The speed at which electromagnetic radiation propagates in vacuum; defined exactly by the 2019 SI as 299 792 458 m/s.
Speed of light in vacuum (c)
Related concepts
- Real numbers (ℝ)
- Vacuum electric permittivity (ε₀)
- Ampère-Maxwell law
- Electromagnetic wave propagation
- Constancy of the speed of light
- Lorentz transformation
- Mass-energy equivalence (E=mc²)
- Einstein field equations
- Real numbers (ℝ)
- Ampère-Maxwell law
- Galactic cosmic rays (GCRs)
- Einstein A and B coefficients
- Time-of-flight particle ID: Δt = (L/c)·(√(1+m₁²/p²) − √(1+m₂²/p²)) ≈ L m₁²/(2p²c) for m≪p