← Signals
Recordedtimestampscience

GW150914 - two black holes merge and the signal reaches Earth

The two Advanced LIGO interferometers registered a coincident signal sweeping upward in frequency over about a fifth of a second and then cutting off - the inspiral, merger and ringdown of two black holes of roughly thirty-six and twenty-nine solar masses, forming a final hole of about sixty-two and radiating some three solar masses as gravitational waves. The signal arrived at Livingston about seven milliseconds before Hanford. It was the first direct detection of gravitational waves and the first observation of a binary black hole system of any kind; the source lay several hundred megaparsecs away, and the event happened before the detectors' formal observing run had officially begun.

Observed — measured or witnessed, with the observation cited.

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Evidence

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Recorded on Gravitational waves

  1. Einstein presents the field equations of general relativity
  2. Schwarzschild solves the field equations for a point mass
  3. Oppenheimer and Snyder compute continued gravitational contraction
  4. Kerr finds the rotating solution
  5. Penrose proves that collapse to a singularity is generic
  6. Hawking argues that information is destroyed
  7. GW150914 - two black holes merge and the signal reaches Earth
  8. The detection is announced and published

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