February 16, 2010

Ralph Merkle Molecular Manufacturing Interview by Sander Olson

Ralph Merkle Interview

Here is Sander Olson's Ralph Merkle interview. Dr. Merkle is one of the foremost molecular manufacturing experts on the planet, but his research is currently severely resource constrained. Hopefully this interview will serve to inform people about his research.

Question 1: You've just returned from the 2010 Foresight conference. How did that go?

Answer 1: It went well - I particularly enjoyed the discussion by Robin Hanson and David Friedman on the economics of future technology. The Foresight Institute is one of the few organizations which extensively examines the subject of molecular manufacturing, so I make it a point to attend their conferences.

Question 2: Recent articles in the Wall Street Journal and IEEE have supported research into molecular manufacturing. Is mainstream opinion regarding the feasibility of molecular manufacturing changing?

Answer 2: Yes, public perception is slowly changing. In particular, the Singularity University has had a noticeable impact in terms of public acceptance and in terms of the excitement that it is raising. There are increasing numbers of blogs and conferences dedicated to molecular manufacturing, and more and more scientists are willing to accept the concept that molecular manufacturing should be feasible.

Question 3: The first Foresight conference occurred in 1989. Have developments during the last twenty years matched your initial expectations?

Answer 3: I always want more and I always want it faster. We knew in 1989 that developing molecular manufacturing - which at the time we simply called "nanotechnology" – would take a while. I knew about Moore's Law in 1989 but hadn’t yet heard of Ray Kurzweil and didn’t know that exponential curves were good fits to all the information technologies. During the past decade we have seen wider recognition that if you plot technology trends on semilog paper it often provides a surprisingly accurate forecast of future capabilities. Moore's law is still going strong, and we are seeing an entire range of technologies where exponential progress is happening with remarkable regularity.

Question 4: Although you and Robert Freitas have done numerous computer simulations of molecular components and systems, there is currently a paucity of actual experimental data supporting molecular manufacturing. To what extent is this dearth of experimental data hampering development?

Answer 4: It would help if there were more experimental work, but we are seeing some experimental investigations into the feasibility of mechanosynthesis, and we are also seeing a huge body of work involving scanning probe microscopy and DNA based nanotechnology. While the stated purpose of this research may not be the development of molecular manufacturing, much of this work lays a foundation which can be used for later developments.

Question 5: The core of a nanofactory would need to operate in an absolute vacuum. Will maintaining such a vacuum be difficult?

Answer 5: An absolute vacuum isn't necessarily a prerequisite for a molecular manufacturing system – you could use an inert gas like neon which would not react with even highly reactive tools. And if you used reactions compatible with water you could do mechanosynthesis in water – though that’s not usually what people think of when they use the word “mechanosynthesis.” But if you want to synthesize diamond it is most convenient to use UHV [Ultra High Vacuum]. Excellent quality vacuums are experimentally accessible today and even rather common. Highly reactive tools (radicals and the like) that are useful in the synthesis of diamond should have usefully long half lives in systems that can be built today -- and better systems will be achievable in the future.

Question 6: How will a nanofactory deal with errors, such as those caused by radiation?

Answer 6: One of the main largely unavoidable causes of errors is radiation damage. Systems that are small enough – perhaps ten billion atoms – can avoid radiation damage entirely for decades. As systems get larger the probability of a radiation hit increases until eventually errors become inevitable. So a desktop sized nanofactory would need to have methods to deal with such errors. The simplest approach is to have multiple redundant subsystems – if you have multiple sorting rotors and one fails, the other rotors could take up the load and the system would keep working. There are a number of methods that can be used to create reliable systems despite unreliable components, so controlling errors is not an intractable problem.

Question 7: How many more years before actual diamond mechanosynthesis is shown?

Answer 7: There are efforts today to arrange small numbers of carbon atoms on a surface, and those might prove to be successful in the next few years. To arrange millions of atoms into a complex molecular structure using positional assembly and mechanosynthesis will take considerably longer. The best estimates for how long that might take could probably be gleaned from Kurzweil's extrapolations of trend data.

Question 8: In order to reproduce a copy of itself in 24 hours, an assembler will need to move a molecule at a rate of about 1 per millisecond. Are such speeds realistic at room temperature?

Answer 8: Eric Drexler's Nanosystems shows that adding a molecular component to a molecular workpiece once every microsecond with a robotic arm is clearly feasible – and this holds true both at low temperatures and room temperature. Early systems are likely to be slower, but microsecond assembly speeds should be readily attainable and systems might eventually be faster than that. We currently lack a set of mechanosynthetic reactions that we can carry out with sufficient reliability, so that is a focus of research.

Question 9: Eric Drexler argues that the best way to molecular manufacturing is by first developing DNA origami approaches. What is your response to Dr. Drexler's arguments?

Answer 9: The DNA origami approach is an interesting and important area of exploration. There are several paths towards molecular manufacturing and at this point it isn't clear which approach is best, or even if there is a “best” approach. Is it better to drive, walk, or take the bus? As long as you get where you want to go, it might not make that much difference. Robert Freitas and I have chosen to pursue the direct-to-diamondoid approach, but I support investigating all possible approaches.

Question 10: A direct-to-diamondoid approach will probably take at least 20 years, and might result in useful intermediate byproducts. Yet advanced DNA origami approaches could be developed within the next decade. Isn't the diamond mechanosynthesis approach riskier?

Answer 10: DNA origami can currently make larger atomically precise products than mechanosynthesis, but it’s less clear how to make complex diamond structures using that approach. Diamond mechanosynthesis has made less progress to date, but once we achieve basic mechanosynthetic capabilities it is clearer how to use those capabilities to make complex diamondoid parts. Which is better? Maybe both, depending on your objectives and time frame.

Question 11: Molecular manufacturing research is severely hampered by a lack of funding. Are there any private or corporate organizations that are amenable to funding your research?

Answer 11: Robert Freitas and I are pursuing this research, but we are currently resource constrained. This area is grossly underfunded so I would encourage anyone who wants this technology to happen to contact us. More funding would obviously speed development.

Question 12: Some nanotechnology researchers predict that molecular manufacturing will be first developed in China. Do you agree?

Answer 12: Given the current modest levels of funding, almost any country could develop a major effort that would dwarf all other efforts if it made molecular manufacturing development a priority. Even a large corporation could shift the balance and have a major impact, if they were able to maintain focus.

Question 13: What single development will go furthest to changing the outlook of the mainstream scientific community towards molecular manufacturing?

Answer 13: Building a complex artifact like a nanofactory will require a coordinated effort by a team of people. We’ve seen this happen before, for example when Kennedy announced we would put a man on the moon, or when the Manhattan Project mobilized resources to build an atomic bomb. There are two key requirements: (1) focus and (2) resources. If we are to build a nanofactory, someone has to provide both. Either one alone will fail.

Question 14: At current rates of progress, how confident are you that full-fledged nanofactories could arrive by 2030?

Answer 14: That depends on what we do.

Molecular manufacturing will inevitably be developed, and a few decades is a plausible timeframe. Given current rates of progress, it appears probable that by 2030 some very impressive technological capabilities will emerge. But there are major variables that are difficult to predict. The concept of a computer was actually developed by Charles Babbage in the mid 19th century, and a relay-based computer could have been built in the 1850s for a relatively modest cost. But due to the lack of a focused research effort and funding, the first relay-base computers weren't developed until the 1930s. Without a well funded and focused effort the development of molecular manufacturing could similarly be delayed by decades.

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