fine powders for smoother paint. We have to keep our eye on the prize, a technology which can utterly revolutionize every aspect of the world. If research is not moving us towards that goal, it should not receive funding under nanotech grants, even if it happens to involve little tiny pieces.

20 Responses to “Nanoscale tech vs. Mechanosynthesis”

  1. CraigHubley Says:

    GlobalGreens also taking replicators seriously

    Another group taking it seriously is the Global Greens, who have had some discussion about creating a common policy on artificial life. And noted that the Foresight Guidelines have already been violated.

  2. RobVirkus Says:

    Recent Retreats

    It is one thing to take self replicating assemblers seriously (I do) and another to take some of the implications seriously. I think many people have quite a strong reaction to claims such as restoring youth, perfect health and resurrection from the dead (at least from the frozen). This is natural and expected. But the recent press such as Scientific American which questions the core assembler idea may not be as dire as I first thought. Consider that most of the main focus was the Assembler whether for or against, leaving the reader at least thinking that the debate is still ongoing. Will most readers believe Smalley and Whitesides rather than Drexler? Probably not. I say this because it is natural not to want to let the idea go away when one realizes its potential. The education process does need to move forward but it may be wise to focus on Assembler feasibility and its manufacturing implications rather than on the medical aspects which are less certain. Just as no rational person can now deny that molecular electronic devices can be made it will take a few minor steps in the Assembler direction to make people see. A helpful step in the meantime may be a wider range of plausible scenarios for an Assembler and more use of correct technical language to describe them as compared to the poorly thought out characterization which Smalley attacked in his Scientific American article.

  3. RobertBradbury Says:

    Climbing the mountian

    One of the major problems is that very few people have read the literature necessary to discuss the problem from an "informed" perspective. Given the rapid rise and fall of the .coms, many people, especially the VCs and many private investors who got burned are afraid of a repeat. Hal said, "We are seeing a backlash, a rearguard fighting action against the original vision of nanotech." This is to be expected. Given the full vision people will have to give up two universals that have been with humanity for thousands of years, (a) that shortages will always exist; and (b) that death is "inevitable". If people really understand the full vision, many will grasp at any available reason to maintain those long-held beliefs.

    The second part of the problem is that in our discussions we get sloppy in our terminology and that confuses people. One example is linking the terms "self-replicating" and "assembler". For example, Rob said, "It is one thing to take self replicating assemblers seriously (I do)." Whitesides made a similar linkage in his article. It is not necessary for assemblers to be self-replicating! As Whitesides pointed out, to do anything useful with an assembler you need a lot of them. But as Hall pointed out in 1999, here, it would be much faster to have an "assembly line" of assemblers producing nanomachinery (including parts for more assemblers). Anyone who has seen the Zyvex presentations at the Foresight conferences the last several years knows that they are focused on "exponential assembly", which is quite distinct from "self-replicating assembly". One way to minimize some of the fears regarding things like "grey goo" is to point out that if goo were easy, nature would have already evolved the green variant of it. Many, if not most, classes of organisms that can make copies of themselves, are not really fully self-replicating because they require parasitic relationships with other organisms to supply them with various materials they require for replication.

    We need to learn the terms and use them accurately.

    There is nothing wrong, IMO, with focusing efforts on biotech. We have assemblers there now and many sets of complete blueprints for self-replicating systems and molecular scale machinery. Biotechnology does provide the wet path to mature molecular nanotechnology (in contrast to the AFM based dry path).

    Foresight could certainly help by working with governments, academics and VCs by pointing out the long term advantages, esp. on the medical front and educate people on the paths to getting there. If the funding sources had a clearer understanding of the problem (e.g. Chapter 16 of Nanosystems), and were working concretely towards the "generations" of assemblers in Table 16.1, then people might begin to understand how one can develop from our current level (precise chemical synthesis of molecules of a few thousand atoms), to assembler arms with millions of atoms, to nanorobots with billions of atoms. The way to remove the hype and keep the hope is to make the path clearer to people.

