Epicycles are only a rough approximation that doesn’t work very well, and it doesn’t in any way give you Kepler’s third law (that there’s a relationship between the orbits). I’m also confused in that even if that were the case it wouldn’t make or Kepler or Newton’s mechanics worthless. What point are you trying to make?
Obviously Kepler’s astronomical model is superior and that line might have been rhetorical flourish but the Ptolemaic, Copernican and Tychonic models were by no means “rough approximations” that don’t “work very well”. Epicycles worked very well which is part of why it took so long to get rid of them- the deviations of theory from actual planetary paths were so small that they were only detectable over long periods of time or unprecedented observational accuracy (before Brahe).
(I don’t understand the grandparent’s point either and agree that mathematical reduction to set theory is a different sort of thing from physical reduction to quantum field theory—just pointing this one thing out.)
Well, we can disassemble every planet orbit to epicycles. Does that mean that our astronomical knowledge based on Newton’s mechanics is worthless?
Epicycles are only a rough approximation that doesn’t work very well, and it doesn’t in any way give you Kepler’s third law (that there’s a relationship between the orbits). I’m also confused in that even if that were the case it wouldn’t make or Kepler or Newton’s mechanics worthless. What point are you trying to make?
Obviously Kepler’s astronomical model is superior and that line might have been rhetorical flourish but the Ptolemaic, Copernican and Tychonic models were by no means “rough approximations” that don’t “work very well”. Epicycles worked very well which is part of why it took so long to get rid of them- the deviations of theory from actual planetary paths were so small that they were only detectable over long periods of time or unprecedented observational accuracy (before Brahe).
(I don’t understand the grandparent’s point either and agree that mathematical reduction to set theory is a different sort of thing from physical reduction to quantum field theory—just pointing this one thing out.)
Yes, by doesn’t work very well, I mean more “doesn’t work very well when you have really good data.” I should have been more clear.
Epicycles can give you arbitrary precision if you use enough of them… It is quite similar to Fourier transform.
My point is that in most cases you can disassemble a 767 into various colections of parts.