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« He's Serious, Folks | Main | NNI FAQ Revised »

July 31, 2004

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todd

I not at all surprised to see articles disputing the feasibility of molecular manufacturing their many arguments to support their position if only from the standpoint of calming public fear. A government or leadership position one must consider many other factors notwithstanding the truth. The truth is molecular manufacturing is coming to timeframe and technique of the final design or designs as is likely there are more than a number of ways to produce the final useful product. It should be noted in the past this position has been taken by many reasonable and responsible groups when one was discussing airflight in 1900 one would certainly received a variety of arguments pros and cons once again if in 1940 was to discuss the atomic bomb one would receive a variety of pros and cons. Things are changing this is the only truth one can find in anything and with change comes either chaos or order throughout history we have seen either of these happen time and time again is my opinion at this point in time we shall try to stay calm to make rational decisions by to also recognize that no one country or organization can stop progress regardless of how many articles papers or books are written outlining how molecular manufacturing cannot be accomplished it will not change the flow of progress is interesting to note molecular manufacturing is not a single technology but made up of a group of technologies indeed almost all technology contributes to the eventual goal of a molecular manufacturing tabletop device i.e. "a wish box" I have spoken with many laymen and/or common man and attempted to explain the concept of a wish box and I received a variety of critical responses to the future. We cannot know the future but we can make honest and intelligent predictions in order to ease the transition from the old to the new. There is a commercial running on television it betrays a group of men sitting around a fire in the old day circa 1840 the one of the men points out a prediction for the future the other men laugh, the prediction is" in the future only children will ride horses ". Certainly to the laymen or common man of the time in 1840 the idea of not riding horse for transportation would be difficult to see. today in 2004 is equally difficult for the average man to see a future where building of a product or structure is as simple as imagining it trying a picture and hitting the print button. Whether the change is the transportation industry moving from horses to automobiles to aircraft to space craft or a new form of manufacturing moving from hands-on building to assembly line to robotics to molecular assembler the argument is the same the future will bring change and the changes are coming at an unprecedented rate every day literally tens to hundreds of small breakthroughs occur in labs at colleges and businesses and governments around a world. Contributing technology for the construction of the molecular assembler comes every day.

Brett Bellmore

Todd, good job on the punctuation. Now try paragraphs, and you'll be highly readable. Don't think I'm obsessive, but if something's difficult to read, many people will never reach it's merits. Sad, but true.

I think you've got a point, that people in established positions tend to dismiss the possiblity of major changes, which might upset the order they're on top of. But I don't think they're lying to shield the public, I think they're doing it to reassure themselves.

Philip Moriarty

Now that molecular manufacturing has been considered in some detail at a recent NRC Nanotechnology meeting , I thought that I'd revisit some of the comments posted re. the UK Royal Society's findings last year:

"And it claims that they've seen no peer-reviewed evidence that molecular manufacturing can work. It appears they didn't look very hard." Chris Phoenix.

...to which the hyperlink on "didn't look very hard" links to a technical bibliography on positional mechanosynthesis (discussed in detail here).

Chris' comment is typical of the frustrating, tiresome, and steadily increasing obfuscation underlying the Drexlerian position. Even Freitas (who put together the cited bibliography) doesn't claim that the work he cites provides evidence for the viability of molecular manufacturing. Instead, he clearly (though in some cases incorrectly) labels it as positional mechanosynthesis.

Let's try to cut through the fog:

- There is currently no experimental evidence for molecular manufacturing.

- A single demonstration of a mechanosynthetic step has not yet been experimentally demonstrated.

Elsewhere on the CRN blog, the following argument is made:

"If a Seeman-style machine could be made to build a complete duplicate of itself, that would be close to if not actually achieving molecular manufacturing."

Chris, just where in Seeman's work is there a demonstration of the computer-controlled positioning of individual molecules with atomic precision that is a prerequisite for the low level basis of molecular manufacturing? You might plausibly argue that Seeman's work could be seen as a stage in Drexler's 'backward chaining' approach towards molecular manufacturing but to cite it as a demonstration of MNT ("...if not actually achieving molecular manufacturing") is simply wrong.

