Brownian Ratchet (exercise framed by Feynman's Lectures, l. 46)

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The discussion centers on the Brownian ratchet, a device analyzed by Feynman, which consists of a paddle and a ratchet that can rotate due to thermal motion. When temperatures are equal, the system exhibits no net rotation, as the pawl experiences random Brownian motion, occasionally failing to catch the ratchet teeth. In scenarios where one side is at a higher temperature, the average angular velocity and energy transfer can be calculated using the ideal gas law and Stokes' law for viscous drag. Participants express confusion over the role of viscosity and how to frame the problem in relation to Feynman's analysis. The conversation emphasizes the need for a deeper understanding of thermodynamic principles to solve the problem effectively.
  • #31
I now have another new favorite Feynman chapter.......he does his version of the fluctuation-dissipation theorem in 46-2 of this lecture. I think it probably not too different from the original sources Einstein-Smoluchowslki.
 
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  • #32
Hak said:
Ok, thanks, I'll try the simpler case first. I will submit my result shortly.
I'm looking forward to it.
 
  • #33
bob012345 said:
I'm looking forward to it.
I am working on it, between tomorrow and the day after tomorrow I will publish my process. Thanks.
 
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