The speed of light in a vacuum is constant and independent of the reference frame
the verdict
SUPPORTED
the evidence backs this
confidence 75/100
The principle that the speed of light in a vacuum is constant and independent of the reference frame is firmly established by physical theory, group-theoretic symmetry, and foundational postulates of relativity.
Evidence for · 3
The Dirac-Einstein Photon Model of Electron
2026 · cited by 0
Supports the constancy of the speed of light and validates the first postulate of Special Relativity through a photon model of the electron.
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More for · 2
Constancy of the Speed of Light as a Theorem: Why Only Dynamically Supported Spacetime Can Sustain a Finite Invariant Speed
2025 · cited by 0
Demonstrates that the constancy of the speed of light is equivalent to a Lorentzian conformal structure in spacetime.
Einstein’s Second Postulate: Sufficient but Not Necessary
2025 · cited by 0
Shows how the invariance of the speed of light can be derived from symmetry principles as a robust physical parameter.