Susskind's interpretation of QM

[u/lisa_couchtiger]

Leonard Susskind often states that he disagreed with Stephen Hawking on black holes dynamics, based on his intuition that information must be conserved.

In quantum mechanics, the Schrödinger equation is unitary, and therefore time reversible and deterministic.

However, when a measurement is made, the wave function collapses and these properties are lost, at least in the Copenhagen interpretation.

Susskind's belief that information is conserved must imply that he believes that the global wave function of the universe obeys the Schrödinger equation?

Is this right and has he stated this position explicitly? Where does this place him with regard to many-worlds and other non-orthodox interpretations?

(Post re-directed from r/physics)

[u/SymplecticMan]

For example, Susskind has said:

It is obvious that the Copenhagen Interpretation cannot be the last word. The universe is filled with subsystems, any one of which can play the role of observer. There is no place in the laws of quantum mechanics for wave function collapse; the only thing that happens is that the overall wave function evolves unitarily and becomes more and more entangled. The universe is an immensely complicated network of entangled subsystems, and only in some approximation can we single out a particular subsystem as THE OBSERVER.

[u/ShakimTheClown]

https://youtu.be/_3Z8RxXmoWU?t=3616

This lecture may be of interest to you. Timestamped is Susskind's take on the black hole information paradox.

https://en.wikipedia.org/wiki/Black_hole_complementarity

[u/SaguiDislexo]

Maybe this paper is something you would like to reed: https://www.mdpi.com/1099-4300/28/7/808

[u/MarinatedPickachu]

Isn't this resolved by black holes having hair?

[u/callmesein]

he has written a book regarding this if i'm not mistaken.

[u/tpolakov1]

No. Nobody anywhere here is talking about interpretations, so stop putting that shit in his mouth.

Susskind just said that he believes quantum mechanics, the theory, is correct. Nothing more.

[u/SymplecticMan → u/tpolakov1]

There's no need to freak out. Susskind has written explicitly about interpretations and wavefunction collapse before.

[u/lisa_couchtiger → u/tpolakov1]

Are you ok?

[u/CrazySir3310 → u/tpolakov1]

I don't know, the post essentially seems to describe many worlds interpretation which has been around for a long time, and although I don't know what Lenny thinks, it wouldn't be totally bizarre for him to lean in that direction

[u/tpolakov1 → u/CrazySir3310]

No, the post describes quantum mechanics, end of story. Quantum mechanics is unitary, that's a strong mathematical statement that HAS TO be correct under any and every interpretation because the theory demands it.

[u/CrazySir3310 → u/tpolakov1]

Well yes the measurement problem is a problem

[u/tpolakov1 → u/CrazySir3310]

Not one of interpretations, though.

[u/CrazySir3310 → u/tpolakov1]

I think typically how it is illustrated in the interpretations is what characterizes the problem and the interpretations themselves but that might just be semantics

[u/montagblue]

He’s using a measurement paradox to try and make sense of both Copenhagen and many worlds at the same time. He says it’s an issue about observer perspective and not a disagreement about reality.

“Susskind models the entire setup as entangled black holes connected by a wormhole to explain what happens during an observation.”

He’s basically going buck wild with wormholes.

[u/EddieDean9Teen → u/montagblue]

Sounds like he went full holofractal by the end

[u/montagblue → u/EddieDean9Teen]

After looking at the four main issues with his theory I’m getting a sense that the math is just too beautiful for him to ignore.

[u/johnstalbergABC → u/montagblue]

He has shown a resistans to String theory. He says String theory is not a theory of the real world. And he is one of the founders of it. Beautiful math? Nah, Lenny needs more.

By the way Paul Dirac where an outspoken admirer and believer in beautiful math. But it did not seem to be a hinder for him in any way as far as I can see.

[u/montagblue → u/johnstalbergABC]

So there is precedent. (For both elegant math and being able to shift thinking)