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The present phase of stagnation in the foundations of physics is not normal

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Re: The present phase of stagnation in the foundations of physics is not normal

#141

Post by cli »

I suppose this is as an appropriate time as any to ask for advice: I am a multimillionaire from inheritance, and am about to complete my masters in physics. I wish to work on long term theoretical physics problems that do not seem to be possible under the current publish-or-perish academic system. The plan was to complete a PhD, then leave academia, but lately I have been having severe doubts about continuing onto a PhD, partly due to the cruft that comes with academia. Obviously, future employability due to financial reasons is completely irrelevant to me.

I would greatly appreciate any advice.

Re: The present phase of stagnation in the foundations of physics is not normal

#142

Post by pmichaud »

rthomas6 wrote: post #104
tylermw wrote: post #3

Love this comment left on the post by Peter Shor (of Shor's algorithm--the algorithm that kicked off the quantum computing frenzy). I assume it's him and not an imposter. "It's not just that scientists don't want to move their butts, although that's undoubtedly part of it. It's also that they can't. In today's university funding system, you need grants (well, maybe you don't truly need them once you have tenure, but…

I wonder if some rich people could start a form of charity where they just pay a few incredibly brilliant people a good salary to go do whatever research they want for the rest of their lives. Sort of like patronage. Just bypass the whole grant funding cycle and work on whatever you want, because you're a genius and want to study things other people don't like or understand.

Something like this happens, actually. It's often in the clothing of small nonprofits with small teams of people who are brilliant, or who are basically the support department of the 1 or 2 funded geniuses. Question mark on the efficacy.

Re: The present phase of stagnation in the foundations of physics is not normal

#143

Post by kgwgk »

tbabb wrote: post #139
kgwgk wrote: post #136

Earlier quoted context omitted.

> If you do ask, you find that there is no consistent answer! I'm not sure what's the problem. Why do have to "ask" if the answer doesn't really matter? What answer more consistent than "it doesn't really matter" would you like? Anyway (standard) QM is a non-relativistic theory, QFT may be more satisfactory from that point of view. Re: "interference tagging" - what I mean is that first you detect the photons and late…

> Why do have to "ask" if the answer doesn't really matter? You tell me; Copenhagen is the one that says collapse exists. It sounds like maybe we are on the same page that collapse isn't necessary to explain quantum mechanical observations? In that case, we are both Everettians :).

To explain quantum mechanical observations you need "collapse" (i.e. the projection postulate: immediately after a measurement the state of the quantum system is the projection on the corresponding eigenspace of the operator). I don't know what do you gain by saying that it's not "real" and that it's just "as if".

Re: The present phase of stagnation in the foundations of physics is not normal

#144

Post by CydeWeys »

letitgo12345 wrote: post #12

Well considering that we know everything pretty much about most of everyday physics and new physics requires energies that are almost unreachable and billions of dollars in experimental investment and/or years and decades to collect sufficient data, it's not a surprise at all that foundations of physics progress has slowed. I don't think the physics community is to blame here. Just the nature of reality

This isn't true though. They said the same thing over a century ago, yet if you took those people and plopped them into the present they'd be unable to explain such an important everyday technology as GPS, because it requires an understanding of general relativity to work.

We don't know what we don't know. It's very likely that more discoveries will result in obvious changes that are visible in everyday life, like GPS.

My bet is on quantum mechanics. There's a lot there we don't understand or don't know how to make use of quite yet that nevertheless seems likely to have a very obvious effect on everyday life in the centuries to come.

Re: The present phase of stagnation in the foundations of physics is not normal

#145

Post by no_identd »

I wish physicists would dare blame themselves for (insufficiently dis)trusting their statistician, mathematician & philosopher colleagues.

The reason for physics research becoming more wide, limited & shallow instead of more narrow, broad & deep seem to stem from the foundations of mathematics.

See here for the foundations of math itself: https://mathoverflow.net/a/25385

http://math.andrej.com/2016/10/10/five-stages-of-accepting-c...

