The Transparent Sun as a Gravitational Lens: Hollows in the Outer Solar System Less well known than the Sun's minimum ``opaque" focus at 550 AU is its minimum ``transparent" focus at about 25 AU. What, though, is focused there? No one knows for sure. Interestingly, this outer Solar System distance, just beyond the orbit of Uranus, is reachable with current technology. Strange thin tubes here dubbed ``hollows" might exist out there where radiations (particles) and even fields might be detectably magnified by the gravitational lens effect of the transparent Sun. We report on hollows potentially generated by the Sun and their detectability. Here recent theoretical results are reported on whether gravity itself can be enhanced creating unusual ``gravitational hollows" of slightly enhanced gravity in the outer Solar System. R. J. Nemiroff, B. R. Patla (Michigan Tech) First hollows paper in press: Nemiroff, R. J, 2005, Astrophysical Journal, 628, 1081.

Static Electric and Magnetic Fields follow photon geodesics and so are focused E & M effects are well characterized in General Relativity (GR) [1] Electric and Magnetic Hollows would exist if the Sun were electrically neutral Black holes (electrically neutral) therefore create Electric and Magnetic hollows (previously never discussed) [1] See, for example, De Felice F. & Clarke, C. J. S. 1990, Relativity on Curved Manifolds, Cambridge U. Press, p 231, and references therein.

Focused energy creates hollows anyway Light and any emitted radiation would be focused outside of 25 AU and create a maximum in energy density and pressure. This peak itself creates a gravitational hollow like entity. As energies are small, this effect is thought to be small compared to maximal non-pressure (zero Temperature) effects.

Does GR predict Gravitational Hollows? It is still unknown. The two body problem is notoriously difficult in GR. We are working on the on-axis problem but have yet to find a solution or even a solvable mathematical approach to the problem. Top GR pundits consulted disagree, are unsure either way, or are reluctant to comment. All agree that the gravitational hollow effect has never been looked for and so represents a new test of gravity regardless of what GR predicts.