Richard Feynman's famous talk on atom-by-atom assembly is often credited with kick-starting nanotechnology...Fifty years ago, the near-legendary physicist Richard Feynman of the California Institute of Technology (Caltech) gave a talk called There's plenty of room at the bottom to the American Physical Society's West Coast section. He outlined a vision of what would later be called nanotechnology, imagining 'that we could arrange atoms one by one, just as we want them'. The rest is history.
But what sort of history? Did Feynman's talk, published the following year in Caltech's house magazine Engineering and science, really kick-start nanotechnology, or is that just a convenient fiction to link this emerging field to a colourful visionary?...
...Feynman's talk didn't in any sense start nanotechnology. It didn't really stimulate any new research at all, although the miniaturisation challenges he set sparked some neat feats of engineering. Indeed, some of Feynman's contemporaries even wondered if his intent was purely comic (which would have been very much in character). Very little of the later, foundational work in nanotech drew on Feynman's vision, and most was conducted in complete ignorance of it...
...While it might be wise to stop pretending that his address to the APS was the 'birth of nanotechnology,' that needn't prevent us from relishing the spectacle of a genius giving free rein to his imagination. It was, according to George Whitesides of Harvard University, US, 'yet more validation, if any were needed, of Feynman's perceptiveness and openness to new ideas'...
...one of the most significant aspects of Feynman's text is its focus on information. It was already becoming clear in 1959, a year after the invention of the integrated circuit, that miniaturisation would be important in computer technology. 'Work on the transistor had been miniaturising and miniaturising since its invention in 1947,' says chemist Mark Ratner, also at Northwestern and author of Nanotechnology . 'Whether the physics community thought in those terms isn't so clear, but Feynman was certainly aware of what the engineers' thoughts were.' All the same, this was six years before Gordon Moore of Intel coined his renowned 'law' describing the shrinking of computer circuit elements, and there was none of the now commonplace presumption that data storage and processing would have to happen at an ever-decreasing scale. Yet Feynman proclaimed that, with a capacity for atom-craft, 'all of the information that man has carefully accumulated in all the books in the world can be written . in a cube of material one two-hundredth of an inch wide.'
What's more, he recognised how much of this facility for manipulating matter and storing information at the nanoscale was already apparent in biological systems. In DNA, he said, 'approximately 50 atoms are used for one bit of information about the cell'. And biology 'is not simply writing information; it is doing something about it'. Today, molecular and cell biology are frequently cited not only as an 'existence proof' that nanotechnology is possible but as a rich store of ideas for how it might be achieved. But in 1959, says Dekker, 'people simply were not thinking about biological structures in terms of machines'. That Feynman did so only six years after the discovery of the information-encoding structure of DNA was remarkable. 'If I look at the two biggest technological revolutions in the past half century, I would mention information technology and the molecular biology revolution,' says Dekker. 'Feynman mentioned both.'...
...Where Feynman scores less strongly is on the role of chemistry in nanoscale engineering. 'He spent a lot of time thinking about computation and computers, but not much time thinking about molecules and the way they organise space and matter,' says Ratner. 'My guess is that if you presented him with a five-coordinate carbon atom, it wouldn't have bothered him any more than a four-coordinate carbon atom would have. The soft-matter world was not his forte.'
Most crucially, he seems not to have appreciated (in fairness, neither did anyone else at the time) that nature's prowess in nanotechnology relies heavily on the propensity of chemical systems to self-assemble...
Where Feynman scores less strongly is on the role of chemistry in nanoscale engineering. 'He spent a lot of time thinking about computation and computers, but not much time thinking about molecules and the way they organise space and matter,' says Ratner. 'My guess is that if you presented him with a five-coordinate carbon atom, it wouldn't have bothered him any more than a four-coordinate carbon atom would have. The soft-matter world was not his forte.'...
...For all its strengths and weaknesses, did anyone actually listen to Feynman's ideas? 'Feynman was Feynman,' says Ratner, 'and a lot of people would listen to him who might not be willing to listen to people of lesser reputation, in part because he put things so beautifully.' Yet if they listened, it's not clear that they were inspired to act. In a myth-busting article of 2005 published, cheekily, also in Engineering and science , anthropologist Chris Toumey of the University of South Carolina dissected the real 'influence' of Feynman's talk. How many citations did Plenty of room generate, Toumey asked? Until 1980, you could count them on your fingers: three in the 1960s, four in the 1970s. And one of these, a survey of advances in information technology in 1969, called Feynman's speculations about storing information in single atoms 'completely vacuous as far as the real world is concerned'.
