“The so-called hair-theorem maintains that they can be entirely described by three parameters: mass, angular momentum, and electric charge. They have no bumps of defects, no idiosyncrasies or imperfections – no ‘hair’.”

In “Einstein's Shadow: A Black-Hole, a Band of Astronomers, and the Quest to See the Unseeable” by Seth Fletcher

“There are actually three principles that come into conflict at a black-hole horizon: Einstein’s equivalence principle, which is the basis of general relativity; unitarity, which requires that the equations of quantum mechanics work equally well in both directions; and locality. Locality is the most commonsense notion imaginable; everything exists in some place. Yet it’s surprisingly hard to define locality with scientific rigour. A widely accepted definition is tied to the speed of light. If locality is a general condition of our universe, then the world is a bunch of particles bumping into one another, exchanging forces. Particles carry forces among particles – and nothing can travel faster than the speed of light, including force carrying-particles. But we know that locality sometimes breaks down. Entangled quantum particles, for example, would influence one another instantaneously even if they were in different galaxies. […] And after all, the whole reason black holes hide and destroy information is because of the principle of locality – nothing can travel faster than the speed of light, and therefore nothing can escape a black hole. If some sort of non-local effect could relay information from inside a black hole to the outside universe, all was well with the world.”

In “Einstein's Shadow: A Black-Hole, a Band of Astronomers, and the Quest to See the Unseeable” by Seth Fletcher


“The 20th century produced two spectacularly successfully theories of nature: general theory of relativity, and quantum theory. General relativity says the world is continuous, smoothly evolving, and fundamentally local: influences such as gravity can’t travel instantaneously. Quantum theory says the world is twitchy, probabilistic, and non-local – particles pop in and out of existence randomly and see to subtly influence one another instantly across great distances. If you’re a scientist who wants to dig down tot eh deepest level of reality, the obvious question is: which is it?”

In “Einstein's Shadow: A Black-Hole, a Band of Astronomers, and the Quest to See the Unseeable” by Seth Fletcher

 

 

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