Skip to main content

Up Next

Habitable Exoplanets Debunked!

Habitable Exoplanets Debunked!

Season 1 Episode 16
10:46
Is Gravity An Illusion?

Is Gravity An Illusion?

Season 1 Episode 17
10:17
How to Signal Aliens

How to Signal Aliens

Season 1 Episode 18
6:14
Can a Circle Be a Straight Line?

Can a Circle Be a Straight Line?

Season 1 Episode 20
8:16
The Leap Second Explained

The Leap Second Explained

Season 1 Episode 21
2:20
Can You Trust Your Eyes in Spacetime?

Can You Trust Your Eyes in Spacetime?

Season 1 Episode 22
9:23
Do Events Inside Black Holes Happen?

Do Events Inside Black Holes Happen?

Season 1 Episode 25
11:50
What if Singularities DO NOT Exist?

What if Singularities DO NOT Exist?

Season 10 Episode 1
14:44
What Happens If We Nuke Space?

What Happens If We Nuke Space?

Season 10 Episode 2
15:13
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
Season
We’ve Been Looking for Aliens for 70 Years. We've Been Doing It Wrong All Along
20:48
Are there no alien signals to find... or do we need to update how we search for them?
We Thought Black Holes Ended in Singularities. They Might End In a Frozen Big Bang
14:27
Physicists hope Planck stars can save us from black hole singularities and paradoxes.
We Found Galaxies Too Old for the Universe
17:41
Galaxies older than the universe? Webb's findings keep defying our best explanations.
Earth’s Core Should Be Impossible. A New State of Matter Explains It.
16:16
Earth's core: solid or liquid? Yes — we know more about distant galaxies than our own interior.
Something Disturbing Happens When You Solve Einstein's Equations This Way
14:42
Gödel found a time-travel solution in General Relativity, revealing spacetime can loop on itself.
Martian Soil Is Deadly. And That's Why It Might Support Life
18:46
Tardigrades can survive almost anything—even most of Mars. But one Martian chemical stops even them.
Is the LHC Creating Dark Matter?
18:18
The Higgs boson may open a portal to hidden particles that could explain dark matter.
Dark Energy Is Driving the Universe Apart. We May Finally Know Why.
19:02
The universe expands faster. “Dark energy” may not be constant after all.
Our Only Chance To Finally Unlock The Gravity Particle
16:26
There’s a new generation of experiments that may unlock the gravity particle.
The Particle We’ve Been Chasing for 30 Years Might Not Exist
18:33
The universe thrums with quantum fields, except something may be missing: the sterile neutrino.
The Universe Itself Might Be Hiding the Gravity Particle From Us
18:42
Gravitons, the particle of quantum gravity, may be impossible to detect.
Heisenberg Made a Discovery in 1925. We Still Can't Explain It
25:02
2025 was the international year of quantum science, but today we examine its origins.
Active loading indicator