Doctor Drivel wrote:

"ThinAirDesigns" wrote in message
...
Doctor Drivel
It does not go down it goes UP.

Of course the lighter than air balloon is going up; it has no choice
-- gravity is forcing it UP.

So if defies gravity.

Something doesn't defy gravity just by going up.

Suppose you have a jar half full of syrup. The syrup occupies
the bottom half. There is air in the top half.

Now turn the jar upside down. It's OK, the lid is closed.
What heppens next is that gravity forces the syrup down and the air up.
So they both *obey* gravity. The air does not defy it.

A helium filled balloon goes up because gravity is pulling on the
air around and above it more strongly than on the balloon itself.

Put the balloon in a car, and a football on the back seat. Drive
round a corner quickly, and the football will shoot off to one side,
and the balloon to the other. Both items are obeying, not gravity
this time, but a similar phenomenon, inertial acceleration.