Monday, August 26, 2013

Black hole fuzz or fire

Computer complexity theorist Scott Aaronson
Hi from Santa Barbara. I’m at the KITP firewall workshop ...

It’s true that most of the talks have surprisingly little math in them (and, of course, zero input from any recent experiment): it’s mainly just conceptual arguments illustrated by simple cartoons. ...

As I understand it, the issue is actually pretty simple. Do you agree that
(1) the Hawking evaporation process should be unitary, and
(2) the laws of physics should describe the experiences of an infalling observer, not just those of an observer who stays outside the horizon?
If so, then you seem forced to accept ...
How is this even considered science? No experimental evidence and little math -- just cartoons.

I don't see why the laws of physics should tell us about the inside of a black hole. There is no experiment that can tell us anything about what is inside the Schwarzschild radius.

I have argued before (such as here, here, here, and here) that unitarity is a mathematical convenience with no proven physical significance. It is violated by wave function collapse, altho there is no agreement on whether the collapse is real or is an illusion.

Update: A new thesis on wave function collapse has just been posted. It starts with this J.S. Bell quote:
The continuing dispute about quantum measurement theory... is between people who view with di fferent degrees of concern or complacency the following fact: so long as the wave packet reduction is an essential component, and so long as we do not know exactly when and how it takes over from the Schrodinger equation, we do not have an exact and unambiguous formulation of our most fundamental physical theory.
As long as there is this disagreement, there is no agreement that any process is unitary.

1 comment:

  1. I raised a simple few points on Peter Woit's site, only to see he deleted them. I raised the point that General Relativity does not allow for Superposition in highly non linear equations, which are what was used to produce a black hole within an empty unending universe containing NO matter in a asymptotically flat space, that's what happens when you set Ric=0. How are they piling up additional matter in equations which are non linear? Has someone discovered how to solve for two or more masses in Einstein's field equations?
    I would also ask, does dividing by zero produce a 'singularity' as the metric 'blows up'? Apparently Hawkins, Penrose, and a lot of people at UCSB like to think so. I must have missed the memo when division by zero was defined or allowed.

    Stephen Crothers is not very keen on all this magical black hole proliferation either apparently. He makes the claim that 'r' is not a radius of any kind, and has been incorrectly defined in a myriad of incorrect ways by Einstein and his followers, but relates to the inverse square root of the Gaussian curvature.

    Things do not turn from a mathematical 'limiting fiction' into actual physical reality last time I checked, no matter how complicated the math.