John wrote:

I know this has probably been discussed many times but I still haven't
found and answer I can understand. Basic question is why does an apple
fall when I let go of it ?

It falls because you let go of it.
Did you mean "How does the apple fall when it falls ?" ?
Does the apple fall less than the Earth ?

If there was a 'Force' of attraction as Newton described then that is
understandable even though we don't know how the force is generated.
However, relativity says that space-time is curved which explains why
a satellite stays in orbit. Fair enough.

My question is what is space-time doing in the vicinity of a
stationary apple at the time I let go such that it falls towards the
earth since there are no other forces acting on it now? Maybe the
answer is mathematical but an explanation in layman's terms would be
appreciated.

John

On Thu, 21 Aug 2003 08:12:16 -0400, tx6 wrote:



John wrote:

I know this has probably been discussed many times but I still haven't
found and answer I can understand. Basic question is why does an apple
fall when I let go of it ?

It falls because you let go of it.

That's not an answer as to why.

Did you mean "How does the apple fall when it falls ?" ?

No I meant what makes it start to move since it was stationary wrt the
earth, when it was in my hand.

Does the apple fall less than the Earth ?
How much is the earth falling ?

John

Dear John:

"John" wrote in message
...
On Thu, 21 Aug 2003 08:12:16 -0400, tx6 wrote:
....
No I meant what makes it start to move since it was stationary wrt the
earth, when it was in my hand.

The apple does not "start" to do anything. It "stops" being accelerated
off of its elliptical orbit around the Earth's center of mass by your hand.
You on the other hand, continue to be accelerated by lithospheric friction
(dirt). The ellipse described by the apple starts out with ~1000 mph
tangential velcocity (amazingly close to your own), which is wny it appears
to drop straight down. And it departs from your accelerated trajectory
with a second order dynamic (which looks like a constant acceleration).

David A. Smith

On Thu, 21 Aug 2003 07:09:08 -0700, \(formerly\)"
dlzc1.cox@net wrote:

Dear John:

"John" wrote in message
.. .
On Thu, 21 Aug 2003 08:12:16 -0400, tx6 wrote:
...
No I meant what makes it start to move since it was stationary wrt the
earth, when it was in my hand.

Thank you David

The apple does not "start" to do anything. It "stops" being accelerated
off of its elliptical orbit around the Earth's center of mass by your hand.
You on the other hand, continue to be accelerated by lithospheric friction
(dirt). The ellipse described by the apple starts out with ~1000 mph

Where does this acceleration come from ?
Is it the earths rotation ? If so what would happen if the earth was
not rotating ?
Otherwis 1000mph wrt what ?

tangential velcocity (amazingly close to your own), which is wny it appears
to drop straight down. And it departs from your accelerated trajectory
with a second order dynamic (which looks like a constant acceleration.

Still not clear what the apple is actually doing (or doing instead) in
terms of space-time though.

Thanks John

"tx6" schreef in bericht
...


John wrote:

I know this has probably been discussed many times but I still haven't
found and answer I can understand. Basic question is why does an apple
fall when I let go of it ?

It falls because you let go of it.
Did you mean "How does the apple fall when it falls ?" ?
Does the apple fall less than the Earth ?

If there was a 'Force' of attraction as Newton described then that is
understandable even though we don't know how the force is generated.
However, relativity says that space-time is curved which explains why
a satellite stays in orbit. Fair enough.

My question is what is space-time doing in the vicinity of a
stationary apple at the time I let go such that it falls towards the
earth since there are no other forces acting on it now? Maybe the
answer is mathematical but an explanation in layman's terms would be
appreciated.

John

when you go of the apple,it moves towards the earth,because space time is
curved that way,i.o.w.the space where the apple is in when you let it
go,moves to the earth ,and ofcourse the apple moves with it,and this
accelerated,I think this is the best way to see it,
so there is no force or whatever acting on it,
see you,marten

John wrote:

No I meant what makes it start to move since it was stationary wrt the
earth, when it was in my hand.

I will try a non-GR possibility, just out of interest!

The apple and the earth have gravitational fields that, by themselves, are
spherically symmetric but, when close together, distort one another. The
distortion of the field of the apple in the direction of the centre of the
earth, acts like a spring connected between the apple and the centre of the
earth so that, if the apple is released, it moves in the direction that
will reduce
the distortion of its field.

Also, if you throw an apple, it will produce an inertial resisting force
because,
by suddenly moving it, you do not immediately move its entire gravitational
field with it, and so you also cause a distortion of the field that resists
the
motion, like a spring pulling in the opposite direction to the motion to
try
to prevent the distortion.

Since there is no difference in the mechanism of the distortion produced
by gravity and that produced by throwing the apple, inertial mass and
gravitational mass are identical.

Alen