All of our math is an attempt to represent things or ideas. The most important thing I learned in my physics education was how to read math as a metaphor for putting together things I understand into a picture of a thing I don't understand. But I don't think anyone serious thinks that their math is "true", such an assertion just makes no sense. The point of it is to find new ways to approach the evidence to see if it gives some different metaphor that wasn't obvious before.
I don't know enough modern physics to have an opinion on whether this is the case for cosmology or string theory, but I do know that in recent history just formulating a problem slightly differently can suddenly make the solution fit in the same framework as a known simpler problem. Not unlike things I read all the time about algorithm research at all, right?
Teaching and understanding models is predicated highly on metaphor, it's much easier to explain for instance that MRI works via a quantum effect that has the same math as a harmonic oscillator than it is to just... dive in. The model isn't the universe, but humans live by metaphor and so the model is important.
Which is perhaps not the point you were trying to make; I don't know enough modern physics to know whether a critique of these new areas as purely fantastical is justified, but it's also pretty fantastical to think of a particle in a box as if it were like a weight on a spring. Who am I to say that something about this approach can't make a currently intractable, approximate, or computational impossible problem solvable with time?
Actually, there's a theorem about that ;) Godel's Incompleteness theorem.
I would describe the problem more like: The new model matches the old model in almost everything (because we've observed a lot). But the math works out quite nicely if itty bitty particles behave this way when exploded at super high temperatures. We have a hard time watching those particles explode, so it's not really tested. Either way it works out, it's not really going to matter for anyone who doesn't explode tiny particles.
I worry that it is the pop sci presentation of physics that non-physicists look at and think wrongly that the actual people carrying out the work are blinded by training bias (which is true for anyone, but I think far less true for experts in the field than otherwise) when in fact it's just the authors of pop sci articles and books who are ignorant of the difference between metaphor and reality. These are people who are paid to figure out how to think differently about their questions, they're not just following conventions and calculating pi to more decimal points.
Is an encryption algorithm "real"? Is the process used in proving a theorem "real"? Is the way that we model an atom "real"? No, of course not; they're all ways to represent an idea/observation through metaphor by breaking down a problem to make it look more like problems we already know how to solve. And if you just decide to approach the metaphor for understanding that idea differently, you can get massively more tractable problems.
As an example, a friend of mine in undergrad was studying crystalline domains in metals and wanted to find a way to understand better the relative misorientations of neighboring crystals in three dimensions. The metaphor as written strongly suggests that the right approach is some manner of statistical approach with a random variable representing orientation that can then be statistically analyzed to provide a misorientation distribution, but the problem is generally intractable in 3 dimensions whereas in 2 dimensions it's fairly straightforward math that way.
He instead decided to represent the crystallites in four or maybe five dimensions, which by so doing he was able to show that the math looks the same as that used for adding angular momentum using Clebsch-Gordon coefficients derived from quantum mechanical spin coupling. And found that by so doing he could turn a statistical problem into one with a closed-form solution that was quicker and easier to calculate in more sophisticated cases. With apologies if I'm explaining it wrong, this one never was quite comprehensible for me, he was far better at math.
Does he then think that crystallite orientation is literally quantum mechanical spin? Of course not. Does the math produce a testably distinguishable result? No, of course not; it should be the same result. But is it likely some future scientist with greater understanding of quantum spin coupling might be able to conceptualize the system more deeply? Definitely! This example is hardly unique.
So my point is that representation and metaphor matters, even if it's not a testably different result. To say that it doesn't matter to me seems to be saying that the current model itself is real, when it's not either! There's no fundamental reason to favor one over the other if the results predicted are the same, other than personal preference, ease of manipulation, or ease of conveying the model/metaphor to future students.
By encouraging different metaphors for the same system, you enable future scientists to be taught those alternative approaches so that they have a bigger toolbox to approaching some yet unknown future problem. We're just humans, and everyone looks at things a bit differently; none of us with a clear picture of what's really "real". Much like how there are a half dozen different approaches for quickly sorting a list, some are more intuitive or powerful or quick to execute than others.
Im not criticizing hard working mathematicians and physicists like your friend- the solution he found sounds rather elegant, and the results are testable. And you are right about having no dogmas when it comes to approaching the riddles of tomorrow- and yet, if all work you do is untestable- you are not a scientist.
In my opinion, physics is and has always been about answering the big questions, the how's, the why's of our existence. That new technology sometimes comes out of it is a bonus, not the ultimate goal.
We are never "done", that's kind of the point I was trying to convey. I completely agree that we should use science to help us deal with our current problems. Once we understand more about our world and ourselves, we will automatically get better at solving them. I'm just against the whole short-term, instant results way of thinking.
The overall point was which I might not have expressed fully is that there is in my opinion too much bias in the field of theoretical physics, and to paraphrase Brian Greene again we took a giant leap and probably skipped a few steps and no one seems to want to look back and see if we missed something.
I think one of my favorite quotes that somewhat describes this view is by Rudolf Peierls: “In recent years the debate on these ideas has reopened, and there are some who question what they call ‘the Copenhagen interpretation’ of quantum mechanics’ - as if there existed more than one possible interpretation of quantum mechanics.”
