What If The Speed of Light Were NOT CONSTANT?
Summary
This episode investigates whether the speed of light has varied in the past or across the universe, exploring Variable Speed of Light (VSL) theories proposed by physicists like Robert Dickey and John Moffat. The hosts discuss how VSL models attempt to explain cosmic phenomena such as the horizon problem and dark energy, but face significant challenges due to conflicts with Lorentz invariance and CPT symmetry. The discussion concludes that while relativity remains robust, questioning its axioms is essential given its clash with quantum mechanics. The episode also includes detailed responses …
Topics discussed
Introduction: Is the speed of light truly constant?
Lorentz invariance and the foundations of relativity
Why physicists doubt variable speed of light theories
The definition of units and the photon clock thought experiment
Time dilation and the coupling of space and time
Quantum scales and the first VSL theory by Robert Dickey
Gravity as a change in light speed vs spacetime curvature
The horizon problem and cosmic inflation
VSL as an alternative to inflation and dark energy
Specific VSL models: Moffat, Albrecht, and energy dependence
Testing VSL via the fine structure constant
The necessity of Lorentz invariance for causality
CPT symmetry violations and refractive index analogies
Conclusion: The status of variable speed of light theories
Missed comment responses and a correction on Stan Brodsky
Comment response: Stirring superfluids and vortices
Comment response: Moving the Sun and planetary orbits
Comment response: Detecting spacecraft via gravitational waves
Comment response: Supernova radiation and planetary shielding
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