How We Know The Earth Is Ancient

In astronomy we talk about billions of years like it’s no big deal. But how can we be sure about timescales so far beyond the capacity for human intuition? Our discovery of what we now call deep time is very recent - as recent as our discovery of the true spatial vastness of our universe. And it came as scientists tried to measure the age of the Earth. What they found was shocking and humbling.

Season 6 Episode 11 Length 13:38 Premiere: 04/07/20

Recent Episodes

Is the LHC Creating Dark Matter?

S11 E23 Length 18:18 Premiere Date 03/05/26

Dark Energy Is Driving the Universe Apart. We May Finally Know Why.

S11 E22 Length 19:02 Premiere Date 02/19/26

Our Only Chance To Finally Unlock The Gravity Particle

S11 E21 Length 16:26 Premiere Date 02/05/26

The Particle We’ve Been Chasing for 30 Years Might Not Exist

S11 E20 Length 18:33 Premiere Date 01/22/26

The Universe Itself Might Be Hiding the Gravity Particle From Us

S11 E19 Length 18:42 Premiere Date 01/13/26

Heisenberg Made a Discovery in 1925. We Still Can't Explain It

S11 E18 Length 25:02 Premiere Date 12/11/25

Specials

Black Holes. Explained. For 1.5 Hours.

Length 1:38:18 Premiere Date 12/18/25

Strange Stars

Length 09:58 Premiere Date 03/01/17

Did Dark Energy Just Disappear?

Length 12:22 Premiere Date 02/16/17

The Many Worlds of the Quantum Multiverse

Length 12:52 Premiere Date 02/09/17

The First Humans on Mars

Length 07:51 Premiere Date 02/02/17

Life on Europa?

Length 09:37 Premiere Date 01/18/17

Self-Replicating Robots and Galactic Domination

Length 09:57 Premiere Date 12/25/16

Season 6 Episodes

Show Episodes

Show Clips & Previews

The Arrow of Time and How to Reverse It

S6 E36 Length 10:36 Premiere Date 11/18/20

Can Free Will be Saved in a Deterministic Universe?

S6 E35 Length 13:42 Premiere Date 11/11/20

Electroweak Theory and the Origin of the Fundamental Forces

S6 E34 Length 13:48 Premiere Date 11/04/20

How The Penrose Singularity Theorem Predicts The End

S6 E33 Length 12:50 Premiere Date 10/27/20

Is The Future Predetermined By Quantum Mechanics?

S6 E32 Length 12:39 Premiere Date 10/20/20

Do the Past and Future Exist?

S6 E31 Length 13:09 Premiere Date 10/13/20

Venus May Have Life!

S6 E30 Length 13:01 Premiere Date 10/05/20

Solving Quantum Cryptography

S6 E29 Length 14:39 Premiere Date 09/28/20

Could Life Evolve Inside Stars?

S6 E28 Length 10:47 Premiere Date 09/21/20

The Truth About Beauty in Physics

S6 E27 Length 13:29 Premiere Date 09/08/20

How Do We Know What Stars Are Made Of?

S6 E26 Length 11:13 Premiere Date 09/01/20

Can Future Colliders Break the Standard Model?

S6 E25 Length 13:42 Premiere Date 08/24/20

How Stars Destroy Each Other

S6 E24 Length 10:41 Premiere Date 08/17/20

The Boundary Between Black Holes & Neutron Stars

S6 E23 Length 11:22 Premiere Date 07/20/20

Does Antimatter Explain Why There's Something than Nothing

S6 E22 Length 12:43 Premiere Date 07/20/20

Dissolving an Event Horizon

S6 E21 Length 11:32 Premiere Date 06/30/20

Building Black Holes in a Lab

S6 E20 Length 13:12 Premiere Date 06/22/20

What Happens After the Universe Ends?

S6 E19 Length 14:34 Premiere Date 06/15/20

Can Viruses Travel Between Planets?

S6 E18 Length 13:58 Premiere Date 06/08/20

Does Gravity Require Extra Dimensions?

S6 E17 Length 12:41 Premiere Date 05/27/20

Mapping the Multiverse

S6 E16 Length 14:21 Premiere Date 05/18/20

How Luminiferous Aether Led to Relativity

S6 E15 Length 13:52 Premiere Date 05/11/20

How We Know The Universe is Ancient

S6 E14 Length 14:01 Premiere Date 05/04/20

Will Wormholes Allow Fast Interstellar Travel?

S6 E13 Length 14:31 Premiere Date 04/22/20

Was the Milky Way a Quasar?

S6 E12 Length 13:31 Premiere Date 04/14/20