And I think that this view is antithetical to the advancement of current physics, and sadly this bias is instituted even unintentionally in most new physics students especially those who take physics as part of their degree in CompSci/Engineering.
But I'd also expect that people making new theories be intimately familiar with the current ones, right? It would be silly to expect someone to come up with hamiltonian mechanics for the first time without having ever been exposed to newtonian mechanics, even though both give the same answers to every problem. Yeah, thinking outside the box is always super hard, but you have to at least deeply understand the box before you can know enough to replace it. I definitely don't understand this particular box, but I feel it's reasonable to assume that those that do are trying their darndest to escape it -- if for no other reason than fame if successful.
P.S. If anyone is interested in PWT one of the best materials I've seen is a series of lectures by Mike Towler of Cambridge University[2]. It's probably one of the better constructed lectures I've seen of QM in general, it hits the very rare sweet spot of being actually informative without falling into the realm of popular science while not requiring PHD level physics to follow (infact depending on the country you went to high school if you did cover QM in year 10-12 it's almost everything you need).
[0]https://www.quantamagazine.org/20160517-pilot-wave-theory-ga...
[1]https://en.wikipedia.org/wiki/Von_Neumann%E2%80%93Wigner_int...
[2]http://www.tcm.phy.cam.ac.uk/~mdt26/PWT/lectures/bohm1.pdf (change the url from bohm1 to bohm8 to get all the slides)
Of course, the PWT viewpoint may suggest new ideas and understandings; it is, after all, what led Bell to his inequality and thus spawned all of the entanglement uses including quantum cryptography. But it gets reincorporated into standard quantum mechanics.
None of that really matters. People reject PWT because they want to reject it. There have never been any good reasons. It is an extremely simple theory that answers the questions.
If it gets accepted in the future, it will only be because of a new generation being more willing to embrace it.
At first the physicists said it was impossible and then when it was obvious that it was possible, they said it was too trivial. This is a hallmark of reason being used to justify an already decided on outcome.
It is also not in conflict with string theory. One could imagine string theory actually having strings that evolve. This would be the spirit of PWT applied to that realm.
Yes in it's essence PWT doesn't conflict with the concept of strings (nothing really does), I'm not so sure that I doesn't conflict with the leading "complete" string theories out there today.
But most interpretations have the same statistical predictions as standard QM. The standard Copenhagen setup can be argued to not actually be a theory (the split between quantum and classical in a fundamental theory is an absurdity since the classical is made up of quantum ), but assuming that an interpretation is clear enough to be called a theory and has the same statistical framework as standard quantum mechanics, then experiments will not distinguish them.
The different interpretations, however, may lead to different insights for extending the theory. And in that game, one may pull ahead of the other. For example PWT inspired Bell's results. PWT can also explain the impact of the topology of configuration space convincingly since the configuration is a fundamental part of the theory. It leads to many insights that the others just have to assume.
GRW with a flash ontology has a relativistic version with no foliations. So that's cool.
PS.
To clarify, if double slit will be put in a medium where speed of light is much slower, then there will be a speed, when electron with that speed will stop behaving like wave. This point will be depended on speed of electron, speed of light in medium, and distance between slits.
IMHO, it still possible to adjust slit experiment in such way, that slight increase in speed will break interference, i.e. at speed X electron will behave like wave, but at speed X+1 electron will behave like normal particle.
Why do you describe many-worlds as 'crazy'?
Edit: to whoever down-voted me, this was a serious question.
If you don't really have independent universe forks but something physically continous, what mechanism makes us seem to only observe a single independent branch at all times?
Given the assumption of quantum foam (from the uncertainty principle) at the Planck length + relativity (the Planck length isn't constant like the speed of light, every observer measures it differently relative to others), how many universe branches are really created every picosecond in every Planck length (volume) across the visible universe?
At least, that's what I took away from this:
http://www.askamathematician.com/2010/10/q-copenhagen-or-man...
and this:
http://www.askamathematician.com/2011/11/q-according-to-the-...
Seriously, to my also-completely-laymen mind this seems adding epicycles to me.
But if at every moment you literally have an infinite amount of worlds branching off, then that's vastly bigger than one world in which interactions can be nonlocal. It violates everything from Occam's Razor to practicality.
The question of why time is non reversible can be answered by saying that entropy of a system grows with time, which is a consequence of simple statistics. But with many-worlds you have branching in the forward time direction? Can you explain anything about it?
As I said in my reply to Natanael_L, I was given to understood that the idea of worlds branching off was a misapprehension of the many-worlds interpretation. But I'm prepared to be corrected.
Which is a shame, because John Bell of Bell's theorem was already a fan back in the 60s. He correctly labelled non-locality as the fundamental problem of QM, where other interpretations just let them gloss over this difficulty by labeling such questions "non-physical".
But realistically, I think information-theoretic formalizations of QM will simply gain more popularity in rather than something like de Broglie-Bohm. There's simply too much anti-realism sentiment in the physics community for it to gain much traction.
