Re: Jupiter has no surface that we know of

[David Williams]

-> Starting at some point close to center, the gravity is not only near
-> zero but continually pulling you away from the actual center of
-> whatever planet or moon. It can't be any other way unless the core
-> started off as worth something of far greater density than anything
-> artificially or otherwise compressed.

Within a uniform hollow spherical shell, the force of gravity exerted
by the shell is ZERO. The force pulling in any direction is balanced by
an equal force pulling in the opposite direction.

A spherical body such as a planet can be considered as a set of
concentric shells. Within the planet, the force of gravity at any point
is produced only by the shells that are closer to the centre than is the
point under consideration. The shells further from the centre produce
no net force, since the point is within them.

So the force at any point within a planet is produced by the material
that is closer to the centre than is the point. So the force must be
directed *toward* the centre. However, as the centre is approached, the
force diminishes, since less material is producing it. Exactly at the
centre, the force is zero.

I learned how to prove this in high school. It's a simple exercise in
calculus. I guess you haven't got that far yet.

dow

[Ralph]

You might want to consider these ideas in a pulp science fiction group. I
suspect even they don't choose to go that way too often. - and I like sci fi
on TV, when it's good.
Denying the basic physics of pressure, gravity, and chemistry in planet
science makes it impossible to discuss with you reasonably.
You seem to know the word "calculus", but not how to use it.

Oh, and changing your e-mail doesn't mean that anyone who read even one
sentence from you
"David Williams" <david.w...@bayman.org> wrote in message
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