(If you struggle with comprehending the above, try drawing Venn diagrams of the logical operations involved to gain a geometric understanding of the matter.)

And here for the foundations of probability theory:

https://link.springer.com/chapter/10.1007%2F978-88-470-2107-... Gian-Carlo Rota - Twelve Problems in Probability Theory No One Likes to Bring Up, The Fubini Lectures, 1998 (published 2001)

Two decades old, but the title still rings as true today as it did twenty years ago, unfortunately.

And here, for the obligatory philosophy slap fight abound in statistics:

https://www.quora.com/For-a-non-expert-what-is-the-differenc...

The philosophical solution to which basically boils down to this image macro:

https://i.imgur.com/MPAntbK.jpg

But for which we lack a sufficiently advanced & logically consistent mathematical formalism, both due to people mostly ignoring, out of ignorance [because from where else do you get the action of ignoring!], the philosophical solution, and, more importantly, because we lack a sufficient mathematical formalism for it due to, among other things, the issues with probability theory.

And here, a small shimmer of hope in the foundations of statistics:

http://mysite.science.uottawa.ca/phofstra/Simpson.pdf

There exists another, unrelated to the above presentation, avenue of highly interesting research out of Brazil, but their results haven't yet reached a stage of maturity where people throw together easily understandable powerpoint slides, which I'll neglect mentioning here for now, because I'd consider that bad etiquette.

Personally, I feel partial to blaming all of this on this Euclid translation error, albeit I say that in partial jest:

http://cgm.cs.mcgill.ca/~godfried/teaching/dm-reading-assign...

...which people still fall for, even in 2018, as exemplified in quite a few papers on the foundations of geometry published in recent years.

In closing:

Physicists don't stand the furthest to the right in this xkcd comic, and out of frame, even further to the right from the already left out philosopher, there exists a recursive boxing match between numerous fields of science conveniently left out of the graphic to maintain a sense of strict hierarchy & order in a reality that lacks such hierarchy:

https://xkcd.com/435/

Also, I'd like to point out that the title of that blog post technically represents a statistically testable hypothesis.

Re: The present phase of stagnation in the foundations of physics is not normal

#146

Post by tbabb »

kgwgk wrote: post #143
tbabb wrote: post #139

Earlier quoted context omitted.

> Why do have to "ask" if the answer doesn't really matter? You tell me; Copenhagen is the one that says collapse exists. It sounds like maybe we are on the same page that collapse isn't necessary to explain quantum mechanical observations? In that case, we are both Everettians :).

To explain quantum mechanical observations you need "collapse" (i.e. the projection postulate: immediately after a measurement the state of the quantum system is the projection on the corresponding eigenspace of the operator). I don't know what do you gain by saying that it's not "real" and that it's just "as if".

Because if we say that some of those alpha_i physically go to zero at any point (e.g., "after"), our predictions are wrong, in agreement with the paper. We have to account for the fact that those alpha_i|i> are still nonzero and "existing", and that our projection onto them is only zero for the time being. A different choice in EPR or a quantum eraser experiment may bring our projection onto those states back out of orthogonality-- or maybe not, if we never make those choices. But if we believe we have the physical freedom to manipulate our experiments, we can't get away with saying those extra "universes" (basis states) physically disappear.

In some cases it is a safe approximation to ignore those extra states for the remainder of our experiment/calculations, but with a small change to the experiment we can make that a bad approximation.

Re: The present phase of stagnation in the foundations of physics is not normal

#147

Post by joaorico »

tylermw wrote: post #3

Love this comment left on the post by Peter Shor (of Shor's algorithm--the algorithm that kicked off the quantum computing frenzy). I assume it's him and not an imposter. "It's not just that scientists don't want to move their butts, although that's undoubtedly part of it. It's also that they can't. In today's university funding system, you need grants (well, maybe you don't truly need them once you have tenure, but…

I think John Bell discovered his revolutionary Bell's theorems of quantum mechanics in a similar way.

