No, she doesn't. Please do not tell her; she would only worry. One thing we
learn in physics is that time is relative. I don't think Stephen Jones would
think that that time is so late. My guess is that this time corresponds to
around 3:19 PM in Perth.
>Thanks for these additions. An interesting aspect of all this for
>me is that I've used these two approaches to solving mechanics
>problems all my life without ever really thinking about them.
>I use a particular method for a particular problem based on utility.
Spoken like a true engineer.
>Unfortunately, quantum mechanics is one of those things I know very little
>about. I just finished reading an excellent biography of Feynman (_Genius_,
>by Gleick) in which the above was discussed, in a more watered down way
>of course. Your description above helped me understand a little better what
>was going on.
You're welcome. I'm glad it did somebody some good.
>...
>Apparently this had an impact on Feynman since he refused to solve any
>problem by the principle of least action as an undergrad at MIT. Too
>mysterious. Reading between the lines, perhaps these experiences
>motivated Feynman's thesis work that you discuss above.
Could be. I wouldn't be surprised if you're right about this inference.
>Be that as it may (and speaking as a layman) I was somewhat surprised to
>hear your assessment "Feynman did for teleology in mechanics what Darwin
>did for teleology in biology" even though the author of the biography
>mentioned above said something very similar. It seems to me that Feynman
>has merely replaced one mystery by another mystery that is perhaps even
>greater. To be sure, Feynman provided an explanation for the principle
>of least action. But this explanation does not seem to me in any way
>similar to Darwin's explanation of biological design.
I may have overblown my rhetoric here, but what I meant was that according
to Hamilton's Principle (HP), i.e. the principle of least action, a physical
system seems to have a single-minded "purpose" to search out, find and
follow the path (in phase space) that minimizes the action between its
initial and final states. It's as if supposedly inanimate objects were
endowed with (designed to have) this mysterious ability to figure out ahead
of time the optimal trajectory (over the set of all conceivable ones) and
then to actually follow that path. It's as if the very fabric of the
universe is designed in such a way that this is the "best of all possible
worlds". Such optimality of dynamical design could be used to argue for an
intelligent Designer. My point was that Feynman's work takes away the
mystery and shows the optimality to be automatically a natural consequence of
a mindless quantum dynamics which treats all possible paths equally without
an overt appeal to such a necessary Designer. In the biological analog the
Darwinian mechanism provides a natural(istic) explanation for the biological
designs, their adaptations, quasi-optimalities, and their occasional
suboptimalities, again without explicit reference to an underlying
intelligent Designer. In both cases the existence of such a Designer may be
suggested to the theist by the data, but the atheist doesn't feel (and
doesn't need to feel) the force of the suggestion.
>Let's turn to a more general point. One of the points of my devil's
>advocate position was that the teleological approach was successful
>where we are regarding success in a rather pragmatic way. The proof
>is in the pudding, and the pudding turned out to be very tasty even
>though some may not like the oven it was cooked in. In other words,
>even if we conclude that mechanics is not teleological we still must
>admit that the teleological approach reaped a great benefit to
>science. How long would it have taken to discover the principle
>of least action without the teleological approach?
I don't know. I'm stumped. How long do you think it would have taken?
David Bowman
dbowman@gtc.georgetown.ky.us