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Re: [pygame] Why does my ball vibrate?



Ian Mallett wrote:

If the ground were mobile, that gravity force down would cause the
earth to move down with that same force.  Since the earth can't move,
it pushes back with the force of gravity.
But the Earth does move.  If you drop a 1kg. ball from a height of one
meter, then both objects (the ball and the Earth) accelerate towards
each other.  The reason we see the ball fall is because 1), we move
with it, and 2) the Earth is more massive and so is accelerated very
little by the force.  (In fact, the Earth accelerates:
(1 kg.)/(5.9736×1024 kg.)
= .1674^ -1024th as much.  Not even a trillion trillion trillionth of
a millimeter.  Still much smaller than even that.  As soon as I get a
minute, I'll do some more demos...

This is less than the Planck length of 1.6 * 10 ** -35 meters so becomes moot. The Planck length would make a natural cutoff for any game physics. :-)

--
Lenard Lindstrom
<len-l@xxxxxxxxx>