Gotten Wrong About Quantum Physics

New interview:

What We've Gotten Wrong About Quantum Physics

Are there unresolved foundational questions in quantum physics? Philosopher Tim Maudlin thinks so, and joins Brian Greene to explore possible answers.

This program is part of the Big Ideas series, supported by the John Templeton Foundation.

I think they are both leading us astray, and here is the crux:

[Greene] if we're thinking about bore and Is the Copenhagen approach even a theory? 11:51 the Copenhagen spirit or school or whatever do you consider what is 11:58 normally described as the Copenhagen approach is it actually a theory?

[Maudlin] no No 12:03 it's certainly not a theory. What I mean by a theory I think what anybody ought to mean by a theory is a 12:11 presentation of fairly high precision. I don't want to say perfectly precise precision because we've never had that 12:17 for reasons we might talk about, but of fairly high precision, about saying 12:23 here's what I think exists in the world. so what is there and here's how I think it behaves so that a dynamics which is 12:30 usually presented now in mathematical physics. you use a mathematical formalism 12:36 to represent what there is, and then in terms of that you write down dynamical equations which could be deterministic 12:43 or not probabilistic. Uh that give you a dynamics I would say a theory has to 12:49 have both of those to a reasonably high precision. And if you don't have that you 12:56 just don't have a theory. You may have a perfectly good kind of recipe. what I 13:02 call in my book a recipe for making some predictions but you don't really have a 13:07 theory right.

Got that? Maudlin says that a theory has to have, at a minimum, a precise mathematical representation of what exists, and dynamical equations for making predictions.

Ordinary Copenhagen quantum mechanics satisfies the second condition but fails the first. As Bohr supposedly said, "there is no quantum world." People disagree about what that is supposed to mean, but I take it to mean that QM fails Maudlin's first criterion for a theory.

This sums up my disagreements with Maudlin. I posted my own definition of a theory, and it emphatically does not include Maudlin's first criterion.

Bohr first got famous with his 1911-18 model of the atom. There is tried to precisely describe what exists in the atom. The model had some successes, and was ultimately supplanted by QM. QM describes properties of atom, but it is not clear that it makes sense to have a precise mathematical model of what exists.

Later on, after 42:00, Maudlin tells about attempts to make QM comply with criterion one. In the jargon of von Neumann, Bohm, and Bell, this meant introducing hidden variables. The problem is that such theories are nonlocal and nonrelativistic. But Maudlin persists, in order to achieve what he thinks a theory should be.

I was always baffled by Maudlin's take on Bell's Theorem. Now I see the problem. He takes it as axiomatic that a theory must have hidden variables.

There is more elaboration on his ontology in this new two-hour lecture: Tim Maudlin - The Great Rift in Physics: Tension Between Relativity and Quantum Theory. Even though he has written a lot of very good explanations about relativity, he does not believe in it:

I think I 1:27:44 my personal belief is you can super luminally signal but if you ask me how do I set it up in the lab now I need a 1:27:51 specific theory ... if we could show super luminal 1:28:06 signaling then relativity is dead everybody agrees right nobody would defend it anymore I'll make one more.

Yes, that would kill the conceptual basis for much of XX century physics. This puts him on the outer fringe of Physics thinking. It is like believing in perpetual motion machines or time travel to the past. Keep that in mind when you listen to his explanations.

Another new podcast has more elaboration: Tim Maudlin: Physics and Epistemology.

[Q] the the real question is how did they get away from that um how did this shut up and 14:47 calculate idea take root because it's it's a 14:52 deviation from the history of physics.

[Maudlin] it's a very extreme deviation 14:58 and if you talk to physics students and they give you that I can pretty much 15:03 guarantee it was beaten into them i mean they didn't go into physics nobody you know young person says "Oh I want to be 15:09 a physics major because I want to shut up and calculate." Right i mean it just made sense right 15:15 um typically you're interested in physics because it seems to be a way of finding out about the world and the 15:23 calculation is very much secondhand to that project. ...

16:45 the so-called Copenhagen school really tried to argue that physics had reached 16:51 the end of a certain kind of comprehensibility that 16:56 that if you were to seek really what you feel like understanding of what's going 17:02 on you're going to fail and so the only way forward was just to use 17:07 math and calculate some stuff. um now it turns out that Bohr was wrong. i mean he 17:14 was certainly wrong in the sense that we we do have the the poor few straggling people like 17:20 Einstein who who rejected all this and said "No we really want to do what 17:25 Newton was doing. we want to do what what Boltzman was doing. we want to do what Maxwell was doing."

He is really complaining about the positivism of the Copenhagen school, and how it focused on observables. It is not a deviation. Newton focused on that gravity did, and not what gravity was. Likewise Boltzman and Maxwell.

Einstein was a mixed bag. He is most famous for his work on special relativity, but he very much tried to avoid what was really going on. Lorentz had a theory that moving electromagnetic fields caused the length contraction by distorting the fields that hold atoms together. Einstein refused to endorse or reject that theory. He stuck to saying that the contraction was a logical consequence of his postulates, but never explains how it works. If you just read what Einstein wrote about relativity, you would conclude that he was a positivist of the "shut up and calculate" variety.

Then quantum mechanics came along, and he complained that it was incomplete for not explaining everything. This made Einstein more of a realist than a positivist, and it marked the end of his contributions to Physics.

Maudlin gives another explanation of his two requirements for a theory at about 1:32:00.

now you have to tell me about it that's fine so what 1:33:19 is the fundamental ontology that is what is it your theory postulates to exist 1:33:26 and second how does it behave. what does it do right normally you specify with 1:33:31 some equation some dynamics. okay um now the the the problem is that what is 1:33:39 taught as quantum theory. if you got a book a standard physics text called 1:33:45 quantum mechanics or quantum theory and you read it carefully and you said yeah but what is really being postulated to 1:33:51 exist here, you wouldn't find an answer in that book. they don't just don't address that question. what they give you 1:33:58 is what I call a predictive recipe.

So quantum mechanics is not a theory; it is a predictive recipe.

To illustrate, he cites the supposed scandal of a Lutheran minister writing a positivist forward to the famous Copernicus book, undermining the realism of heliocentrism. What you think of this goes to the heart of what science is all about.

In my view, QM is one of the most successful theories ever created. It is so useful that it has created trillions of dollars of wealth. If it does not meet some philosopher's definition of a theory, then there is something wrong with his definition, not the theory.

I don't want to dump on these guys anymore in this post. I have enough already. Watch the videos and decide for yourself.

Update: A new philosophy paper criticizes Maudlin for saying that laws of nature are ontologically primitive. This relates to whether an interpretation of a scientific theory is really a different theory.