I am trying to understand special and general relativity and I want to make sure that I didn't miss a physical ("real") phenomenon that is described by their equations, including the implied older predictions and explanations from Newtonian physics. The ones I know of are:

  • Constant speed of light (and absence of simultaneity)

  • Time dilation

  • Length contraction

  • Gravitational "force"

  • Gravitational time dilation

  • Gravitational lensing

But I am pretty sure I am missing some if not a lot of other phenomena.

  • $\begingroup$ Gravitational waves. I don't know if that makes a full list, but everything that comes to mind is from applying the listed behavior to specific circumstances. $\endgroup$ May 24, 2017 at 5:56
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    $\begingroup$ I'd like to make clear that relativity doesn't explain constance of the speed of light. It postulates it. In fact that is the starting point of special relativity $\endgroup$ May 24, 2017 at 6:47

1 Answer 1


Here's a list of various effects then (I might add more later on)

Measured effects for special relativity :

  • The constancy of the speed of light, as measured by the Michelson-Morley experiment.
  • Time dilation/length contraction of two observers in motion relative to each other, as measured by cosmic muon decay rates and atomic clocks on airplanes
  • The relativistic energy momentum conservation laws, as verified by scattering expeirments.
  • The relativistic Doppler effect, measured by the Ives–Stilwell experiment
  • The (local) isotropy of space, as measured in the Hughes–Drever experiment
  • The Sagnac effect, where the travel time of two light rays going in opposite directions is different if there is rotation involved, as measured in the Fizeau experiment.
  • Relativistic corrections to quantum mechanics, such as the Lamb shift
  • CPT invariance for quantum field theory, so far holding for all measurements.
  • Lorentz invariance leading to a lack of the anomalous dispersion of light, measured on far off light sources

Other special relativistic effects :

  • The relativistic aberration

Measured effects for general relativity :

  • All predictions of classical gravitational theory (within some limits). These include :
    • Attraction of two masses, as measured in the Cavendish experiment and the Schiehallion experiment
    • The equivalence principle (objects dropped in a vacuum fall at the same rate), as confirmed in the Eötvös-Dicke experiment
    • Tidal forces
    • Shifting in quantum energy levels, as measured by ultra cold neutron experiments
  • Light deflection around stars, as measured by Eddington.
  • More generally, gravitational lensing, such as observed in the Einstein cross.
  • The precession of the perihelion of Mercury
  • Redshifting of light in a gravitational field, as measured in the Pound-Rebka-Snider experiment and in measurements of the spectrum of Sirius B.
  • Time dilation in gravitational fields
  • Frame dragging and geodetic precession, as measured by Gravity Probe B
  • Gravitational waves, both indirectly by loss of energy in binary star systems and directly with LIGO
  • The cosmological expansion of space, as measured by the redshifting of galaxies.

Effects that are currently not experimentally verified :

  • Unruh radiation, where an accelerated observer will measure radiations where none exist for an observer at rest.
  • Hawking radiations where an event horizon radiates thermal particles.
  • The photon sphere around a black hole, which the Event Horizon Telescope will attempt to measure
  • Creation of particles by non-static spacetimes (for instance by the cosmological expansion)

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