Does the Planck Length Disrupt E=MC^2?
Sep 16, 2026 · 25m
Summary
This episode explores Doubly Special Relativity, a theory proposing that the Planck length remains invariant for all observers to resolve conflicts between quantum mechanics and general relativity. By modifying the standard dispersion relation, this framework suggests potential violations of energy conservation and energy-dependent light speeds. The discussion covers experimental constraints from gamma-ray bursts and the absence of vacuum Cherenkov radiation, which currently limit the strength of these proposed effects.
Topics discussed
Sponsor: LinkedIn ad campaign results
Sponsor: Uber Eats game day delivery
Intro: Extending Einstein's equation
Galilean relativity and Newtonian mechanics
Einstein's fix: Special relativity and Lorentz factor
Conflict between General Relativity and Quantum Mechanics
Sponsor: LinkedIn and Uber Eats
Planck units and the scale of quantum spacetime
The problem of invariant Planck length
Doubly Special Relativity (DSR) proposal
Sponsor: LinkedIn ad metrics
Sponsor: Uber Eats game day delivery
Modified dispersion relation (MDR) explained
Breaking energy and momentum conservation
Testing DSR: Photon pair production
Astrophysical constraints on photon decay
Vacuum Cherenkov radiation
Energy-dependent speed of light
Gamma ray burst observations and limits
Conclusion: Current status of DSR
Black Hole Friday merch sale promotion
Sponsor: Citizens Bank and SVB
Sponsor: McDonald's spicy McNuggets
Listen ad-free on Castria