Jan Lamprecht's Hollow Earth

Using Newton's shell theorem as it relates to gravity, we come to the conclusion that there is no gravitational force at the center of large bodies like moons, planets and stars.

As a consequence, all these bodies are likely to be hollow. A cavity, once formed at the center of such a body, will have no way of disappearing.

There will be enormous pressure in the walls surrounding such a cavity, but that in itself is no reason to believe that the cavity will collapse. If a part of the internal wall should come loose, the cavity will not become smaller. The loose matter will simply float about in the atmosphere of the cavity.

Unless the entire planet collapsed in on its internal cavity, the cavity will remain.

Cross section of a hollow planet

An important point that can be gleaned from Newton's shell theorem is that there will be an overall tendency towards less density at the center of large bodies. The theorem implies a one way mechanism in which things can become less dense at the center, but never more dense.

High density matter expelled from the core will not return. Low density matter will tend to stay.

This means that planets can be modeled as being at their most dense at some distance from the center, after which they become less dense.

When Jan Lamprecth wrote his paper on hollow planet seismology vs. solid Earth seismology, he noted that this kind of planets will yield the easiest and most straight forward explanation for seismic data.

Jan Lamprect concluded therefore that Earth is hollow, with a low density interior wrapped in a high density crust.

This happens to be the exact same conclusion that we can draw from an open minded consideration of Newton's shell theorem as it applies to planets.