"Hagar" wrote in message
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"G=EMC^2 Glazier" wrote in message
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On the Earth's surface gravity is the strongest. Strongest as
measured by objects not sitting on the earth's surface? Go figure Bert


If you think of gravity as radial lines emanating from the center of the
Earth, then a fixed amount of these imaginary lines will intersect a human
body, at any given point on the Earth's surface, giving your body a specific
weight, based on the components of your body and their combined atomic mass.
Since these lines are actually fanning out, 1000 miles above the surface
much less of them will intersect your body, thus reducing your body weight..
Conversely, if you could go 1000 miles below the surface, there would be
more lines intercepting your body than on the surface and thus increasing
your weight.

Bert's wrong again, as usual. If the Earth were composed of a
uniform density material then he would have been correct, but
it is not.

The Earth's makeup is not uniform; there are distinct layers of
differing density and thickness. Since the gravitational
potential depends upon both mass and distance, a graph of the
acceleration due to gravity with respect to radial distance from
the center is not a simple smooth curve, and in fact it peaks at
about 1.08 g at a radius of about 3600 km (in what is refered
to as the D'' layer sandwiched between the Outer Core and the
Lower Mantle). There is a second, smaller peak of 1.01 g in the
Transistion Region just below the Upper Mantle around R = 5860km.