  4. RobVirkus Says:

    Re:Climbing the mountian

    What Robert referred to a the "full vision" is part of the problem in my view. As a vision its fine but as a scientific goal it is not. We should separate the technical goal of assemblers, self-replicating or not from talk such as whether "death is inevitable" or not. Assemblers simply look less credible when discussed in the same breath as cryonics. I know that is not fair but I think the goals have been slowed by the linkage in the minds of critics. In my previous statement which Robert quoted, the distinction between self- replication of assemblers was not at issue. The linkage of assemblers with the vision of animating the frozen was. That leap makes the whole vision suspect to the critics. That was my point. It showed up on several pages of the Scientific American issue. I fear that some Nanodot readers do not see that such ideas are the hype many scientists react against. Then they can't get beyond to a reasonable discussion of the technical merits of assemblers leading to Molecular Manufacturing which is on more solid ground.

  5. RobertBradbury Says:

    Re:Climbing the mountian

    I'm not sure one can separate the vision from the goals. Surely the demonstration of atomic fission was necessary on the path to a sustainable nuclear reaction for atomic power. In any discussion where there are lives at stake, as there are in most Foresight discussions, it is reasonable to discuss whether playing the hand openly or slyly is the best strategy.

    So one might ask whether the sly approach, of not openly discussing the "full vision", would reliably accelerate the development of robust molecular nanotechnology, such that more lives are saved than the open approach, of disclosing the "full vision", such that open minded individuals will adopt methods, such as cryonics, that may save their lives? In my mind this invokes the classic "Spock dilemma" of whether "the needs of the many, outweighs the needs of the few".

    Assemblers do not look "less credible" when discussed in relation to cryonics. DNA polymerase and the ribosome are existence proofs that "assemblers" are feasible. DNA and protein synthesizers are proof that humans can construct "equivalents" to such machines on a larger scale. Any scientist who objects to the concept of assemblers has an extremely limited concept of biology and the current state of human technology. So "assemblers" are proven — it is the concept of "general purpose" assemblers remains open for debate. Expending energy discussing specific-purpose assemblers with scientists who are not sufficiently educated is presumably time poorly spent unless you are being paid to educate them (many physicists and chemists may be unaware of these "facts").

    The concept of "cryonics" is similarly proven. I believe the last report I read on the subject documented ~30 human cell types that had been frozen and revived successfully after freezing. There are at least tens of thousands, perhaps millions of people walking around the earth today who were manufactured from frozen cells. Experiments with stem cells suggest an extensive capability to regenerate tissues and organs from these cells, presumably even after freezing. So the feasibility of post-cryonic revival is increasing, all the time, using biotechnology alone, even without molecular nanotechnology! As with assemblers, there are still questions as to whether "general purpose" reanimation of entire complex organisms following cryonic suspension is something that can be achieved.

    So the only point that would seem to be served by not including the discussion of "cryonics" several chapters removed from "assemblers" is one of "political correctness". Following a "politically correct" path might allow increased comfort for conservative scientists and could potentially accelerate the realization of robust molecular nanotechnology — but it may do so only at diminishing the awareness of real potential solutions that may currently be available. Given the moral tradeoffs involved, such decisions should only be made in a full disclosure environment.

    The linkage of assemblers with the reanimation of the frozen isn't one that should be lightly glossed over. The reassembly of proteins and lipid membranes damaged by freezing damage may require assembler level technology. The Shermer article that showed up in Scientific American, is presumably based on the Summer 1992 issue of The Skeptic. Unfortunately, this was before the 1994 article, "The Molecular Repair of the Brain" by Ralph Merkle, documenting how reanimation may be accomplished. In Shermer's article I see no evidence that he has even read Ralph's article (or is even qualified to judge its technical merit). Shermer himself acknowledges, "This is what I call 'borderlands science,' because it dwells in that fuzzy region of claims that have yet to pass any tests but have some basis, however remote, in reality". Shermer's view is obviously slanted, but is it reasonable to allow physicists to suggest that fundamental constants in the universe to change over time (as has recently been the case) but disallow bioengineers from suggesting that frozen human bodies may be reanimated?

