Microsoft Word Kurzweil, Ray The Singularity Is Near doc

The Debate Heats Up 
In April 2003 Drexler challenged Smalley's 
Scientific American
article with an open letter.
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Citing twenty years of 
research by himself and others, the letter responded specifically to Smalley's fat- and sticky-fingers objections. As I 

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discussed above, molecular assemblers were never described as having fingers at all but rather relying on precise 
positioning of reactive molecules. Drexler cited biological enzymes and ribosomes as examples of precise molecular 
assembly in the natural world. Drexler closed by quoting Smalley's own observation, "When a scientist says something 
is possible, they're probably underestimating how long it will take. But if they say it's impossible, they're probably 
wrong." 
Three more rounds of this debate occurred in 2003. Smalley responded to Drexler's open letter by backing off of 
his fat- and sticky-fingers objections and acknowledging that enzymes and ribosomes do indeed engage in the precise 
molecular assembly that Smalley had earlier indicated was impossible. Smalley then argued that biological enzymes 
work only in water and that such water-based chemistry is limited to biological structures such as "wood, flesh and 
bone." As Drexler has stated, this, too, is erroneous.
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Many enzymes, even those that ordinarily work in water, can 
also function in anhydrous organic solvents, and some enzymes can operate on substrates in the vapor phase, with no 
liquid at all.
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Smalley goes on to state (without any derivation or citations) that enzymatic-like reactions can take place only 
with biological enzymes and in chemical reactions involving water. This is also mistaken. MIT professor of chemistry 
and biological engineering Alexander Klibanov demonstrated such nonaqueous (not involving water) enzyme catalysis 
in 1984. Klibanov writes in 2003, "Clearly [Smalley's] statements about nonaqueous enzyme catalysis are incorrect. 
There have been hundreds and perhaps thousands of papers published about nonaqueous enzyme catalysis since our 
first paper was published 20 years ago."
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It's easy to see why biological evolution adopted water-based chemistry. Water is a very abundant substance on 
our planet, and constitutes 70 to 90 percent of our bodies, our food, and indeed of all organic matter. The three-
dimensional electrical properties of water are quite powerful and can break apart the strong chemical bonds of other 
compounds. Water is considered "the universal solvent," and because it is involved in most of the biochemical 
pathways in our bodies we can regard the chemistry of life on our planet primarily as water chemistry. However, the 
primary thrust of our technology has been to develop systems that are not limited to the restrictions of biological 
evolution, which exclusively adopted water-based chemistry and proteins as its foundation. Biological systems can fly, 
but if you want to fly at thirty thousand feet and at hundreds or thousands of miles per hour, you would use our 
modern technology, not proteins. Biological systems such as human brains can remember things and do calculations, 
but if you want to do data mining on billions of items of information, you would want to use electronic technology, not 
unassisted human brains. 
Smalley is ignoring the past decade of research on alternative means of positioning molecular fragments using 
precisely guided molecular reactions. Precisely controlled synthesis of diamondoid material has been extensively 
studied, including the ability to remove a single hydrogen atom from a hydrogenated diamond surface
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and the 
ability to add one or more carbon atoms to a diamond surface.
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Related research supporting the feasibility of 
hydrogen abstraction and precisely guided diamondoid synthesis has been conducted at the Materials and Process 
Simulation Center at Caltech; the department of materials science and engineering at North Carolina State University; 
the Institute for Molecular Manufacturing at the University of Kentucky; the U.S. Naval Academy; and the Xerox Palo 
Alto Research Center.
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Smalley also avoids mentioning the well-established SPM mentioned above, which uses precisely controlled 
molecular reactions. Building on these concepts, Ralph Merkle has described possible tip reactions that could involve 
up to four reactants.
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There is an extensive literature on site-specific reactions that have the potential to be precisely 
guided and thus could be feasible for the tip chemistry in a molecular assembler.
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Recently, many tools that go 
beyond SPMs are emerging that can reliably manipulate atoms and molecular fragments. 
On September 3, 2003, Drexler responded to Smalley's response to his initial letter by alluding once again to the 
extensive body of literature that Smalley fails to address.
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He cited the analogy to a modern factory, only at a 
nanoscale. He cited analyses of transition-state theory indicating that positional control would be feasible at megahertz 
frequencies for appropriately selected reactants. 

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Smalley again responded with a letter that is short on specific citations and current research and long on imprecise 
metaphors.
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He writes, for example, that "much like you can't make a boy and a girl fall in love with each other 
simply by pushing them together, you cannot make precise chemistry occur as desired between two molecular objects 
with simple mechanical motion....[It] cannot be done simply by mushing two molecular objects together." He again 
acknowledges that enzymes do in fact accomplish this but refuses to accept that such reactions could take place 
outside of a biology-like system: "This is why I led you ... to talk about real chemistry with real enzymes....[A]ny such 
system will need a liquid medium. For the enzymes we know about, that liquid will have to be water, and the types of 
things that can be synthesized with water around cannot be much broader than meat and bone of biology." 
Smalley's argument is of the form "We don't have X today, therefore X is impossible." We encounter this class of 
argument repeatedly in the area of artificial intelligence. Critics will cite the limitations of today's systems as proof that 
such limitations are inherent and can never be overcome. For example, such critics disregard the extensive list of 
contemporary examples of AI (see the section "A Narrow AI Sampler" on p. 279) that represent commercially 
available working systems that were only research programs a decade ago. 
Those of us who attempt to project into the future based on well-grounded methodologies are at a disadvantage. 
Certain future realities may be inevitable, but they are not yet manifest, so they are easy to deny. A small body of 
thought at the beginning of the twentieth century insisted that heavier-than-air flight was feasible, but mainstream 
skeptics could simply point out that if it was so feasible, why had it never been demonstrated? 
Smalley reveals at least part of his motives at the end of his most recent letter when he writes: 
A few weeks ago I gave a talk on nanotechnology and energy titled "Be a Scientist, Save the World" to about 700 
middle and high school students in the Spring Branch ISO, a large public school system here in the Houston area. 
Leading up to my visit the students were asked to write an essay on "why I am a Nanogeek". Hundreds responded, and 
I had the privilege of reading the top 30 essays, picking my favorite top 5. Of the essays I read, nearly half assumed 
that self-replicating nanobots were possible, and most were deeply worried about what would happen in their future as 
these nanobots spread around the world. I did what I could to allay their fears, but there is no question that many of 
these youngsters have been told a bedtime story that is deeply troubling. 
You and people around you have scared our children. 
I would point out to Smalley that earlier critics also expressed skepticism that either worldwide communication 
networks or software viruses that would spread across them were feasible. Today, we have both the benefits and the 
vulnerabilities from these capabilities. However, along with the danger of software viruses has emerged a 
technological immune system. We are obtaining far more gain than harm from this latest example of intertwined 
promise and peril. 
Smalley's approach to reassuring the public about the potential abuse of this future technology is not the right 
strategy. By denying the feasibility of nanotechnology-based assembly, he is also denying its potential. Denying both 
the promise and the peril of molecular assembly will ultimately backfire and will fail to guide research in the needed 
constructive direction. By the 2020s molecular assembly will provide tools to effectively combat poverty, clean up our 
environment, overcome disease, extend human longevity, and many other worthwhile pursuits. Like every other 
technology that humankind has created, it can also be used to amplify and enable our destructive side. It's important 
that we approach this technology in a knowledgeable manner to gain the profound benefits it promises, while avoiding 
its dangers.