Lenny Susskind hopes to save both unitarity and the equivalence principle. He writes: "
In this paper I’ve made no attempt to prove that ﬁrewalls are absent in all circumstances. Indeed ER=EPR raises the possibility that an angry Alice can hit Bob with a nasty shockwave as he crosses the horizon [10]. What I have assumed is that ﬁrewalls are not inevitable— particularly so if the black hole begins with a smooth horizon—and then asked what new concepts are required to resolve the various paradoxes. In a sense I am trying to turn the ﬁrewall inevitability arguments into arguments for new physical concepts needed to reconcile unitarity and complementarity."
Lenny makes a mistake here in my opinion: "This is a twist on two commonly held incorrect sci-ﬁ ideas; the ﬁrst being that super-luminal signals can be sent through wormholes; and the second that superluminal signals can be sent using entanglement. ER=EPR does not allow superluminal signals, but it gets very close, in the sense that there is no limit on how soon after horizon crossing Bob can receive Alice’s message."
Yes, what he says is true for orthodox quantum theory, but not for its extension that corresponds to traversable wormholes held open with either exotic matter, or couplings to a scalar field as described in current literature cited by Enrico Rodrigo in his Stargate book.
I prefer to keep the equivalence principle and junk unitarity because then we have entanglement signal nonlocality - that's a game changer - Brave New World, Men like Gods and we then understand the physical mechanism for consciousness leading to naturally conscious artificial intelligent androids.
“For years it was thought that the Schwarzschild spacetime did in fact exhibit some sort of radial singularity at r = 2GM/c2. Eventually physicists came to realize that it was not Schwarzschild spacetime that was behaving badly. It was his choice of coordinate system. … the true singularity at r = 0.” P. 126, Enrico Rodrigo, “The Physics of Stargates” (Eridanus Press, New York, 2010). This is true, yet it also does not address an important question. While it is true that a freely falling observer Alice can pass through the event horizon of a large non-rotating black hole without feeling lethal tidal stretch-squeeze Weyl curvature tensor forces, nevertheless the universe will start to look weird to her. More importantly, if Bob is in a spaceship hovering at a fixed distance outside the event horizon with rockets firing radially inward, he will quickly find that there is a minimum distance he can get to without being sucked into the black hole. Indeed, if Bob does not want to exceed a 1g weight that minimum distance is even larger. This is because, the real proper acceleration of hovering, also called the “static LNIF” shoots up to a classical infinity at the event horizon because of the square root of the time-time component g00 that approaches zero at the event horizon in the denominator of the relevant equation in Einstein’s General Relativity. One over zero is infinity. Of course quantum gravity will prevent an actual infinity, but practically speaking that does not change the basic situation. Not only that, but Bob will see a very hot thermal blackbody bath of real photons proportional to his actual tensor proper acceleration that will burn him to a cinder. This will be very peculiar and tragic to Alice who passes close by him in her radial free fall into the black hole. Alice will not feel the heat unless she catches fire etc. from Bob’s burning ship that explodes and flings debris hitting her. This is related to recent speculations by Leonard Susskind et-al on black hole firewalls.
There is a creative tension conflict between Gerard ‘t Hooft’s pontifical proclamation that the S-Matrix must be unitary even in cosmology and Einstein’s equivalence principle that nothing happens to a freely falling observer passing through a horizon g00 = 0 whether that of a black hole whose horizon is observer independent, or whether through our future dark energy de Sitter cosmological horizon, which is observer-dependent. Roughly, unitarity of the S-Matrix of the universe says that there is nothing new under the Sun that quantum information cannot be created or destroyed. This seems to fly in the face of human creativity. Does it really?
http://en.wikipedia.org/wiki/Firewall_(physics)
http://www.scientificamerican.com/article.cfm?id=black-hole-firewall-paradox&print=true
http://www.kavlifoundation.org/science-spotlights/spotlight-live-falling-into-black-holes
http://physics.aps.org/articles/print/v6/115