A government insider who worked in an underground installation near the Groom Lake (Area 51) base in Nevada, speaks from his understanding and personal experience about government knowledge of the inner realms of planet earth. He acknowledges Admiral Byrd's flight into the inner realms as well as the very warm area surrounding the approximately 50 mile diameter opening with flora and fauna at the earth's polar regions. He also discusses the fleets of UFOs or unexplained craft that emerge from these openings on a regular basis that are closely monitored by the governments on the surface.
Perhaps most importantly and most interesting is his acknowledgement of our governments' understanding of the fallacies in the mainstream concepts of the nature of gravity. The insider makes claims of having been briefed on the true nature of gravity and that gravity is not an inherent property of matter but is rather magnetic in nature and stems from the emanations of our sun. This revelation dovetails nicely with the ideas of 'push gravity' and removes the main argument scientists have against hollow earth.
Video 1, Video 2, Video 3