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Thursday, August 22, 2013

Reading List: Radical Abundance

Drexler, K. Eric. Radical Abundance. New York: PublicAffairs, 2013. ISBN 978-1-61039-113-9.
Nanotechnology burst into public awareness with the publication of the author's Engines of Creation in 1986. (The author coined the word “nanotechnology” to denote engineering at the atomic scale, fabricating structures with the atomic precision of molecules. A 1974 Japanese paper had used the term “nano-technology”, but with an entirely different meaning.) Before long, the popular media were full of speculation about nanobots in the bloodstream, self-replicating assemblers terraforming planets or mining the asteroids, and a world economy transformed into one in which scarcity, in the sense we know it today, would be transcended. Those inclined to darker speculation warned of “grey goo”—runaway self-replicators which could devour the biosphere in 24 hours, or nanoengineered super weapons.

Those steeped in conventional wisdom scoffed at these “futuristic” notions, likening them to earlier predictions of nuclear power “too cheap to meter” or space colonies, but detractors found it difficult to refute Drexler's arguments that the systems he proposed violated no law of physics and that the chemistry of such structures was well-understood and predicted that, if we figured out how to construct them, they would work. Drexler's argument was reinforced when, in 1992, he published Nanosystems, a detailed technical examination of molecular engineering based upon his MIT Ph.D. dissertation.

As the 1990s progressed, there was an increasing consensus that if nanosystems existed, we would be able to fabricate nanosystems that worked as Drexler envisions, but the path from our present-day crude fabrication technologies to atomic precision on the macroscopic scale was unclear. On the other hand, there were a number of potential pathways which might get there, increasing the probability that one or more might work. The situation is not unlike that in the early days of integrated circuits. It was clear from the laws of physics that were it possible to fabricate a billion transistors on a chip they would work, but it was equally clear that a series of increasingly difficult and expensive to surmount hurdles would have to be cleared in order to fabricate such a structure. Its feasibility then became a question of whether engineers were clever enough to solve all the problems along the way and if the market for each generation of increasingly complex chips would be large enough to fund the development of the next.

A number of groups around the world, both academic and commercial, began to pursue potential paths toward nanotechnology, laying the foundation for the next step beyond conventional macromolecular chemical synthesis. It seemed like the major impediment to a rapid take-off of nanotechnology akin to that experienced in the semiconductor field was a lack of funding. But, as Eric Drexler remarked to me in a conversation in the 1990s, most of the foundation of nanotechnology was chemistry and “You can buy a lot of chemistry for a billion dollars.”

That billion dollars appeared to be at hand in 2000, when the U.S. created a billion dollar National Nanotechnology Initiative (NNI). The NNI quickly published an implementation plan which clearly stated that “the essence of nanotechnology is the ability to work at the molecular level, atom by atom, to create large structures with fundamentally new molecular organization”. And then it all went south. As is almost inevitable with government-funded science and technology programs, the usual grantmasters waddled up to the trough, stuck their snouts into the new flow of funds, and diverted it toward their research interests which have nothing to do with the mission statement of the NNI. They even managed to redefine “nanotechnology” for their own purposes to exclude the construction of objects with atomic precision. This is not to say that some of the research NNI funds isn't worthwhile, but it's not nanotechnology in the original sense of the word, and doesn't advance toward the goal of molecular manufacturing. (We often hear about government-funded research and development “picking winners and losers”. In fact, such programs pick only losers, since the winners will already have been funded by the productive sector of the economy based upon their potential return.)

In this book Drexler attempts a fundamental reset of the vision he initially presented in Engines of Creation. He concedes the word “nanotechnology” to the hogs at the federal trough and uses “atomically precise manufacturing” (APM) to denote a fabrication technology which, starting from simple molecular feedstocks, can make anything by fabricating and assembling parts in a hierarchical fashion. Just as books, music, and movies have become data files which can be transferred around the globe in seconds, copied at no cost, and accessed by a generic portable device, physical objects will be encoded as fabrication instructions which a generic factory can create as required, constrained only that the size of the factory be large enough to assemble the final product. But the same garage-sized factory can crank out automobiles, motorboats, small aircraft, bicycles, computers, furniture, and anything on that scale or smaller just as your laser printer can print any document whatsoever as long as you have a page description of it.

Further, many of these objects can be manufactured using almost exclusively the most abundant elements on Earth, reducing cost and eliminating resource constraints. And atomic precision means that there will be no waste products from the manufacturing process—all intermediate products not present in the final product will be turned back into feedstock. Ponder, for a few moments, the consequences of this for the global economy.

In chapter 5 the author introduces a heuristic for visualising the nanoscale. Imagine the world scaled up in size by a factor of ten million, and time slowed down by the same factor. This scaling preserves properties such as velocity, force, and mass, and allows visualising nanoscale machines as the same size and operating speed as those with which we are familiar. At this scale a single transistor on a contemporary microchip would be about as big as an iPad and the entire chip the size of Belgium. Using this viewpoint, the author acquaints the reader with the realities of the nanoscale and demonstrates that analogues of macroscopic machines, when we figure out how to fabricate them, will work and, because they will operate ten million times faster, will be able to process macroscopic quantities of material on a practical time scale.

But can we build them? Here, Drexler introduces the concept of “exploratory engineering”: using the known laws of physics and conservative principles of engineering to explore what is possible. Essentially, there is a landscape of feasibility. One portion is what we have already accomplished, another which is ruled out by the laws of physics. The rest is that which we could accomplish if we could figure out how and could afford it. This is a huge domain—given unlimited funds and a few decades to work on the problem, there is little doubt one could build a particle accelerator which circled the Earth's equator. Drexler cites the work of Konstantin Tsiolkovsky as a masterpiece of exploratory engineering highly relevant to atomically precise manufacturing. By 1903, working alone, he had demonstrated the feasibility of achieving Earth orbit by means of a multistage rocket burning liquid hydrogen and oxygen. Now, Tsiolkovsky had no idea how to build the necessary engines, fuel tanks, guidance systems, launch facilities, etc., but from basic principles he was able to show that no physical law ruled out their construction and that known materials would suffice for them to work. We are in much the same position with APM today.

The tone of this book is rather curious. Perhaps having been burned by his earlier work being sensationalised, the author is reserved to such an extent that on p. 275 he includes a two pargraph aside urging readers to “curb their enthusiasm”, and much of the text, while discussing what may be the most significant development in human history since the invention of agriculture, often reads like a white paper from the Brookings Institution with half a dozen authors: “Profound changes in national interests will call for a ground-up review of grand strategy. Means and ends, risks and opportunities, the future self-perceived interests of today's strategic competitors—none of these can be taken for granted.” (p. 269)

I am also dismayed to see that Drexler appears to have bought in to the whole anthropogenic global warming scam and repeatedly genuflects to the whole “carbon is bad” nonsense. The acknowledgements include a former advisor to the anti-human World Wide Fund for Nature.

Despite quibbles, if you've been thinking “Hey, it's the 21st century, where's my nanotechnology?”, this is the book to read. It chronicles steady progress on the foundations of APM and multiple paths through which the intermediate steps toward achieving it may be achieved. It is enlightening and encouraging. Just don't get enthusiastic.

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