The underside of the mantle would actually be a mirrored image of the earth's outside surface.
New findings of the makeup of the underside of earth's mantle is found it to be an upside-down version of our planets outer surface.
Lets look at some of sciences latest findings about our mysterious Earth:
According to a report published in the Los Angelas Times on December 14, 1996 "Huge Mountains and Valleys were found at the "core" - mantle boundary." In 1994 California Institute of Technology geophysicist Brad Hager reported to the American Geophysical Union's annual meeting, "The boundary between Earth's molten-iron core and the underlying rock mantle may be an upside down version of the planet's surface." Almost word for word - except for the molten part - what Gardner claims in his 1913 book.
As one Associated Press science reporter put it
, "The new research which Hager and other scientists will outline this week at the… meeting further complicates the traditional simplistic picture that Earth's thin crust surrounds a thick, solid rock mantle, which in turn surrounds a molten-iron core".
Not so the Hollow Earth Theory. The 1994 findings of "continents, mountains and valleys" on the underside of the mantle are a major part of Gardner's 1913 theory. This part of his theory stands firm and no one can deny that this part of the hollow earth theory has been proven to be science fact.
Here's another. According to reports published July 1996 in The New York Times and other newspapers around the country:
"Dr. Xuedong Song and Dr. Paul Richards, seismologists at Columbia University's Lamont-Doherty Earth Observatory in Palisades NJ have discovered that "the Earth's core is spinning freely and slightly faster than the rest of the planet"… According to the scientists the "moon size" inner core is moving fast enough to lap the surface once every 400 year. The scientists were also quoted as saying, "this makes it [the center core] virtually a planet within a planet". However if, as even establishment scientists would agree, the core is molten and hot then it must give off light. That's more like "a small sun within a planet," just as Gardner visualized.
Today the only difference between Gardner's Hollow Earth Theory and the accepted Theory is that the establishment theorizes there is a molten outer core between the inner core (sun) and the crust. Gardner says there is an atmosphere in that section.
However, by using only known scientific facts in the equation anyone with an open mind can realize either theory could be right. And those who have been studying the subject for any length of time will realize that, while the accepted theory has changed numerous times since 1913, Gardner's Hollow Earth Theory has never changed … just a long series of new scientific findings to support it. Hollow? Solid? Somewhere in between? No one knows for sure. After all, bottom line - it's all just theory.