Re: Centrifugal force

[John Mallinckrodt <ajmallinckro@CSUPomona.Edu>]

On Sat, 2 May 1998, Leigh Palmer wrote:

> Donald said:
>
> > On Fri, 1 May 1998, Leigh Palmer wrote:
> >
> > > Thanks are due only to Donald Simanek; I just jazzed it up a bit.
> >
> > I really hate to say this, but so far as I can remember, I had nothing to
> > do with this thought experiment or this thread. Someone else deserves the
> > credit. When too many levels of quotes are nested, one can easily
> > attribute something to the wrong person. Anyway, I like the experiment,
> > too.
>
> My error; I hope I didn't upset the true author too much. John?
> Was it you I slighted? I'm sorry; please come back! The important
> thing is the physics, of course, but I wanted to make it clear
> that I was not the clever fellow who thought up this wrinkle.

The hovering rocket ship is an image that I hit on a few years ago, find
*very* useful, and have used a few times in talks on gravity and the
principle of equivalence. On the other hand I wasn't sure if I had
specifically mentioned it in one of the many previous phys-l go rounds on
gravitation/centrifugal force/POE/etc. Furthermore, while I confess to
taking some pride in the contrivance, I doubt that I was the first to
which it may have occurred.  At any rate it was only my reluctance to
enter the fray again coupled with the distractions surrounding the 25th
year reunion with my old Harvey Mudd College classmates and not any sense
of slight that has kept me on the sidelines this time.

As long as I'm here, however, I might as well recast my vote for the
position that one should be able to decide for one's self how "real" or
"fictitious"  one wants to consider the centrifugal force or any other
inertial force, but I'll take exception with anyone who, having made that
decision, wants to consider the gravitational force somehow to be *any*
less or more "real." 

John
-----------------------------------------------------------------
 A. John Mallinckrodt      http://www.intranet.csupomona.edu/~ajm
 Professor of Physics    mailto:ajmallinckro@csupomona.edu
 Physics Department       voice:909-869-4054
 Cal Poly Pomona            fax:909-869-5090
 Pomona, CA 91768-4031   office:Building 8, Room 223