Stephen A. Lawrence wrote: > > > Charles M. Brown wrote: >> Feynman's ratchet used one sprung pawl on a ratchet wheel. The spring >> biases the pawl towards the ratchet wheel so mechanical pressure on >> the gentle slope of the ratchet wheel drives the wheel the wrong way >> where it can rest against the sharp or even overhanging slope. If the >> pawl is then lifted by Brownian motion and the ratchet wheel moves a >> little the wrong way when the pawl is high, possible 50% of the time, >> than the wheel will rotate the wrong way. If the ratchet wheel moves a >> little the right way when the pawl is high, possible 50% of the time, >> then the pawl will return to a low part of the gentle slope near the >> sharp slope. >> If there are many pawls on one ratchet wheel than they do not have to >> be biased by springs because the probability is high, and increases >> exponentially with the number of pawls, that at least one pawl of a >> similar position group will be in position to block counter rotation >> of the ratchet wheel. This type of system should behave like a larger >> scale mechanically rectified ratchet wheel at thermal power levels. >> >> I don't think Feynman tried hard enough to break the Second Law. >> Fabricating a device that fails with inadequate design doesn't prove >> that a better design won't work. > > Indeed, you can't prove a theorem with examples, no matter how many > examples you have; using an example can only serve to disprove it (if > the example happens to violate it). > > One of my big flops in school was thermo -- I dropped the course at the > point where the textbook presented a "proof" of something or other which > I simply could not follow. As far as I could see the proof didn't prove > anything -- and when I asked about it during the next lecture, well, > that's when I found out the professor was /deaf/. There I was, sitting > in the hall, in a front row seat, with the prof struggling to hear my > question -- he walked over to stand right in front of my chair with his > hand cupped around his ear and had me repeat it, really loud, for about > the fourth time -- with 200 other students sitting in stunned silence in > back of me. Finally the prof went back up to the board and answered the > wrong question 'cause he never had managed to hear what I was asking. > > And so I filled out a drop slip and sold the textbook and never did > really learn the subject, beyond Feynman's brief treatment in his > physics lectures. > > >> Classical treatment of Feynman's ratchet: >> >> http://www.eleceng.adelaide.edu.au/Groups/parrondo/ratchet.html >> >> Aloha, >> >> Charlie >> > >
Was the teacher just playing with you so he did not have to answer your question regarding proof?
Regards, Paul Lowrance