I'm genuinely curious to know how you think any post Frege philosophy helps. At best philosophy can help prevent research/effort being expended in plausible non-sense; but certainly not in the sense of providing a positive result or foundation for one (which is to my understanding what those doing ST are ultimately seeking).
I'll also take the time here to gripe about post-wittgenstein philosophy which went willy-nilly with formal constructions and basically managed to ignore PI entirely (or otherwise remain mum about it) as well as the his remarks on the foundations of mathematics which set up a lot of problematic for the later.
I don't think philosophy strives to provide positive results. That is left to science. But philosophical ideas can help direct science, and that is a great contribution.
> post Frege philosophy
Post Frege? Even if you only value analytic philosophers, and mostly for their contributions to mathematical logic, I think you should at least acknowledge Russel, Kripke, Putnam and possibly others, if only for their immense contributions to computer science.
This. This is what helps.
> how you think any post Frege philosophy helps
If it doesn't then that explains precisely why we need more new philosophy to make the breakthrough.
Physics can never be about a specific philosophy until it works. Without a working philosophy, we're stuck, which is pretty much where we are right now. We need to keep thinking, and we are, so it's really only a matter of time.
Trudging down those paths prior to experimental evidence is of very real value and is not disconnected from the physics itself.
It's impossible for someone to teach something that they don't know, have never learned, or learned from someone who doesn't really know.
The "good" parts of philosophy are the mushy parts. And when you've created a formal system that's self-consistent yet offers no value, you're going to have to step outside formal systems for a while.
That's gotta be a painful leap for a lot of folks who believe that math is the ultimate reality.
Which is a major problem, given the truism that theory is under-determined by experimental evidence! If given any simple theory of physics I can construct a more complicated theory that makes the same predictions, then we desperately need to confine ourselves to theories that do make unique predictions, lest we be generating ever-more-complicated versions of theories we already had.
For instance, many-worlds is actually conceptually and formally simpler than Copenhagen.
- Two time dimensions [1]
- Reality is actually a discrete, combinatorial graph [2]
- We live in a Euclidean space virtual machine on a
general relativistic virtual machine on a Euclidean actual machine [3]
- Reality is a souped up version of liquid helium,
and of course dark energy is just surface tension [4]
[1]: http://physics.usc.edu/~bars/twoTph.htm [2]: https://en.wikipedia.org/wiki/Loop_quantum_gravity [3]: https://en.wikipedia.org/wiki/Euclidean_quantum_gravity [4]: https://en.wikipedia.org/wiki/Superfluid_vacuum_theory
If the initial work were not peer reviewed, you would not be holding it up as an example of something successful.
Therefore, it's NASA's sponsorship of the peer review which is a necessary and direct cause of you calling it successful here.
So my initial assessment of what you said stands. You're saying the physics community is receptive because NASA sponsored an attempts to verify it. That proves nothing about the receptivity of the physics community nor of even NASA. But I don't expect this to be something you can easily agree with. After all, you're proving my point.
A fairly outlandish invention was developed outside the mainstream physics community. The community saw it and made the effort to test it. This is good, right?
If not, then what should happen?
Which is what exactly?
It's not like they've given it their stamp of approval. Eagleworks is NASA, but as I understand it, they are on a pretty loose leash, and it's their business to investigate somewhat-crackpot ideas.
The main issue is that QFT does not generate a mathematically well-defined evolution of the wave function, but there are promising directions on that front as well: http://arxiv.org/abs/1506.00497
Basically, they treat the Hamiltonian as a whole instead of a perturbation and use a domain for it that has the probabilities flowing from one area to another appropriately to the different particle sectors.
There is also work on dealing with relativity which is a separate issue. While there are solutions, mainly centering on finding a natural foliation, the tension with relativity has not really been resolved, a tension which exists regardless of interpretation.
Exactly, John Bell had it right 50 years ago: non-locality is the problem of QM that needs to be solved, and other interpretations let you simply gloss over the problem without really addressing it. The recent work for finding a natural foliation present in any formalism with a wave function, including Bohmian mechanics, proves every QM shares this problem (or if you think one doesn't, then none of them do for the exact same reasons).
[0]https://en.wikipedia.org/wiki/De_Broglie%E2%80%93Bohm_theory [1]https://en.wikipedia.org/wiki/Pilot_wave
There's a lot of really strange stuff going on with QM and ST, even tho Brian Greene works primarily on ST he did somewhat coined the concept of the "giant leap" that to some extent theoretical physics has run off way too far from anything that can be proven using experimentation.
>Physics has been stuck on this problem for almost a century now. Philosophy won't help.
Philosophy does help, infact it might be the only thing that would help in it's essence philosophy is about how you approach and solve problems, and more importantly how you think about them. It might need be that we do need a major philosophical change in the world of theoretical physics and start thinking about QM and the universe in general in completely different matter.
There is a lot of natural bias that pushes your thinking into a very predictable path and this plagues theoretical physics just like any other field if not more. The bleeding edge of theoretical physics, especially in the past 60-70 years has really shifted towards almost the metaphysical regardless of how much elegant math there is behind it.