Oct 24, 2026 · 16 min · 11 segments
Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/DonateSPACE Uploaded 10-08-17 Could it be that all…
Matt O'DowdHost
For example, the idea that every electron in the universe is really the one same electron traveling forwards and backwards in time.

In the spring of 1940, the great physicist John Archibald Wheeler had a flash of insight.

The fateful conversation began, Feynman, I know why all electrons have the same charge and the same mass.

Wheeler went on to describe his one electron universe idea, that there exists only one electron, and that electron traverses time in both directions.

eventually traversing the entire past and future history of the universe in both directions and interacting with itself countless times on each pass.

When the electron is moving backwards in time, It's a positron, the antimatter counterpart of the electron.

However, Richard Feynman did take at least one aspect very seriously, the mathematical equivalence of antimatter as time-reversed matter.

In fact, it was Swiss physicist Ernst Stuckelberg who first proposed this idea in the 1930s.

But Wheeler's one electron universe idea inspired Feynman to build this representation of antimatter into his path integral formulation and the following spacetime interpretation of quantum mechanics.

The one electron universe was motivated by an odd fact about electrons that had troubled Wheeler, that they are all identical.

Wheeler's notion was that if electrons behave as though they are identical, perhaps they truly are, to the point of being identically the same entity.

It exists as a line traced by its passage through space and time, rather than as a point-like particle at one instant in time.

The point, like electron, is just a segment of that world line if we take a slice through spacetime at one instant in time.

The direction of an electron's world line can shift as the electron is scattered by photons.

For example, the idea that every electron in the universe is really the one same electron traveling forwards and backwards in time.

In the spring of 1940, the great physicist John Archibald Wheeler had a flash of insight.

The fateful conversation began, Feynman, I know why all electrons have the same charge and the same mass.

Wheeler went on to describe his one electron universe idea, that there exists only one electron, and that electron traverses time in both directions.

eventually traversing the entire past and future history of the universe in both directions and interacting with itself countless times on each pass.

When the electron is moving backwards in time, It's a positron, the antimatter counterpart of the electron.

However, Richard Feynman did take at least one aspect very seriously, the mathematical equivalence of antimatter as time-reversed matter.

In fact, it was Swiss physicist Ernst Stuckelberg who first proposed this idea in the 1930s.

But Wheeler's one electron universe idea inspired Feynman to build this representation of antimatter into his path integral formulation and the following spacetime interpretation of quantum mechanics.

The one electron universe was motivated by an odd fact about electrons that had troubled Wheeler, that they are all identical.

Wheeler's notion was that if electrons behave as though they are identical, perhaps they truly are, to the point of being identically the same entity.

It exists as a line traced by its passage through space and time, rather than as a point-like particle at one instant in time.

The point, like electron, is just a segment of that world line if we take a slice through spacetime at one instant in time.

The direction of an electron's world line can shift as the electron is scattered by photons.
The rest of this transcript — segmented and speaker-labeled, so you land on the exact moment something was said
Search every transcript — by keyword, by phrase, or by meaning, across every show Radar indexes
Trends — what is surging across podcasts, measured against its own baseline
Alerts — when a name you follow appears in a newly indexed episode
No account is needed to search Radar.