Open letter, 2 July 2003
Thanks for your prompt note promising to respond to my 16 April open letter  within a few weeks; more than two months have now passed, and it would be good to hear from you. The issues under discussion are fundamental to understanding both the feasible objectives and the natural consequences of nanotechnology research. It would be a service to the community to reach closure.
As you know, I follow Feynman  in arguing the feasibility of building with atom-by-atom control. You endorsed this goal in 1999, stating that we will "learn to build things at the ultimate level of control, one atom at a time" , then rejected it in 2001, stating that "To put every atom in its place -- the vision articulated by some nanotechnologists -- would require magic fingers" , but apparently retract this rejection in 2003, stating that "The ultimate nanotechnology builds at the ultimate level of finesse one atom at a time, and does it with molecular perfection" .
Your 2001 essay  created the impression that you had shown building with atom-by-atom control to be impossible, but my open letter  pointed out that your argument misrepresents the basic idea (shared by myself and Feynman) that the goal is to control where each atom ends up in the product structure -- as happens in chemical and biological synthesis -- not to grab and manipulate impossibly many neighboring atoms separately and simultaneously. Your recent silence and 2003 statement (above) now suggest that you have abandoned your 2001 position and rejoined Feynman in endorsing the feasibility of atom-by-atom control. Can the nanotechnology research community take this as your best judgment on the question?
I would not ordinarily raise an issue so persistently, but the question of what nanotechnology can ultimately achieve is perhaps the most fundamental issue in the field today -- it shapes basic objectives and expectations -- and your words have been remarkably effective in changing how this issue is perceived.
Yours in search of closure,
K. Eric Drexler
Chairman, Foresight Institute
1. Drexler, K. E., 2003. "Open Letter to Richard Smalley." Reprinted in
Small Times, May/June, p.10. http://www.foresight.org/nano/Letter.html
2. Feynman, R., 1959. "There's Plenty of Room at the Bottom: An invitation
to Enter a New Field of Physics," Talk at the Annual Meeting of the American
Physical Society. http://www.its.caltech.edu/~feynman/plenty.html
3. Smalley, R. E, 1999. Written statement, U.S. Senate Committee on
Commerce, Science, and Transportation, May 12. http://www.senate.gov/~commerce/hearings/hearin99.htm
4. Smalley, R. E,, 2001. "Of chemistry, love and nanobots - How soon will we
see the nanometer-scale robots envisaged by K. Eric Drexler and other
molecular nanotechologists? The simple answer is never." Scientific
American, September, 68-69. http://www.ruf.rice.edu/~smalleyg/rick%27s%20publications/SA285-76.pdf
5. Smalley, 2003. Presentation to the President's Council of Advisors on
Science and Technology, March 3. http://www.ostp.gov/PCAST/march3meetingagenda.html