In Brief
  • We're all most likely familiar with the equation, but what does it really mean?
  • This video by PBS Space Time helps to explain.

Albert Einstein remains one of the greatest minds in history. His contributions to the fields of cosmology, physics and mathematics are unquantifiable, but arguably, the most important works were his theories of general and special relativity.

Ultimately, they shed light on the intimate workings of the universe—from the nature gravity itself, to the outermost edges of black holes. Somewhere along the way, he proposed what is now one of the most famous equations of all time: E=mc².

If most people were to sum it up, they would say that the equation deals with the Mass–energy equivalence, which tells us that energy and matter are fundamentally the same thing. And it does, but is that really all it says? No, as it turns out, absolutely not. PBS Space Time gives a mind-bending explanation:

WATCH: “The Real Meaning of E=mc²”