I can't find it now in a quick search, but I remember reading that he thought every physicist should devote something like 10% of their time thinking about the foundations of physics/quantum mechanics. (What would he do with 100% of his time?)

Re: The present phase of stagnation in the foundations of physics is not normal

#148

Post by muhbags »

walrus1066 wrote: post #82
jsweojtj wrote: post #50

Earlier quoted context omitted.

It does not predict the fine structure constant, that is an input into the model.

Yes, you're right. I was getting it jumbled up with the magnetic moment of the electron, which is predicted by the SM (well, the QED part anyway), to be slightly different to the 'classical' prediction. Experiment measurement of this is accurate to one part per billion, and is consistent with the QED prediction. The electroweak bits of the SM predict the W & Z bosons, along with their masses, which have also been mea…

Correct me if I'm wrong, but the standard model makes no prediction for the masses of any of the fundamental particles. To my knowledge, they are all input parameters. It might put certain bounds on them, but in the end they are all not predicted by the standard model itself.

This is seen as one of the big issues with the standard model, that it does not actually explain a lot of the characteristics of the fundamental particles like their couplings and masses.

Re: The present phase of stagnation in the foundations of physics is not normal

#149

Post by kgwgk »

tbabb wrote: post #146
kgwgk wrote: post #143

Earlier quoted context omitted.

To explain quantum mechanical observations you need "collapse" (i.e. the projection postulate: immediately after a measurement the state of the quantum system is the projection on the corresponding eigenspace of the operator). I don't know what do you gain by saying that it's not "real" and that it's just "as if".

Because if we say that some of those alpha_i physically go to zero at any point (e.g., "after"), our predictions are wrong, in agreement with the paper. We have to account for the fact that those alpha_i|i> are still nonzero and "existing", and that our projection onto them is only zero for the time being . A different choice in EPR or a quantum eraser experiment may bring our projection onto those states back out of…

I am afraid that you have not understood the paper.

a) You do the measurement first on the "screen" side (and project the quantum state of the pair of photons according to the measurement, the "extra universes" disappear). You do then the measurements on the "idler" side (and project again the quantum state according to standard QM).

b) You modify slighly the setup to reverse the order of the measurements. You do the measurement first on the "idler" side (and project the quantum state of the pair of photons according to the measurement, the "extra universes" disappear). You do then the measurements on the "screen" side (and project again the quantum state according to standard QM).

QM predicts that the outcomes in the original experiment (a) and the "reversed" experiment (b) are the same. And those predictions are verified empirically.

Re: The present phase of stagnation in the foundations of physics is not normal

#150

Post by ZenPsycho »

YeGoblynQueenne wrote: post #70
Koshkin wrote: post #51

Earlier quoted context omitted.

> the frame of reference is wrong According to General Relativity, there's no such thing as a "wrong" frame.

I'm sorry, I don't know what General Relativity says, really. I'm not that kind of geek :0 What if I say there are frames of reference that are irrelevant to discovering the process that generates the observations? Edit: Um, guys? I genuinely don't know what general relativity says and I didn't get the comment above. It'd be nice if someone explained.

General relativity holds that the universe has no “center”, either earth or sun. even more surprising, is that unlike newtonian physics, general relativity says the universe doesn’t even have a single “clock”, and what you observe in astrophysics depends on where you observe it from and how fast you are travelling when you observe it. the speed of light is constant, and space and time will bend in order to maintain the observation that light is always a constant speed.

The location, and speed with which you are travelling is what general relativity calls a "frame of reference", and none of them are "correct" or "incorrect", they're just predictors for what observations will be possible from that frame.

then the weirdest part is that one of the consequences is that planetery bodies are large enough for that “speed of light must remain constant” rule to matter in a particular way as to generate a warping of spacetime around them, the geometry of this warp perfectly explaining gravity. or put another way, we stick to the earth because time runs slightly faster at our heads than at our feet.

This youtube video explains it really well:

https://www.youtube.com/watch?v=Xc4xYacTu-E

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