From: scerir (scerir@libero.it)
Date: Fri Feb 28 2003 - 12:55:33 MST
>> ... possibility of having a "motion" without propulsion
>> (i.e. not using Newton's Third Law).
Adrian Tymes:
> It's called "friction".
:-)
That Jack Wisdom is Breene M. Kerr Professor of Planetary Science
in the Department of Earth, Atmospheric, and Planetary Sciences,
Massachusetts Institute of Technology.
http://www-eaps.mit.edu/faculty/wisdom.htm
And got the 2001 Brouwer Award (given by the American Astronomical
Society) for his fundamental contributions and leadership in the
application of modern nonlinear dynamics and the theory of Hamiltonian
chaos.
Ok, once upon a time there was also prof. Eric Laithwaite, spinning
heavy wheels above his head (I saw him in London)
http://www.alternativescience.com/eric-laithwaite.htm
http://www.bbc.co.uk/history/historic_figures/laithwaite_eric.shtml
http://www.ee.ic.ac.uk/news/obituary.html
http://www.gyro-scope.co.uk/masstran.htm
http://www.padrak.com/ine/NEN_5_9_5.html
I must ask my son, who is a good ice skater, about friction,
and strange motions, as soon as possible :-)
> I'll believe it when they build a device that can
> provably do this. Not until then.
Yes, according to Frank Wilczek, also of MIT, all that presents many
interesting questions on the basic idea of what "motion" is,
especially when there are no stars or galaxies (i.e. spacetime
doesn't curve). Actually he doubts that there will be any practical
applications to this since the effect is extremely small.
"A meter-sized object gyrating in a spacetime curved as dramatically
as the surface of Earth--far more sharply than most regions of spacetime--
could make headway of only about 10-23 meters per contortion. At one
stroke per second, it would take the swimmer hundreds of thousands of
years to move the width of an atom."
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