https://www.youtube.com/watch?v=Fprjlcmvnbo
This video comes right around the time that Pulsars and Quasars were first hinting that impossible to account for physical objects exist. Only by Einstein's General theory of Relativity and it's predictions of black holes can account for these things(black holes are just one step beyond pulsars/neutron stars). Also, black holes and even the Big Bang theory hint that quantum mechanics and General Relativity need to be combined into a single theory. This has yet to be done. Recently, physicists have become excited about explain spacetime with quantum mechanics 'entanglement' which has recently been experimentally confirmed(actually, entanglement was confirmed back in the early 1908s by Alain Aspect).
As I remarked to a mathematician friend of mine, we know quantum mechanics and General Relativity have to be combined. Entanglement is a part of quantum mechancis; finding the relation of entanglement to General Relativity has to be bare fruit!
