Did the black hole paradox really come to an end? Rob Sheldon offers some thoughts

A recent science media story claimed as much:

In a series of breakthrough papers, theoretical physicists have come tantalizingly close to resolving the black hole information paradox that has entranced and bedeviled them for nearly 50 years. Information, they now say with confidence, does escape a black hole. If you jump into one, you will not be gone for good. Particle by particle, the information needed to reconstitute your body will reemerge. Most physicists have long assumed it would; that was the upshot of string theory, their leading candidate for a unified theory of nature. But the new calculations, though inspired by string theory, stand on their own, with nary a string in sight. Information gets out through the workings of gravity itself — just ordinary gravity with a single layer of quantum effects.

George Musser, “The Most Famous Paradox in Physics Nears Its End” at Quanta

Our physics color commentator Rob Sheldon offers,

I have previously reported on why certain branches of physics are in stalemate, such as the search for “dark matter particles”. Unfortunately we come to yet another field in the same condition.

Black Holes are a theoretical and empirical disaster. Given two possible assumptions to Schwarzschild’s solution of Einstein’s gravity equation, nearly everyone has taken the discontinuous, unphysical, “event-horizon” assumption leading to “Black Holes”. One of the many predictions of BH, is that they cannot have magnetic fields, and they destroy anything that falls into them, converting all that matter into “Hawking radiation”.

What about all that data showing high density objects at the center of our galaxy and neighboring galaxies?

None of that data actually measure the “black hole density”, because they don’t have the resolution to “see” the event horizon. The better solution to Schwarzschild produces high density objects that are 15% larger than BH, but the best images returned by astronomers have a resolution about 3x larger than the event horizon. So yes, there’s a high density object there, but we can’t tell yet if it is a fat neutron star or a black hole.

But we have reasons to believe that these objects are not BH. Not only have nearly all BH candidates been observed to have magnetic fields, but Hawking radiation has never been observed either. This led the Nobel Prize committee to withhold awarding a “discovery of black holes” prize, until 3 years ago, when the LIGO consortium reported the observation of gravity waves from the merger of 2 BH and was awarded the Prize. Belatedly, the committee realized that they had never awarded a BH prize, so this year Penrose and 2 astronomers were awarded the prize for BH.

Despite the handwaving over magnetic fields and the unobserved Hawking radiation, there was a third problem with BH. If they destroyed matter and spit out radiation, then they also destroyed information. And information for physicists is just entropy, the stuff that keeps perpetual motion machines from running. So if BH can be so cavalier about entropy, the universe supports perpetual motion. This so unnerved Leonard Susskind that he debated Stephen Hawking for 10 years, finally writing a book “The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics”

His battle was won by Hawking declaring, just before he died, that he no longer believed in BH. An alternate approach would have been for Stephen to stop believing in Hawking radiation–but it was a bridge too far. However, that was the approach of this recent consortium that attempted to “entangle” the Hawking radiation to account for information loss. The article in quanta magazine does as good a job as anyone could explaining such material, but they don’t evaluate the succession of assumptions. So here’s a quick list:

a) assumption of event horizon solution (everyone else does it)
b) assumption of anti-deSitter universe (which is known to be wrong, Hossenfelder hates it too)
c) assumption of AdS <–>CFT duality (a string theory assumption everyone else makes too)
d) assumption that deleting excess radiation solves the AdS problem (no one has a clue if this is legal)
e) assumption of “replica” to solve thermodynamics on spacetime (sounds like the controversial H-theorem again)
f) assumption of path-integral for QM gravity (failed attempt from the 60’s addressing QM<->GR incompatibility)
g) assumption that wormholes are physical (few cosmologists would agree)

That last assumption just bowled me over and I stopped counting. Wormholes, warp drive, time-travel, where will it end? And all this to save an unphysical assumption (a)!

If there is one lesson we should learn from this mess, it is that God is subtle, but He is orderly and doesn’t play dice.

Rob Sheldon is the author of Genesis: The Long Ascent and The Long Ascent, Volume II.