Mass can transform into energy, and energy can transform into mass, in accordance with Einsteins equation E

Question:

Mass can transform into energy, and energy can transform into mass, in accordance with Einstein’s equation E = mc². If the amount of mass–energy in the universe remains constant, what happens to the amount of space within the universe? What, then, is happening to the density of the universe?

Fantastic news! We've Found the answer you've been seeking!