    Every time you allow yourself to step onto the slippery slope of "slyness" over "openness", IMO, one is admitting defeat. You are accepting that it is ok for scientists to express opinions that are based on incomplete understandings of the published literature or you are catering to political correctness. You may be saving future lives at the expense of current lives. That is not blood I'm willing to have on my hands unless a reasonable argument can be presented to justify it.

  6. RobertBradbury Says:

    Re:Climbing the mountian

    Minor correction, though Shermer's Scientific American article mentions Ralph's article, there is little discussion of technical objections. So there is argument that the "sin of death" cannot be erased without any technical arguments as to why nanocryonics cannot erase that "sin".

  7. RobVirkus Says:

    Re:Climbing the mountian

    Instead of "sly" I would say diplomatic, reasoned and responsible.

    Let us agree that we are not talking about natural biological based assemblers but artificial assemblers or any such artificial system which results in the Drexlarian vision of the general ability to build from the bottom up with the resulting products having precise atomic specifications or near so to the degree specified by the designer- of course I am talking about the "general purpose". The feasibility of such assemblers rests on solid science. To then mix solid science with more speculative assertions can cast doubt on the whole enterprise. If you want to spread the assembler meme why not take into account human nature regarding the acceptance of new ideas? There are places to discuss cryonics and places to discuss assemblers. Let us use discernment. They are not perceived as and are not actually equally credible ideas (in my view). Would you bring up cryonics in a grant proposal for work which may lead to some from of assembler? That is one test. If not to the grant committee why raise it to the general scientific community? Work which leaves no doubt about assemblers (like the recent work which leaves no doubt about molecular electronics being feasible) will naturally lead to a broader discussion of the implications. Then the cryonics debate can be open. Again, I think it is not about being "politically correct" but using sound judgment and wisdom in spreading extremely powerful ideas.

  8. RobertBradbury Says:

    Re:Climbing the mountian

    Being "diplomatic" may be the proper way to win grants and good scientific debate is hopefully "reasoned", but the "responsible" path for the development of robust molecular nanotechnology is precisely one of the things the Foresight Institute should be focused on. Is it "responsible" for the best experts in the field who have studied the problem to defer discussion of cryonics when it may very well save lives? You might argue that is the case, but you have to make a very strong argument that doing so will accelerate the development of robust molecular nanotechnology significantly faster than would otherwise be the case and make the case that the value of potential future lives saved significantly exceeds the value of current lives saved.

    I choose not to separate the discussion of biological assemblers from general purpose assemblers. We have biological assemblers now. We also have evidence that enzymes can assemble complex molecular structures, e.g. taxol, now. We have a number of companies actively working to design or evolve enzymes with enhanced capabilities, now. We have no demonstrated experimental evidence that general purpose assemblers for diamondoid, sapphire, titanium carbide or even more complex CHON materials with significant bond strain are feasible. The phase space of what might be assembled using biological assemblers may be significantly smaller than the phase space of that which general purpose assemblers might assemble but at this time we have no way of knowing how much smaller. I look around at the blueprints for natural molecular machines that are available and the lack of blueprints for human designed molecular machines and would say that finding ways to leverage the investment that natural evolution has already made puts us significantly ahead of the game. Utilizing the existing design base and assembly methods follows your suggestion of minimizing the reluctance to accepting new ideas.

    Using discernment, one would point out that the Shermer "anti-cryonics" idea was based on the concept of freezing plant cells which are significantly different from animal cells and that no protection from freezing damage was used. Is that "reasonable" scientific debate? Reasonable debate would point out that over several decades our ability to freeze and recover the function of dozens of mammalian cell types has been developed. Reasonable debate would require that instead of people composing poor analogies they actually read the literature and point out specific flaws in the proposed methods.

