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[Khaz]

Was really interesting, but Occam's razor tells me my lack of full comprehension and the near-absolute rejection of the pilot wave theory, mean there's probably a lot more to it than just "Oh Heisenberg and those jerks were first, otherwise Pilot Wave would be the primary theory..."

It seems that in both Quantum and Bohmian, particles behave like both a wave and a particle, so any experiment that uses the wave-particle duality can be explained by either. Where they do differ is in explaining how a particle can be described as either a wave or a particle at the same time. Given how we can't extricate this intrication, the only way to say one is more likely is to apply philosophy to it. A bit like explaining protons and neutrons before the LHC: you can have fancy ideas about what's in it, but you can't know until you split one in half (and if you can't, for all we know it's really a single particle not made of other smaller ones). So whether a particle is probabilistic in its position and speed (?), or a tangible particle bouncing on itself deterministically isn't really relevant to do applied physics: both behave in the same way in the experiments and applications we do.

Something though: in the Bohmian "bouncing on its own wave" particle, wouldn't you need a substrate, a medium to bounce on? Or is that explained with Quantum or other physics?

 

[infinitys_7th]

People who deal with logical constructs their whole life don't like spooky things.

Probability is a logical construct. I'm not seeing where it is spooky.

Based on human observation, the universe is driven heavily by mathematical structures. Why is a quantum state being a random variable (which is a well defined structure) more "spooky" than gravitational force falling off by an inverse square law?

It seems reasonable that if we see non-random variables in nature we might also see random variables.

 

[ElFly]

afaik the double slit experiment even works when a single photon is emitted, which I doubt this silicon droplet experiment can duplicate (pun intended)

so this whole theory makes for a p interesting and helpful illustration, but it is not a satisfying replacement for quantum mechanics

e: I may have misread the op...mmm

but I have to wonder what happens if you pop the bubble as it passes the slit (thus 'detecting' it). don't think the wave will suddenly disappear ?

 

[Cosmo Clock 21]

And having done a quick search on Google, I'm glad to see I'm not the only one who thinks particle-wave theory could explain why the Em Drive works.

https://www.youtube.com/watch?v=yJD1Iwy5lUY&feature=youtu.be&t=46

 

[efyu_lemonardo]

The Bohmian interpretation is a non local hidden variable theory, isn't it?

There's nothing technically prohibiting such a theory from describing QM, if I understand correctly (Bell's inequality etc.)

It's also not really that much less "spooky" than the Copenhagen interpretation if you ask me.

 

[Dictator93]

It seems just obstination from people that can't accept the probabilistic aspect of reality.

TImes never change!
Nietzsche - written in 1886, mind you

In einzelnen und seltenen Fällen mag wirklich ein solcher Wille zur Wahrheit, irgend ein ausschweifender und abenteuernder Muth, ein Metaphysiker-Ehrgeiz des verlornen Postens dabei betheiligt sein, der zuletzt eine Handvoll "Gewissheit" immer noch einem ganzen Wagen voll schöner Möglichkeiten vorzieht; es mag sogar puritanische Fanatiker des Gewissens geben, welche lieber noch sich auf ein sicheres Nichts als auf ein ungewisses Etwas sterben legen.

In rare and isolated cases, it may really have happened that such a Will to Truth--a certain extravagant and adventurous pluck, a metaphysician's ambition of the forlorn hope--has participated therein: that which in the end always prefers a handful of "certainty" to a whole cartload of beautiful possibilities; there may even be puritanical fanatics of conscience, who prefer to put their last trust in a sure nothing, rather than in an uncertain something.

 

[StalkerUKCG]

Maybe I'm being a nugget here but why does the double slit test never result in a varied pattern under observation if the pilot wave theory is true.

Surely if it was true the end result would display a varied pattern on the detector which doesn't happen under observation.

 

[twobear]

Was really interesting, but Occam's razor tells me my lack of full comprehension and the near-absolute rejection of the pilot wave theory, mean there's probably a lot more to it than just "Oh Heisenberg and those jerks were first, otherwise Pilot Wave would be the primary theory..."

Not necessarily; the important effect of the Copenhagen interpretation is that it 'closed the book', in a sense, on a period of physics where nobody could even agree on the basic epistemological underpinnings of the new theory. It let them shut up and calculate without getting mired in the basically philosophical arguments about the new theory that had occupied a lot of the 1920s. And once they'd done that and settled the field, they could then move on with extending quantum mechanics (through relativistic QM and then quantum field theory). And that, ultimately, is where most of the interesting stuff was thought--pretty rightly--to lie; with the tantalising new problems of getting relativity and quantum mechanics to play nicely together, not with trying to figure out the possibly intractable philosophical problems at the heart of the theory.

