LIGO black hole echoes hint at general-relativity breakdown
This is super exciting stuff!  We know that the two most accurate models of the physical world, Quantum Mechanics and General Relativity, contradict each other so at least one, and probably both, are approximations to the real laws that govern our universe.  Since the QM and GR disagree about what happens for small massive objects, and in particular black hole event horizons, this is a  place to look for divergence to existing theories.  If these echos holds up under repeated measurements, it could be one of the most consequential measurements of this century.  This is another example of how taking measurements to verify a theory you think you know can lead you in completely unexpected directions.Though, for now, the LIGO team is apparently saying that these results could be the result of noise which would occur 1 out of 270 times.  That's not strong enough evidence (in my mind) to overcome the overwhelmingly likely prior that General Relativity is correct.  In time, we'll see.Also, the article mentions that LIGO has witnessed 3 black hole mergers.  Last I heard LIGO had only witnessed 2.