    Discussing cryonics in a proposal for assemblers presumably makes little sense — but the Foresight Institute doesn't write grant proposals for constructing assemblers. It does advise Angel and VC investors who may find the possibility of surviving the curtain of death appealing. I personally knew two extremely wealthy individuals who invested significantly in drug companies developing anti-cancer treatments when one of them was faced with a terminal cancer diagnosis. That individual, now deceased, might still potentially be with us had there been greater discussion and scientific acceptance of the concept of cryonics. I knew two other moderately wealthy individuals who suffered accidental deaths in conditions that would have been close to ideal for cryonic suspension. Avoiding the debate because it is "distasteful" to the conservative scientific community costs people their lives.

    One does not raise the discussion of cryonics to grant approval committees because it is unlikely to be highly relevant to the purpose of building assemblers. One does raise the discussion of cryonics to the general scientific community because if more were convinced of the feasibility it is highly likely that lives would be saved because fewer would be making claims that it was practicing "quackery". One does raise the discussion of cryonics with investors because most of us have lost people whom we feel close to and have felt relatively powerless to do anything to stop that. Cryonics combined with molecular nanotechnology potentially provide the means to reduce the probability of future instances of those feelings. The promise of molecular electronics for better computers or diamondoid materials to allow us greater access to space are certainly fine goals — but it is the promise of biorobots and nanorobots and cryonics — the things that will actually save human lives that motivate my interest in molecular nanotechnology.

  9. brianwang Says:

    Re:Climbing the mountian

    I think that VC's have an understanding of the scaling issues to go from AFM and other current low volume nanotechnology to go to building macroscopic objects from nanotechnology. I believe Jurvetson does based on discussions and his talks at Senior Assoc gatherings. I think the huge gains from being able to scale will drive research and business towards the best solutions. (self-replication, exponential assembly, highly parallel lasers, …)

    The rearguard action is irrelevant to achieving what was envisioned, because it does not change the current or the incremental research and design choices and improvements that are being made which will lead to full-blown molecular nanotech. Those who believe and act upon the rearguard statements would not have understood, accepted and acted towards achieving a future with full-blown nanotech.

    What the rearguard action does represent is the entrenched views, activists and political forces that believe and act on the belief that shortages exist and death will always happen. They will change their views some months after molecular nanotechnology is used to produce nearly all products and is used in medicine. Social policy changes will be and has been hindered by this lack of willingness to plan with correct assumptions.

    Technology advances continue to be made:
    -nanotech assembly gets faster and more accurate
    -more intermediate designs are made towards achieving full-blown assemblers
    -there are intermediate products and industries that will drive large scale investment (moletronics, carbon-nanotube products will be multi-billion dollar industries)

    I see no indication or danger that people will stop with ultra-fine paints and powders.

    Social policy change and institutions are currently reacting to advances in cloning, genetically engineered medicine and agriculture and stem cells. Foresight can tell them about what to expect from nanotechnology, but I think the baseline expectation should be one where they turn to Foresight for advice after the fact. Foresight should still help make the paths more clear and detailed. Foresight should continue working with those who are listening and making the future happen. (VC's, military planners, Zyvex, etc…)

  10. jbash Says:


    You know, if I hear this silliness about nanotech somehow eliminating scarcity one more time

    Look, folks, matter and energy are conserved. There is only so much to go around. Nanotech does not change that. Don't start running on about space, either… the available resources are, at best, what you can get inside a shell expanding at the speed of light.

    Yes, you can get more efficient and do more with less. Probably vastly more with vastly less. No, you do not get infinite resources.

    There will always be scarcity of some kind, unless you can guarantee that:

    1. Individual people's desires don't increase without bound, and
    2. People don't reproduce without bound

    If you like, you may substitute "resource consumers" for "people" in the above.