 

[Ether_Snake]

afaik the double slit experiment even works when a single photon is emitted, which I doubt this silicon droplet experiment can duplicate (pun intended)

so this whole theory makes for a p interesting and helpful illustration, but it is not a satisfying replacement for quantum mechanics

e: I may have misread the op...mmm

but I have to wonder what happens if you pop the bubble as it passes the slit (thus 'detecting' it). don't think the wave will suddenly disappear ?

Yes it works with a single droplet, and yes the interference pattern disappears.

 

[Khaz]

Maybe I'm being a nugget here but why does the double slit test never result in a varied pattern under observation if the pilot wave theory is true.

Surely if it was true the end result would display a varied pattern on the detector which doesn't happen under observation.

Observation is said to collapse the wave-form, meaning only the particle shows up, not the wave function any more. I suppose the wave disappear while observed, and resume right after. But because it resumes at or right after the slit, it behaves as if the other slit doesn't exist, as it's effectively "out of range", thus the particle behaving as if it passed a single slit and making the double band pattern.

But it's an explanation that is satisfactory for both Quantum and Bohmian, though. The two differ only in the description of the particle itself: one is a probabilistic cloud of a particle that can pass both slits at once fucking up our concept of space, the other is a punctual particle riding a self-interacting wave fucking up our concept of time. Their behaviour is strictly identical.

 

[Bold One]

I really dont get this experiment...

Do the particles behave differently when they are being observed?

because if they do,


FUCK!!

 

[iamblades]

Not necessarily; the important effect of the Copenhagen interpretation is that it 'closed the book', in a sense, on a period of physics where nobody could even agree on the basic epistemological underpinnings of the new theory. It let them shut up and calculate without getting mired in the basically philosophical arguments about the new theory that had occupied a lot of the 1920s. And once they'd done that and settled the field, they could then move on with extending quantum mechanics (through relativistic QM and then quantum field theory). And that, ultimately, is where most of the interesting stuff was thought--pretty rightly--to lie; with the tantalising new problems of getting relativity and quantum mechanics to play nicely together, not with trying to figure out the possibly intractable philosophical problems at the heart of the theory.

Except that is not true really.

The Copenhagen interpretation hasn't been the most preferred interpretation among physicists at least for a long time. It might be intimidating to the newcomer to QM because of the names attached to that interpretation, but that doesn't really stop people working in the field from saying it's incorrect.

Back in 1998 a poll of leading physicists was published that said that nearly 60% believed the many worlds interpretation, no clue what the numbers are like these days. I'd imagine a bunch of physicists have given up on the debate as a practical matter and moved on to working on quantum field theory, which is where there is actually new work being done these days.

This stuff about how we interpret the math we all accept as correct is largely irrelevant until the interpretations diverge into differently testable theories.

 

[Ether_Snake]

Except that is not true really.

The Copenhagen interpretation hasn't been the most preferred interpretation among physicists at least for a long time. It might be intimidating to the newcomer to QM because of the names attached to that interpretation, but that doesn't really stop people working in the field from saying it's incorrect.

Back in 1998 a poll of leading physicists was published that said that nearly 60% believed the many worlds interpretation, no clue what the numbers are like these days. I'd imagine a bunch of physicists have given up on the debate as a practical matter and moved on to working on quantum field theory, which is where there is actually new work being done these days.

This stuff about how we interpret the math we all accept as correct is largely irrelevant until the interpretations diverge into differently testable theories.

One thing PWT does though, is open the door to the possibility that the future path of a particle can actually be predicted with precision. At the moment, there is no divergence, but since PWT implies things might be moving deterministically, it might be possible to do an experiment where we could predict the outcome where normally it wouldn't be possible with the standard model. With the standard model, the book is closed, with PWT, you could look further to understand better what's happening between the particle-wave interaction, it might even be possible to manipulate it, who knows.

Regardless, there seems to be a difference in applicable QM such as quantum computing, where PWT would make it easier to program for. Remains to be seen.

edit: Is there a physics OT? I have some questions about entanglement, don't want to derail this thread, although I guess there's little risk of that happening.

 

[Foxix Von]

How does this theory explain the delayed choice quantum eraser experiment?

 

[Byakuya769]

Will this help me get through a wormhole to convort with beautiful blue aliens quicker or nah?

