Meeting notice: 12-01-17-98; 7:30 p.m. Royal East (782 Main St., Cambridge), a block down from the corner of Main St. and Mass Ave. Suggested Topic: Soft Machines George Whitesides of Harvard is well known among NT buffs for his research in such alternate microsystem fabrication models as self-assembly and/or non-covalent synthesis. Recently he gave a talk here on another example: "Soft Lithography", a term for microprinting and micromolding (including microembossing) on and with a variety of elastic polymers and other materials with special properties. The idea is to self-assemble a monomolecular polymer film, impose a pattern with any of several techniques, and then use deposits, masks and baths to form special features, including posts, wells, channels, cut-outs, and multiple layers, as desired. Feature resolution is ~50 nm. The virtues of Soft-l are that it is highly compatible with chemical and biological applications and costs are low. Many of the techniques can be executed with a high-quality (3300 dpi) printer. At one point Whitesides characterized soft-l as 'microscale technology with the economics of newsprint'. The primary applications envisaged at present seem to be microfluidics and microanalytics (Whitesides said products in these sectors were already under development), though he was confident that the opportunities for adding electrical, electronic, optical, and magnetic properties were all very inviting. He was also optimistic about using soft lithography to build MEMS and thin-film batteries, though he said almost nothing about these. I had the impression that many of these ideas could have been explored thirty years ago. The lecture posed the question of why synthetic chemistry and lithography have had so little to do with each other until now. Whatever was separating them, the wall is down now. Whitesides' lecture was basically a breakneck survey of all the good ideas revealed thereby and ready for exploration. Minutes: Last week the question was raised as to whether an acceleration in technological change is really taking place, as many assert, and if so, what effect that might have on the willingness of people and institutions to devise long-run plans. One analogy to use in probing the question is that of 'r' vs 'K' selection. These terms refer to opposed selection pressures. 'r' pertains in rapidly changing and 'K' in stable environments. 'K' behaviors include large adult size, delayed maturity, few offspring, high levels of parental investment, monogamous sexuality, and sexual monomorphism. 'r' are of course the reverse. Mice are in general an 'r' species; whales are a 'K'. This analogy hints at a quasi-objective test: if human behavior seems r-like, that suggests the predictivity of the environment is falling. The tool can also be grasped from the other end: if we think the future will become more chaotic, we might predict that human behavior should respond by being more r-like. One problem is that human behavior is not necessarily all of a piece; it might be K-like wrt reproduction and r-like wrt to finance. For instance, in the future it might be that we will hedge our portfolios in many more directions than we do now while requiring investments to perform on a weekly or even a daily basis. (Both of these are r-behaviors). The day might come when quarterly evaluations will seem intolerably risky. Announcement Archive: http://world.std.com/~fhapgood/nsgpage.html. hapgood@pobox.com