It's hard to answer, because the question is so open. That means the answer can be yes.....and can be no.
For instance....if the earth was flat, there would be no life. And with no life, no man.....and with no man....no math. And no equation.
And for instance......the math relationship of E=mc2, is correct, whether there is life or not.
And.....and for instance....the relationship is true.......but no one knows why. And the reason no one knows why.......is because the term E........can mean many many things. And the term m can be many, many things.
The terms E and m have too many mushy concepts and mushy definitions.
If one could specifically define the terms, E and m, we might be able to express the correct dynamic. But as of right now, both E and m have multiple dynamics. And depending on what dynamic is used........E=mc2 can mean many different things.
And it appears, modern science likes it that way. Slimey.
But the truth is simple. E is simply...motion. Any and all motion is energy. And mass is a special kind of motion. Mass is confined motion. The more one confines the motion, the greater the mass. That's the see-saw of energy and mass.
To answer your question, one has just to prove that the earth is flat.
Mathematically, a surface is flat if one dimension stay constant when to two others change.
If you locate every point on the surface of the earth by its longitude, latitude and distance from the center of the earth - a perfectly valid set of coordinate equivalent to your length, width, height (i.e. every points anywhere can be converted from one set of coordinate to the other, without loosing information) - then I can claim the surface of the earth is flat (in the former set of coordinate, distance to the center of the earth stay constant whatever longitude and latitude).
E is still equal to mc2, so your question is answered.