On 10/24/2010 10:33 PM, Mauro Lacy wrote: > ... > We'll probably never know for sure what forces are really exerted > inside a solid mass, due to the simple fact that bodies don't move > inside solids. Measurements of acceleration and velocity in the > gaseous giants, or in Venus's atmosphere, can be very interesting to > analyze. The problem would be drag, of course. Even if the density > gradients can be adequately modeled, I assume drag would be very > difficult to model.
I was thinking that instead of in the gas giants or in Venus, experiments can also be done in Earth's oceans, in deep lakes, or even in abandoned drilling holes. If drag is difficult to model adequately, a static instead of kinematic approach can be attempted. Putting a sensitive gravimeter inside a containment chamber, and sinking it to the depths of the ocean, registering the intensity of the gravitational field at different depths, should yield very interesting results, which will probably be unexpected and anomalous based in current theory. Particularly, I predict that the intensity of the gravitational field under the surface will continue to take the form of an inverse square law; that is, will follow a non-linear variation, contrary to current theory. Take into account that, playing with different density models for the Earth's core and mantle, current theory can model the actual increase in gravity under the surface. See http://en.wikipedia.org/wiki/Newton%27s_law_of_universal_gravitation#Bodies_with_spatial_extent and particularly http://en.wikipedia.org/wiki/File:Earth-G-force.png What current theory will not be able to model, at least without resorting to exotic density models, is the form of the curve. That is, experiments should focus in the form of the curve more than in the increase of the field in itself, because the increases can be easily explained/modeled with adequate density gradient ratios for the core/mantle. The next step would be to see how exotic the density models must be to explain the results within standard theory, and particularly, if they agree with known density data for the crust and outer mantle, if that is available. I don't know much about gravimeters, by the way, but this seems to be an experiment that is not completely out of reach for the determined and resourceful amateur. Regards, Mauro