Even if that last remark chalks up a point for Feynman, the evidence therefore suggests that his ideas were at first almost totally ignored. Then, from around 1980 until 2002, the growth in citations increased exponentially. What made the difference?
Two things, Toumey suspects. One was that the science caught up. The STM and its ilk were invented during the early 1980s by Gerd Binnig of IBM's research laboratories in Zürich and his collaborators, Heinrich Rohrer and Christoph Gerber at IBM and Calvin Quate at Stanford University in California. Eigler says that 'Feynman's work would be on a dusty shelf without Binnig. It was Binnig who blew life into nano by creating the machine that fired our imaginations'.
Yet the inventors of these devices didn't even know what Feynman had said. 'Binnig and I neither heard of Feynman's paper until scanning tunnelling microscopy was widely accepted in the scientific community . nor did any of our papers ever refer to it,' says Rohrer. Quate denies prior knowledge of it, and Binnig told Toumey that even then he hadn't read it.
The other reason for the rising fame of Feynman's talk was more controversial. In 1981 engineer K Eric Drexler published a paper entitled Molecular engineering: an approach to the development of general capabilities for molecular manipulation . It cited Feynman in the very first sentence, and went on to outline a vision of 'microtechnology' at the molecular scale that Drexler later developed in his 1986 book Engines of creation , which became the point of entry to nanotechnology for many lay readers...
...Drexler's blueprint for nanotechnology has been criticised extensively, most famously by an acerbic exchange with the late Richard Smalley of Rice University, a discoverer of nano's poster molecule C60. Much of this criticism centres on Drexler's mechanistic literalism and its apparent neglect of chemical principles, which restrict what is possible by mechanical means but also offer smarter ways of achieving similar goals. That, however, isn't the point here. Even Drexler's critics cannot deny that he was hugely influential to the public visibility of nanotechnology in its early days, boosted by Drexler's founding of the Foresight Institute in Palo Alto, California, to promote the topic generally and Drexler's 'molecular machinery' version of it in particular. And at every juncture, Drexler took the opportunity to promote Feynman's talk as the foundational text of the subject, perhaps because it meshed so well with his own vision.
This may lead some chemists to be sceptical of Feynman's insights. Jim Gimzewski, a specialist in STM nano-manipulation at the University of California at Los Angeles, US, dismisses many of them as 'the basis of Drexler's mechanistic Newtonian models' of nanotech. 'Neither Feynman nor Drexler appreciated the ability of chemical synthesis to respond to the nanotechnological age,' says Fraser Stoddart. 'Both saw it as a given in the same billiard-ball type mode that had met the needs of the dye-stuffs and pharmaceutical industries.'...
...Whether or not the true founders of the science of nanotechnology knew of Feynman's talk at the time, no one who enters this field can be ignorant of it now. What do they make of it? Is it a source of inspiration, a curiosity, or an irrelevance? 'I had read it a long time before first manipulating atoms with the STM,' says Eigler. 'Within weeks of [doing that work], I went back to dig up Feynman's paper. I was more than ever impressed with how prescient Feynman's thought were.'
'I am not so inspired by the talk's content,' says Gimzewski, 'but more by the fact that he did speculate and was not the typical academic. He had character and was a bit crazy.' Whether any of these speculations hit the mark is not really the point, he says. 'He threw a bunch of darts, and some accidentally landed on where the future was going. He carpet-bombed the future.'
Whitesides believes that, for most researchers, an interest in what Feynman says comes post hoc : 'My sense is that most people in nano become excited about it for their own reasons, and then lean on Feynman as part of their justification for their interest. Most scientists require "permission" to work in new areas, and Feynman provided that.' For his own part, Whitesides says that Feynman's talk 'had no influence on what we have done. 'Late on, I have read parts of it, but only parts. It has never seemed that relevant'.
'Feynman had a dream, but he did not come up with a blueprint,' says Stoddart. 'Yet it would have been asking a lot of him to see much beyond what he did see and predict. He did not recognise the power of chemistry to drive nanotechnology in a meaningful way. He did, however, help to stimulate a number of chemists to start thinking about meaningful ways to do bottom-up manufacturing.'
Perhaps in the end the inspiration Feynman offers comes not from what he said, but from the fact that he said it at all. 'In a world in which atoms and molecules and small structures were "not physics" and not fashionable,' says Whitesides, 'Feynman said "Oh yes they are and there is lots to do there!'" That took great imagination, says Ratner. 'Bold speculative visions are wonderful, and imagination is crucial to the development and introduction of new scientific ideas. And imagination was Feynman's great stock in trade.'
