Led by Laurent Lellouch of France's Center for Theoretical Physics, the group of physicists used some of the world's strongest supercomputers to establish the calculations for estimating the mass of protons and neutrons, the particles at the nucleus of atoms.

Proposed in his Special Theory of Relativity in 1905, Albert Einstein's e=mc2 formula shows that mass can be converted into energy and vice versa. And although the theory has only now been corroborated, that hasn't stopped it from being used frequently, perhaps most notably as the basis for building atomic weapons.

"Until now, this has been a hypothesis," France's National Center for Scientific Research (CNRS) said about Einstein's equation in a press release.

The computations that the team of scientists worked out involved "envisioning space and time as part of a four-dimensional crystal lattice, with discrete points spaced along columns and rows."