It's clear from previous discussions that you like to treat some questions as rhetorical. The question above is not rhetorical - I'd appreciate a response.

Philip


Chris Phoenix, CRN

Seeman's machine is programmed by specific DNA strands. Those could be built and supplied by computer.

The machine does not select from among many similar deposition/reaction sites on a single molecular object. However, it makes reactions happen between selected molecules at a specific position (relative to the machine); those reactions don't happen elsewhere (among free-floating molecules).

If this is not mechanosynthesis ("Chemical synthesis controlled by mechanical systems operating with atomic-scale precision, enabling direct positional selection of reaction sites") then it is close to it. One could imagine a branched polymer built by a Seeman-like machine that added monomers to a selected one of the branches. That would constitute mechanical selection between similar reaction sites.

Objections to molecular manufacturing have depended for decades on strawmen: overly narrow or even nonsensical proposals, chosen and dismissed by the critics. MM is a lot broader than most of the proposals that have been criticized.

Now that discussion is turning away from rhetoric about the impossibility of self-building machines, and toward consideration of the actual proposals, the strawman style of argument will carry less weight. I'm sorry if this upsets you. But the current broadening of scope is not obfuscation; it is simply de-strawmanning the discussion. It should never have been so narrow in the first place. There will be continuing efforts to keep it narrow, such as Richard Jones's surprising statement that "hydrogen passivated diamond is by far the best candidate for a working material for mechanosynthesis." But I don't think that's a very powerful tactic/position.

Chris

Richard Jones

Chris, if you want to know why Seeman's work is quite different to mechanosynthesis, read my book again. If you now think that the approach to nanotechnology outlined in Soft Machines is the right one, that's great, come out and say so. But the last time you mentioned the book, it was to say it was wrong.

Philip Moriarty

There follows an interesting quote from Drexler on the efficacy of covalently bound systems for mechanosynthesis (taken from evidence he gave to the Royal Society committee last year).

"The goal for engineering work is to choose systems which are deliberately designed to be as stable and unambiguous in their outcomes as possible. In trying to understand future capabilities, this leads to an emphasis on strong covalently bonded solids, which locally resemble ceramics or diamonds. And looking at surfaces that, except in very local and controlled circumstances, are saturated in a covalent bonding sense, and therefore are stable in the way that diamonds and certain ceramic and semi-conductor surfaces are stable."

Chris, I thought that your current argument was that Drexler chose diamond not because it was the best system but because it was one of the more difficult systems. Moreover, in the same post on Soft Machines you raise once again the spectre of 'universal capability' ( "I said that we did not yet know the difficulty of achieving near-universal competence"). I particularly like the classification of metals as 'heavy and rare' and therefore it's not such a huge restriction if mechanosynthesis can't use them. I thought that you were particularly keen on plasmonics at the moment? (...and let's not bring up the issue of magnetism).

Drexler: "...and looking at surfaces that, except in very local and controlled circumstances, are saturated in a covalent bonding sense,". As I've said before, Drexler knew precisely what he was doing when he chose H-passivated diamond and covalently bound materials. To understand why, take the time to read those surface science text books I recommended to you in our debate. Moreover, you'll find there the answers to your recent questions on defect densities and the use of cooling to 'kinetically limit' surface reconstruction (at least I think this is to what you were alluding).

Philip

Chris Phoenix, CRN

Richard, I didn't say your book was wrong about soft machines. I said that it was wrong about less-soft machines.

Philip, quote me in context and I'll answer you.

Chris

Philip Moriarty

Chris,

"But the current broadening of scope is not obfuscation; it is simply de-strawmanning the discussion"

Ah yes, the trusty strawman argument raises its head again. See here for discussion on this topic.

As I believe the cartoon character Snagglepuss used to say, I'll exit stage left.

Best wishes,

Philip

Chris Phoenix, CRN

Yes, the idea of a singular "universal assembler" machine is indeed a strawman, unsupported by the text of the EoC section headlined "universal assemblers". The term does not appear in the text; what does appear is phrases like "some will serve as improved devices" and "depending on design."

Since I suspect you included that URL in order to claim the exact opposite, it's probably just as well we're ending the discussion here.

Chris

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