 

[Ether_Snake]

How does this theory explain the delayed choice quantum eraser experiment?

I'm only newly familiar with the eraser experiment, but it's not really surprising that it would be explained as well, otherwise Bohmian interpretations of QM would be pretty weak.

Here is wikipedia's:

Bohmian Interpretation of the delayed choice experiment

One of the easiest ways of "making sense" of the delayed-choice paradox is to examine it using Bohmian mechanics.

[...]

In Bohm's quantum mechanics, the particle obeys classical mechanics except that its movement takes place under the additional influence of its quantum potential. A photon or an electron has a definite trajectory and passes through one or the other of the two slits and not both, just as it is in the case of a classical particle. The past is determined and stays what it was up to the moment T1 when the experimental configuration for detecting it as a wave was changed to that of detecting a particle at the arrival time T2. At T1, when the experimental set up was changed, Bohm's quantum potential changes as needed, and the particle moves classically under the new quantum potential till T2 when it is detected as a particle. Thus Bohmian mechanics restores the conventional view of the world and its past. The past is out there as an objective history unalterable retroactively by delayed choice, contrary to the radical view of Wheeler.

The "quantum potential" Q(r,T) is often taken to act instantly. But in fact, the change of the experimental set up at T1 takes a finite time dT. The initial potential. Q(r,T<T1) changes slowly over the time interval dT to become the new quantum potential Q(r,T>T1). The book PVMM referred to above makes the important observation (sec. 6.7.1) that the quantum potential contains information about the boundary conditions defining the system, and hence any change of the experimental set up is immediately recognized by the quantum potential, and determines the dynamics of the Bohmian particle.

Considering that Couder's silicon particle experiment also caused the interference pattern to disappear when interacting with the particle, all of this at a macro and entirely observable state, it's not surprising that it would too in the quantum eraser experiment.




Edit: theorizing here, unrelated to the above; I wonder if the one rule behind everything is "explore all possibilities at any moment, until a conscious observation is made, then take this possibility only". So you would have a non-deterministic present, where the universe must explore all possibilities, but a deterministic past, and when you put both together you can find the path to move forward; the valid path to the future, the next frame.

So the only way to know if a conscious observation will be made in the future is to take into account the determined past and test it against all the possibilities offered by the present, which is really a sum of the past + an uncertainty factor. The "universe" would try each possibility, in a virtual or temporary reality, and when it finds that there was a conscious observation, this virtual or temporary reality becomes the new present frame.

If you assume that the universe's rule is that it only proceeds when there is a conscious observation, then you can have a deterministic universe with an uncertainty component in its definition.

 

[Raticus79]

Interesting stuff. If the upcoming research results support the EMDrive, then anything that helps shed light on how it works could help to improve the design.

 

[ibyea]

One thing PWT does though, is open the door to the possibility that the future path of a particle can actually be predicted with precision. At the moment, there is no divergence, but since PWT implies things might be moving deterministically, it might be possible to do an experiment where we could predict the outcome where normally it wouldn't be possible with the standard model. With the standard model, the book is closed, with PWT, you could look further to understand better what's happening between the particle-wave interaction, it might even be possible to manipulate it, who knows.

Regardless, there seems to be a difference in applicable QM such as quantum computing, where PWT would make it easier to program for. Remains to be seen.

edit: Is there a physics OT? I have some questions about entanglement, don't want to derail this thread, although I guess there's little risk of that happening.

It wouldn't. Because there is no way to differentiate between the two. The uncertainty principle exists whether Coppenhagen or Bohmian.

 

[Cyan]

“New opinions are always suspected, and usually opposed, without any other reason but because they are not already common.” ~ John Locke

I gotta be honest with you. This quote, or similar ones about people laughing at new ideas until they eventually become common knowledge or whatever, are a big red flag that I should take whatever comes next with a huge grain of salt.

I'm not saying this to be rude, but just as a note that if you want people to come in with an open mind, this is not a good way to do it.

 

[Xe4]

I really dont get this experiment...

Do the particles behave differently when they are being observed?

because if they do,


FUCK!!

Yep, that's exactly what the double slit experiment states. Even with two slits, firing a single particle or photon at a time will cause an interference pattern, which means it interferes with itself.

That is until you measure which slit the particle goes through, in which the pattern observed before no longer exists, and is replaced by a pattern of the particle only going through one slit or another.

