Quote:
Originally Posted by bojan
If the big mass collapsed into smaller volume (increasing density), the field strength at the place where small mass is (was) is still the same.
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Hi Bojan;
This is similar to Gauss' Law for electric fields:
"The electric flux through any
closed surface is proportional to the enclosed electric charge."
The smaller 'closed surface', encloses more 'field lines', (for a constant charge or gravity), thus the field strength goes up as the radius (r) of the 'closed surface' decreases. If the point mass stays at the same place, the potential difference between where the point is and where the shrunken 'closed surface' now is, is greater and thus results in a greater attractive force on the point. Hence a greater force is needed for it to escape.
The 'closed surface', I think, is the key in the model. The numbers of field lines passing thru this surface determines the field strength.
Hope this helps.
Cheers