Eric Drexler on Alternatives to Grey Goo

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Little did I expect to be writing two articles on "grey goo" in less than a week, but Eric Drexler has just published and interesting article (with Chris Phoenix) with his updated perspective on this subject. The articles is published by the Institute of Physics, and can be downloaded free, for one month (registration required).

As I noted in a previous post, Drexler had warned in his 1990 book Engines of Creation, of a worst-case nanotechnology catastrophe in which the biosphere is destroyed by self-replicating bacteria-like nanomachines. This scenario was, and continues to be referred to as the "grey goo" scenario.

Phoenix and Drexler now worry that too much emphasis is being placed on the "grey goo" scenario, and too little on other dangers posed by nanotechnology. Each part of this is interesting.

On the positive side, they think we need not worry unduly about grey goo because current views of nanomanufacturing focus not on self-replicating assemblers, but rather on minaturized versions of conventional factories. This is extremely good news, and I think does go a long way to justifying his claim that the "grey goo" worries are not massively relevant to the kind of nanomanufacturing in which we are likely to engage. We need to be very clear, however, that what has changed here is that Drexler and others are now advocating a different, and much safer, manufacturing approach: if the self-replicating assembler route were to be pursued the danger would be present. Phoenix and Drexler do also put forward a number of arguments as to why, risks apart, assembler-based self-replication would be hard, inefficient, and difficult to make robust enough for the "grey goo" scenario to be relised. Again, these arguments seem very plausible, but do not alter the fact that any self-replicating nanotechnology would be pregnant with risks and should probably be avoided.

On the less positive side, Phoenix and Drexler emphasize that the development of nanotechnologies does pose very grave risks for humanity. Their concluding sentence is:

Problems including weapon systems, radical shifts of economic and political power, and aggregate environmental risks from novel products and large-scale production will require close attention and careful policy-making.

This is certainly a judgement I have no difficulty at all agreeing with.

Bibliography

Eric K. Drexler, Engines of Creation. Fourth Estate (London) 1990.

Chris Phoenix and Eric Drexler, Safe Exponential manufacturing. Nanotechnology 15 2004 pp. 869--872. Institute of Physics Publishing. http://stacks.iop.org/Nano/15/869