    It may or may not be possible to get those two conditions. I'm especially pessimistic about the second. One thing I'm really sure about is that nanotech, unless you apply it to mind control, isn't going to be what gets you either one.

    And, as long as I'm ranting, the idea of living forever is dumb. Living a long time, sure. Living as long you might even want may be feasible. Living forever runs into that little issue of the heat death of the universe. Not that living forever is necessarily very desirable anyway.

    Even if you know that you're being hyperbolic, talking about "unlimited resources" and "living forever" makes you sound like some kind of loony cultist.

  11. RobertBradbury Says:


    Yes, of course there are limits. I've written several papers on exactly how fast one might expect to expand on the physical level as well as the limits at the computational level over the last 3 years. The concepts behind Jupiter Brains and Matrioshka Brains are that there are some really hard limits unless a transition to subatomic engineering is feasible.

    With regard to the points raised. It is already clear that it is difficult for desires to increase without bound unless the entity having the desires does so as well. There are limits where even the richest people in the world realize that owning another car or owning another house is pointless. The desires move into the realm of what does not yet exist, and then the difficulty bringing of those things into existence regulates the rate at which resources are consumed. It is completely obvious that unlimited reproduction is impossible. The universe is finite. Here on the Earth, the developed countries are below the replacement reproduction rate. So it is seems questionable whether in populations where the survival of the individuals is relatively comfortable and approaching natural longevity limits whether populations would continue to grow. [It would be interesting to determine why this is the case -- does humanity have a "self-extinction" meme?] For those interested in this topic, there is an interesting societal approach to this problem in Tom Kirkwood's "The Time of Our Lives".

    "Rational" thought may be what gains you the ability to regulate your desires and your reproduction. Certainly an issue that nanotechnologists and people associated with the Foresight Institute should be concerned with is what to do about vectors that would generate machines, robots, AIs or humans that function to increase "irrational" thought! As the vectors in the genomic and biomedical industries are in the direction towards increased therapeutic control over our unconscious "drives", the direction for humans should currently be towards increasingly rational behavior. So I agree that nanotechnology itself does not prevent shortages. Only rational behavior in light of the architecture of the universe may manage that feat.

    "Living forever" (for informed people) is the short form of saying "Living until the laws of physics prevent it". Dyson has written a paper on how to survive the heat death of the universe [1]. Whether that will be feasible depends in part on whether protons decay which is currently undetermined. I personally would view living forever "unproductively" as a relatively pointless exercise. But to the extent that I can use the resources available in a productive fashion, I would enjoy doing so. That might suggest a metric by which one might evaluate worth the results of expanding or constraining the resources available to individuals. I would stress the problem of using the "prevailing wisdom" in evaluating the worth of the "productive use" of resources. History would show that it is often the most radical ideas that produce the most significant breakthroughs, so one must be very careful in the development of such metrics.

    If I sound like a "loony cultist" it is because you may lack the knowledge of the information base I am working from, or knowledge of that information base. If I am using terms such as "unlimited resources" or "living forever" freely in ways that they may be misinterpreted, I apologize. People who take the trouble to explore my background would understand that I mean "relatively" unlimited resources and "potentially" living forever. That is why "reputation analysis" is an important part of reviewing anything one reads on a public news system (or in a newspaper or journal presumably). You have to know how to value the comments of an individual so you know how much value to place on their assertions or statements. I apologize if my previous statements could be considered "misleading" as I was trying to balance the discussion between people who might be familiar with my perspective with those who might be unfamiliar.

