Brownian ratchet (nonfiction)
In the philosophy of thermal and statistical physics, the Brownian ratchet or Feynman-Smoluchowski ratchet is a thought experiment about an apparent perpetual motion machine.
It was first analysed in 1912 by Polish physicist Marian Smoluchowski, and later popularized by American Nobel laureate physicist Richard Feynman in a physics lecture at the California Institute of Technology on May 11, 1962, during his Messenger Lectures series The Character of Physical Law in Cornell University.
The simple machine, consisting of a tiny paddle wheel and a ratchet, appears to be an example of a Maxwell's demon, able to extract useful work from random fluctuations (heat) in a system at thermal equilibrium in violation of the second law of thermodynamics.
Detailed analysis by Feynman and others showed why it cannot actually do this.
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Fiction cross-reference
Nonfiction cross-reference
- [[Maxwell's demon (nonfiction)
- Physics (nonfiction)
External links:
- Brownian ratchet @ Wikipedia
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