Nanotechnology: Drexler and Smalley make the case for and against 'molecular assemblers' (Richard Smalley argues that laws of chemistry imply it will be impossible to ever create "self-replicating nanobots" whose abilities to assemble molecules are significantly different than those of biological self-replicators. Some pro-nanobot responses to Smalley's argument can be found at Debate About Assemblers — Smalley Rebuttal, The Drexler-Smalley debate on molecular assembly, Of Chemistry, Nanobots, and Policy, and Is the Revolution Real?)