Back to Show
PBS Space Time
The Real Meaning of E=mc²
Season 1
Episode 15
You’ve probably known OF E=mc² since you were born, and were also probably told that it meant that it proved Mass equaled Energy, or something along those lines. BUT WAIT. Was E=mc² explained to you properly? Mass equalling energy is mostly true, but E=mc² actually describes a much more interesting aspect of reality.
Support Provided By
17:41
Galaxies older than the universe? Webb's findings keep defying our best explanations.
16:16
Earth's core: solid or liquid? Yes — we know more about distant galaxies than our own interior.
14:42
Gödel found a time-travel solution in General Relativity, revealing spacetime can loop on itself.
18:46
Tardigrades can survive almost anything—even most of Mars. But one Martian chemical stops even them.
18:18
The Higgs boson may open a portal to hidden particles that could explain dark matter.
19:02
The universe expands faster. “Dark energy” may not be constant after all.
16:26
There’s a new generation of experiments that may unlock the gravity particle.
18:33
The universe thrums with quantum fields, except something may be missing: the sterile neutrino.
18:42
Gravitons, the particle of quantum gravity, may be impossible to detect.
25:02
2025 was the international year of quantum science, but today we examine its origins.
21:17
We’ve found lots of “habitable” worlds but we don’t know what factors are needed for life.