Bill Bill Beam wrote: > On Tue, 29 May 2007 16:31:40 +1200, Dr Bruce Griffiths wrote: > > >> Ulrich, Didier >> >> Talking about forces, gravitational fields etc makes no physical sense >> if the observer's reference frame isn't specified. >> For an observer in/on a satellite orbiting about the Earth with their >> reference frame fixed with respect to the satellite. >> There is no gravitational field, whatever methods chosen to measure a >> gravitational field (within the satellite) will always produce a null >> result. >> > > Not true. > Very simple experiments will show occupants of the satellite that they > are in a non-inertial reference frame. (Release a few test masses > about the cabin and you will observe that they move/accelerate for no > apparent reason, unless the satellite is in free fall which you'll know soon > enough,) The experimenter must conclude that the satellite is undergoing > acceleration due to the influence of an attractive (gravitational) field. > > Just because NASA calls it 'microgravity' doesn't make it true. It means > NASA is wrong. Weightlessness is not the same as zero-g. > > Only, if you insist on sticking to Newtonian physics with all its attendant problems.
>> Pendulum clocks fail to work, given an initial push they will just >> rotate around the pivot, provided the pivot suitably constrains the >> motion of the pendulum (ie a shaft running in a set of ball or roller >> bearings or similar and not a knife edge pivot). >> >> If, however the satellite acts as a rigid body and has a large enough >> diameter then it would be possible for an observer on the satellite to >> detect a gravitational field gradient. >> > > Therefore, you must conclude that somewhere inside the satellite g is not > zero. > > A finite gradient doesn't imply that the field itself is nonzero, except of course towards the extremeities of the satellite. > > Regards, > Bill Beam (PhD, physics 1966, past tenured Associate Professor of Physics) > > > Bill Beam > NL7F > > > Bruce _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts