ernst%home@ti-csl.CSNET.UUCP (06/18/87)
The "nano-engineering" that David Smith heard about on an early-morning NPR show is, indeed, no joke. Its chief proponent is K. Eric Drexler, who describes the theory in his 1985 book _Engines of Creation_. He is associated with MIT, and he has a stong following there. In particular, Marvin Minsky wrote the forward to the above-mentioned book and spoke, along with Eric Drexler and others, at a recent day-long symposium on nano-technology at MIT. The idea behind nanotechnology is the creation of tiny machines which would be built up molecule by molecule by "molecular assemblers", which would function much like DNA or RNA in fishing for the right component to add to a structure. Because of their small size, their manipulators would move a million times a second, resulting in extraordinarily quick construction. Mechanical nanocomputers (that is, they would contain tiny gears made of a handful of atoms and such, on the order of Hillis's mechanical tic-tac-toe player) orders of magnitude more powerful than current machines but small enough to fit in dust-speck sized nanomachines would carry instructions and direct work. Drexler envisions the construction of assemblers within a few decades as a result of advances in bioengineering and other sciences. It is a technology he believes will powerfully leverage off itself: after the first assembler is built, uncountable trillions more will follow almost immediately, and scientific breakthroughs in many fields (all of which will be able to use nanotechnology or its products as a tool) will be made in days rather than years. Drexler's book is more about what changes will be made in society with the advent of nanomachines than their technical aspects; after all, no one is close to the advances he envisions. He discusses jet engines built in hours, self-repairing machines, AI workstations of unprecedented power, and world hypertext systems as well as more sinister possibilities like the capability to build tiny airborne surveillance devices or supergerms that could destroy life on earth in hours. Although much of the material is hard to believe, I recommed the book for an interesting mix of philosophy and forward-sighted scientific thought (or science fiction, call it what you like). -Michael Ernst MIT AI Lab Texas Instruments AI Lab mernst@oz.ai.mit.edu ernst%home%ti-csl@csnet-relay.arpa ...!eddie!mernst The opinions expressed above are not only not those of my employer, they may well not be my own.
MINSKY@OZ.AI.MIT.EDU (02/03/88)
Those reactionaries who were flaming at Drexler's ideas ought to read this week's issue of Nature. A group at IBM San Jose Almaden Research Center have used a scanning tunneling microscope to pin a single molecule of dimethyl phthalate to the surface of a graphite sheet and then to rearrange its atoms, and see the results. The exact details of the rearrangement are not yet controllable, but the aromatic subgroups are clearly visible. (Dimethyl phthalate is about the size of two benzene reings.) The operations can be done at sub-microsecond speed, using the order of .1 microsecond pulses at 3.5 volts. Progress in this direction certainly seems faster than almost everyone would have expected. I will make a prediction: In the next few years, various projects will request and obtain large budgets for the human genome sequencing" enterprise. In the meantime, someone will succeed in stretching single strands of protein, DNA, or RNA across crystalline surfaces, and sequence them, using the STM method. Eventually, it should become feasible to do such sequencing at multi-kilocycle rates, so that an entire chromosome could be logged in a few days. Using this system for constructive operations lies further in the future; however, it might sooner be feasible to introduce controlled damage to genetic elements. This would, for example, make it easy to inactivate particular gene-promoters and, thus, to remove a bad gene. Incidentally, these operations can be performed inside a drop of liquid (the STM does not need a vacuum). So it ought to be feasible to put the altered genetic material back into a cell.