    1. "Time without End: Physics and Biology in an Open Universe", Freeman J. Dyson, Reviews of Modern Physics, Vol. 51(3):447 (July 1979)

  12. RobVirkus Says:

    Re:Climbing the mountian

    I consider cryonics to be a separate field. Used as an argument to win support for money and minds to bring about molecular manufacturing or medical nanorobots it seems to turn serious minded people away. Motivation from medical possibilities for the living are appropriate. It is premature to assert that lives will ever be saved by cryonics. That is a matter of faith. It is in effect a religious assertion. It amounts to a technical version of Pascal's Wager i.e. it is more rational to believe in cryonics because it might work that it is to not believe it because it might not work.

    "- but it is the promise of biorobots and nanorobots and cryonics — the things
    that will actually save human lives that motivate my interest in molecular nanotechnology."

    Great. And for me it is the promise of meeting material and medical needs and the challenge of the technology which holds my interest.

  13. farlops Says:

    Don't worry, let the definitions blur

    I'm not really that worried about the venture capitalists, ambitious scientists or government functionaries selectively blurring distinctions or misapplying definitions.

    The reason is that a lot of the things that are getting this new surge of funding can still tie into nano, even though they are not directly related. For example, the principles learned in making replicating MEMS can still apply, in general, to replicating nano assemblers. Research in bio-engineering can still tell us a lot about how to restrain dangerous replicators. Much, though not all, of this knowledge will not be wasted once the real assemblers are built.

    It is true that opportunists looking for money may slow down deserving research but this has always been a problem. Think of it as a useful breaking system inherent in the process of scientific and technical research.

    My real worry is the question of open research. I don't want the various militaries of the world to disappear into secret labs with this stuff.

    Another of my worries is security and quality taking a back seat to profit, citing Microsoft (Or name your favorite corporate baddy.) as an example.

  14. LSMcGill Says:

    Re:Climbing the mountian

    This one's one I'm not sure which way I'd swing, because at it's base, it's a debate for ends justify the means, i.e, tailoring a Nanotech pitch to downplay the "hype" vs. an open approach where all the cards are on the table.

    I'm don't think I can fully agree with either side, becuse while I favor the open approach, I don't feel the majority of Nanotech researchers have really told the general public the *full* potential of MNT, because there are many aspects of it they find disquieting, but at the same time, I can rationalize selling MNT on the basis of what it can do for the individual, not on what it could mean to humanity, but what it could offer *you*.

    Face it, we all support MNT for what it offers to *US* personally, not what it offers to humanity. We want what Nanotech offers that nothing else does.

    In the end, that may be the best way to sell it the world at large. Tell them what it can do, everything it can do, for each and every person. Show that it has such a broad appeal that everyone can see what advantages it has for them, and maybe, it will stop being the esoteric playground of the few who have bothered to understand what it really means.

    Because if you can build a widespread public demand for MNT, you'll get the funds in nearly unlimited amounts.

  15. LSMcGill Says:


    Humm… Personally, I look at it from this perspective. The Average life expectancy is based on a figure that assumes two invalid points. One: That during my lifetime, I will recieve medical care no better than my grandparents recieved. Two: That during my lifetime, medical science will not improve. Both are false assumptions and not readily appearent. I don't make general statements about an end to scarcity, or immortality, but like most predictions of the future, it seems both side are again making a fundimental assumption. That technology and science will not improve beyond what we currently know. I won't make that claim, not now or ever. I could take what we currently have today and create a world you'd never recognize, and that's if research came to a complete halt. To make assumptions about what the future science will be beyond 10-30 years is pure hubris. Superstring theory may make a way to create matter from pure energy, or create wormholes that cross universes. I don't know, it may amount to yet another idea on the junk heap of history, like philogston. Anyway, it's too early to say what the future will bring with certainty. Scarcity may truly be a thing of the past once the breakthrough comes. Best to keep an open mind.

