Re: [Phys-L] [SPAM] Re: Physics, Errors and Different Teaching Styles

[Hugh Haskell <haskellh@verizon.net>]

At 8:33 AM -0700 6/27/12, Bernard Cleyet wrote:
> On 2012, Jun 27, , at 07:50, John Clement wrote:
>
> >  One of the challenging, but good activities is to ask how high does
> >  something float in water on the Moon compared to the Earth.  Actually having
> >  students translate situations to the moon is very helpful in getting them to
> >  straighten out some thinking.
>
> I think using extremes are a method to clarify thinking.. How about 
> how high it floats in no g field, e.g. on the space station.
Right. And that just complicates things further, because g is *not* 
zero at the space station. It's at least 8-9 N/kg. You want to 
consider it somewhere where g is close to zero--perhaps in deep 
space, where g might approach zero (but we all no that there is 
nowhere where Newtonian gravity is exactly zero. If there were there 
would be no galaxies or clusters of galaxies, or even superclusters 
of galaxies).

Exercise for the reader: is the effect of rotation on buoyancy of an 
orbiting object noticeable, or have I raised a practical tempest in a 
teapot--even though I think it is a pedagogically important point?

Hugh
--
Hugh Haskell
mailto:hugh@ieer.org
mailto:haskellh@verizon.net

I have been wondering for a long time why some of our own defense 
officials do not
put more emphasis on finding a good substitute for oil and worry less 
about where
more oil is to come from.  Our people are ingenious. New discoveries 
are all around
us, and when we have to make them, we nearly always do.

						Eleanor Roosevelt
						February 13, 1948