Lost Causes of Theoretical Physics (2003)
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Lost Causes of Theoretical Physics (2003)
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Re: Lost Causes of Theoretical Physics (2003)
#2The many worlds interpretation is just that, and INTERPRETATION, not a predictive theory. The article seems really upset by that, but is it any reason to label it a lost cause? I guess you can’t really study it or preform experiments on it but that shouldn’t be any suprise for any interpretation of quantum mechanics.
I might be missing something here...
Re: Lost Causes of Theoretical Physics (2003)
#3The many worlds interpretation is just that, and INTERPRETATION, not a predictive theory. The article seems really upset by that, but is it any reason to label it a lost cause? I guess you can’t really study it or preform experiments on it but that shouldn’t be any suprise for any interpretation of quantum mechanics. I might be missing something here...
After skimming the whole thing, I was relieved to see that the argument against Many Worlds was the only one I considered invalid. It took the form of "It's not even a testable theory", rather than "it has mathematical deficiencies".
Well, of course, no one's saying it's testable necessarily, but for various aesthetic and intuitive reasons it still seems valid. Just don't expect predictions from it and you'll be fine.
Re: Lost Causes of Theoretical Physics (2003)
#4> Aspect, Dalibrand and Roger (1982)
Aspect, Dalibard and Roger (1982)
Re: Lost Causes of Theoretical Physics (2003)
#5The many worlds interpretation is just that, and INTERPRETATION, not a predictive theory. The article seems really upset by that, but is it any reason to label it a lost cause? I guess you can’t really study it or preform experiments on it but that shouldn’t be any suprise for any interpretation of quantum mechanics. I might be missing something here...
From other sections it seems clear that the author is a devout adherent of The Copenhagen Interpretation, aka objective wavefunction collapse; this is a close relative of the baseline non-Interpretation “Shut Up And Calculate.” People like that are generally utterly unmoved by anything short of a rigorous mathematical formulation, which works for them in QM where “rigorous mathematical formulation” is pretty much all of what matters.
While I respect the adherence to formalism, the notion that our imperfect view of QM (it doesn’t mesh with GTR after all) represents an ontology to hang your hat on is less respectable. Wavefunction collapse seems like a massive cop-out, and it won’t satisfy anyone except the most rigid logical positivist.
Something like MWI is on the other end of the philosophical spectrum, so the hostility is not surprising. At the end of the day though, it comes down to this:
If you want to build something based on QM, you need someone like this guy.
If you want to satisfy your human need for an ontology, he won’t help you.
Re: Lost Causes of Theoretical Physics (2003)
#6> Rigorous Feynman Path Integrals
It depends on how rigorous you want the treatment to be.
The whole machinery of Feynman diagrams is derived from Path Integrals and Wick's Theorem, so they are rigorous, at least as rigorous as standard perturbation theory using operatorial quantum mechanics.
A mathematical physicist won't be amused, though, that's correct. But I wouldn't say that Path Integrals are less rigorous than the average technique used in Theoretical Physics, and particularly in many-body theory.
Re: Lost Causes of Theoretical Physics (2003)
#7The many worlds interpretation is just that, and INTERPRETATION, not a predictive theory. The article seems really upset by that, but is it any reason to label it a lost cause? I guess you can’t really study it or preform experiments on it but that shouldn’t be any suprise for any interpretation of quantum mechanics. I might be missing something here...
His argument is that it's useless as a research topic because you cannot perform experiments about it.
You can still believe it if you like, but its slightly less useful than trying to convince everyone to replace pi with tau..
Re: Lost Causes of Theoretical Physics (2003)
#8> Rigorous Feynman Path Integrals It depends on how rigorous you want the treatment to be. The whole machinery of Feynman diagrams is derived from Path Integrals and Wick's Theorem, so they are rigorous, at least as rigorous as standard perturbation theory using operatorial quantum mechanics. A mathematical physicist won't be amused, though, that's correct. But I wouldn't say that Path Integrals are less rigorous tha…
I think it's incorrect to say that Feynman diagrams are as rigorous as standard perturbation theory. Perturbation theory in QM has a completely rigorous description. It's controlled approximations to known mathematical objects. By contrast, the derivation of perturbation theory in quantum field theory involves applying reasonable well-understood transformations to mathematical objects which are largely _unknown_. Nothing protects you from garbage-in, garbage out. (Perturbation theory turns out perfectly sensible looking answers for theories like 6 dimensional scalar field theory, which doesn't actually exist.)
That said, Feynman integrals are something mathematical physicists have a reasonable level of comfort with these days. There's a well-developed theory of Euclidean path integrals which works just the way Feynman integrals are supposed to. The rigorously constructed examples are lower dimensional field theories, like scalar field theory in 3d, but they don't really differ in kind from the 4d theories used in particle physics. It's just that the analysis gets significantly harder in 4d.
Re: Lost Causes of Theoretical Physics (2003)
#9The many worlds interpretation is just that, and INTERPRETATION, not a predictive theory. The article seems really upset by that, but is it any reason to label it a lost cause? I guess you can’t really study it or preform experiments on it but that shouldn’t be any suprise for any interpretation of quantum mechanics. I might be missing something here...
His argument is that it's useless as a research topic because you cannot perform experiments about it. You can still believe it if you like, but its slightly less useful than trying to convince everyone to replace pi with tau..
I mean, the pi/tau thing is _purely_ aesthetic. That's a big waste of time for sure.
Having a more coherent metaphor for the evolution of quantum systems might help with physical insight, though. If e.g. the universe isn't differentiable across spacetime, we need a better understanding of GR. Many worlds insists it is differentiable (and local), so thinking that way could help integrate the two.
It isn't an important thing, but pi/tau is an unrealistically silly thing to compare it to.
Re: Lost Causes of Theoretical Physics (2003)
#10The many worlds interpretation is just that, and INTERPRETATION, not a predictive theory. The article seems really upset by that, but is it any reason to label it a lost cause? I guess you can’t really study it or preform experiments on it but that shouldn’t be any suprise for any interpretation of quantum mechanics. I might be missing something here...
His argument is that it's useless as a research topic because you cannot perform experiments about it. You can still believe it if you like, but its slightly less useful than trying to convince everyone to replace pi with tau..
QM is a mathematical model. Many worlds is an intuition to understand that model. There is a pedagogical question on if many worlds is a useful mental model to have. There is also a philosophical question of if many worlds better captures the essence of the model relative to Copenhagen.
We can also flip it around. Why should we think of QM in terms of the Copenhagen when it makes to testable predictions.