  16. MarkGubrud Says:

    My assessment

    The basic problem is that Drexler's popular writings made it sound like progress toward assemblers would be straightforward, that people would start picking up atoms with STMs and building things, bigger and bigger things, and after a few years they'd be building machines, and then assemblers, and then the assemblers would be self-replicating, and then Wham! I know, I know, this impression would have been dispelled by a more careful reading, which would have found lots of caveats. But it is the impression that came across to many people, and it led to a lot of cargo-cult activity anticipating the imminent arrival of "the assembler revolution." I think this is what the scientist critics were reacting to with their blanket dismissals.

    By now it is clear that nanosystems at the level of self-replicating assemblers are a very distant goal; in fact, we cannot be certain at this point that the goal will turn out to be feasible and cost-effective in practice, although there is still no good reason to doubt that it is physically possible and ultimately achievable.
    There is no doubt that we can ultimately create some kind of "artificial life" which self-replicates and can be programmed to make products in a wider range of materials than those of natural life, and which realizes much of the potential described in Drexler's popular and technical publications.

    But it is not at all clear how soon such a technology will be realizable, nor exactly what form it will take. In particular, the case for the Drexler/Merkle diamondoid technology has not been proven nor has it been made in a fully persuasive form. Although simulations show that diamondoid nanomachine systems can work, they have not shown that all of the steps needed to fabricate such systems by direct mechanosynthesis can be carried out. We have not seen any simulation of a self-replicating assembler system going through a full cycle of self-replication. Such a simulation, even if carried out at a low level of accuracy, would go a long way toward dispelling skepticism that the technology is feasible.

    When I asked Eric about this recently, he said that his "engineering intuition" told him that all the necessary steps could be carried out by assemblers of the type he has designed. I'll take that at face value, but admit that my own intuition falls short of such a conclusion. More importantly, such a response does not pass muster in the scientific world. I can say, for example, that my intuition tells me that noninvasive molecular-scale mapping of the brain, as required for "uploading" without killing the subject, is impossible, but without giving a detailed and specific technical analysis of why I think this is so, I can't reasonably hope to settle the debate with people like Ray Kurzweil who assert that this is not only possible but likely to be achieved within a few decades.

    The bottom line: Nanotechnology is already a reality, and there can be no doubt that it will lead eventually to complex nanosystems with the capablilities of life and more. However, we do not know how quickly progress will be made, and we cannot regard the case for diamondoid assembler systems as proven.

  17. LSMcGill Says:

    Re:My assessment

    I've always thought non-invasive synaptic mapping could be accomplished by S.Qu.I.D.s of sufficent resolution joined to a computer with enough complexity and memory to record and interpret the data. Would not require even opening the skull and also contains the possibilites of providing interface possiblities for VR in the short term.

    As for the creation of self replicators, your very existance argues for the feasibility, but does not prove that they can be manufactured of the materials proposed by Drexler. His proposal is based mostly on the concept of carbons utility for creating the structures and the availability of it for inexpensive construction. There is also thye possibility that due to it's use in organic chemistry, it might be possible to modify existing bio-processes to make Drexler's structures. While Drexler's designs are unproven, he himself states only that they are *possible* and bases the rest of his findings on that assumption.

    I may not agree with the man's politics all the time, but I've not found anything too far fetched in his science.

  18. MarkGubrud Says:

    Re:My assessment

    As someone who currently deals with SQUIDs on a daily basis, I can assure you there is absolutely no way these devices can ever be used to map brain structure at the molecular level, particularly not remotely. Such a proposal does not even come close to plausibility. SQUIDs can be used to map brain electrical activity to millimeter resolution at best. This is good enough for some diagnostic and research purposes, but not for "uploading."

  19. Angel Says:

    Re:My assessment

    Ah… glad to have that cleared up. I did not know that, having a dearth of information on them beyond a William Gibson novel. Thanks.

  20. LSMcGill Says:

    Re:My assessment

    Indeed. I had thought they had better resolution than that. Shows what you get when you have a lack of clear detail. I had thought they might also be useful for a non-invasive VR interface. Angel and I have talked about them a couple of times since Johnny Mnemonic. Wouldn't mind better details?

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