" actually earth's gravitational field is stronger at sea level than it is say at the top of Mt
Everest. so weight does vary according to distance from the center of gravity of a massive
object. "

That's not the point. The point is, any object not in direct contact with the earth's surface, even just an inch, has no weight. That is true at the top of Mt. Everest or near the Dead Sea - altitude has nothing to do with it.

" rest mass remains the same (relativistic effects excluded) but weight varies. "

" The gravitational force, as explained by Newton's Law of Gravitation, is inversely proportional to
the square of the separation between the two masses (or the separation between the centers of
mass for the two objects). "

But that is not true. If you are falling you cannot measure the earth's gravitational force. What Einstein showed is that what Newton called gravitational force is nothing but our own inertia. Inertia is resistance to movement. A free-falling body has no inertia - ergo, it is not really falling!

Now don't ask me what that means; I don't think anybody knows.

• a free falling body - sagefr0g - April 17, 2003 - 04:02 UTC