Science

Brownian motion and nanotechnology

Brownian motion started when Robert Brown looked into his microscope and observed that pollen suspended in water moved around in a continuous random motion. Wanting to rule out some “vital life force,” Brown also  investigated dead things such as sand and metals but he observed the same jittery motion. The dead danced as well. Or perhaps the Epicureans anticipated the phenomenon of Brownian motion in Lucretius‘s scientific poem On the Nature of Things:

Observe what happens when sunbeams are admitted into a building and shed light on its shadowy places. You will see a multitude of tiny particles mingling in a multitude of ways… their dancing is an actual indication of underlying movements of matter that are hidden from our sight… It originates with the atoms which move of themselves.

The writer Mark Haw has been so fascinated with the phenomenon and history of Brownian motion that he decided to write a book about it called Middle World: The Restless Heart of Matter and Life. This accessible introduction covers the history of Brownian motion, the “mesoscopic” middle world between the (sub)atomic world and the world of “large” objects,  taking us from the puzzling observations of Robert Brown to its relevance for the upcoming science of nanotechnology. Commenting on the challenges that the middle world, where “objects simply cannot  stand still,” presents to Eric Drexler’s vision of  “hard” nanotechnology, the author observes:

Matter in the middle world does things differently.  You could insist on modeling your machines after the macroworld and finding chemical ways to achieve that. But why not use the fantastically rich range of things that matter does in the middle world to come up with whole new ways of solving engineering problems? Why not profit from unavoidable restlessness? We know it can be done: life has already done it.

Although published 3 years earlier than Haw’s book, Richard Jones picks up this very theme in his excellent book Soft Machines: Nanotechnology and Life. This book presents a more technical treatment of Brownian motion and other nanoscale phenomena that an advanced nanotechnology simply cannot work around.  But instead of resisting the unruly world of randomness and sticky objects, Jones proposes to embrace these phenomena as the most obvious road to build nanoscale devices. Although the author does not completely dismiss the “top-down” Drexler approach, he strongly prefers to use the bionanotechnological tools that nature has provided and to improve upon them. He also introduces an approach called “biomimetic nanotechnology” that would involve “the copying of the principles of operation of biological nanotechnology, but executing them in synthetic materials.”

Since August 2004, Richard Jones also publishes a blog that reports on the future of nanotechnology  and has featured informed critiques of the Drexlerian vision of radical nanotechnology and Singularitarianism.