Support for Nanobots Shrinking
http://www.wired.com/news/technology/0,1282,59268,00.html
"(Nanorobotics) isn't a serious issue on the science side. It's really science fiction," Stephen Quake, a California Institute of Technology physicist, said.
Critics contend that the constant motion of atoms and molecules makes molecular machines nearly impossible to construct. Heisenberg's uncertainty principle -- the theory that the more you know about a subatomic particle's position, the less you know about its momentum, and vice versa -- also argues against nanobots. How can you manipulate atoms if their component pieces are so hard to find?