This is fucking WEIRD, and is one of the many reasons the formulators of quantum mechanics (de Broigile, Einstein, Schrodinger, etc) had such a hard time wrapping their head around it, and in some cases refused to beleive it. It's also why there are so many different QM interpretations, such as the Copenhagen interpretation, pilot Wave interpretation, many world's interpretation, etc.


Here's a good video on it.
https://youtu.be/ZacggH9wB7Y
Quantum mechanics, more than any other area of physics or science is so completely unintuitive it is useless to even try to probe that rely with our view of the world. The best we can do is experiment and theorize, over and over again.

 

[Paganmoon]

This is like an Off-Topic version of Jeff_Rigby...

 

[pillowtalk]

I like that futurama scene with the close horse race.

"And the winner is... number 3 with a quantum finish!"
"No fair! You changed the outcome by measuring it!"

 

[twobear]

Except that is not true really.

The Copenhagen interpretation hasn't been the most preferred interpretation among physicists at least for a long time. It might be intimidating to the newcomer to QM because of the names attached to that interpretation, but that doesn't really stop people working in the field from saying it's incorrect.

Back in 1998 a poll of leading physicists was published that said that nearly 60% believed the many worlds interpretation, no clue what the numbers are like these days. I'd imagine a bunch of physicists have given up on the debate as a practical matter and moved on to working on quantum field theory, which is where there is actually new work being done these days.

This stuff about how we interpret the math we all accept as correct is largely irrelevant until the interpretations diverge into differently testable theories.

I was talking about the historical case as to why Copenhagen was accepted, rather than why nobody believes in pilot wave now, and, as I said, it was largely a case of moving beyond fruitless philosophical discussions to get involved with the interesting stuff like...quantum field theory. It being more a matter of convenience and Copenhagen being the first 'good enough' interpretation, rather than it being the best and only.

 

[joshbob1985]

I really dont get this experiment...

Do the particles behave differently when they are being observed?

because if they do,


FUCK!!

It's not as magic as people try to make it sound. The particle isn't reacting to the presence of consciousness or anything that spooky.

In order to "observe" a particle you have to interact with it in some way, that interaction collapses the wave function.

I think ha.

 

[Ether_Snake]

I was talking about the historical case as to why Copenhagen was accepted, rather than why nobody believes in pilot wave now, and, as I said, it was largely a case of moving beyond fruitless philosophical discussions to get involved with the interesting stuff like...quantum field theory. It being more a matter of convenience and Copenhagen being the first 'good enough' interpretation, rather than it being the best and only.

That's wrong, because you could have easily done the same by making PWT the standard one, so that really isn't an explanation. There were objections raise early on that led to the Copenhagen interpretation becoming the standard one, but those objections were later challenged properly. Had some of those later points been made earlier, PWT could have been the standard model by now. Neither would have hampered research to lead to the same conclusions to which we have come today as far as we know.

 

[ibyea]

That's wrong, because you could have easily done the same by making PWT the standard one, so that really isn't an explanation. There were objections raise early on that led to the Copenhagen interpretation becoming the standard one, but those objections were later challenged properly. Had some of those later points been made earlier, PWT could have been the standard model by now. Neither would have hampered research to lead to the same conclusions to which we have come today as far as we know.

You missed the point. At certain point they had to move to the relativistic version, quantum field theory, and this is something that the pilot wave version would have really sucked at. QM is not even the most fundamental theory of the universe, it is only an approximation. QFT exists as a better theory, and it has lorentz invariance built into it. (I have my fair share of problems with QFT despite outputting the most accurate results in the history of theoretical physics, but that is another argument entirely)

 

[iamblades]

That's wrong, because you could have easily done the same by making PWT the standard one, so that really isn't an explanation. There were objections raise early on that led to the Copenhagen interpretation becoming the standard one, but those objections were later challenged properly. Had some of those later points been made earlier, PWT could have been the standard model by now. Neither would have hampered research to lead to the same conclusions to which we have come today as far as we know.

The reason the Copenhagen interpretation was accepted was because the math works, so the physicists, largely being positivists, mostly said 'good enough, moving on', leaving only those who didn't like the particular spookiness that comes along with what Copenhagen left out to suggest alternate interpretations that shuffle that spookiness to other areas.

From the positivist perspective though, until these interpretations can lead us to meaningfully different predictions, it's all just speculation. Which doesn't mean it's not worth pursuing as an intellectual curiosity, but don't expect to convince anyone that your interpretation is correct.

 

[HTupolev]

Like even though you can't predict when a single particle will decay, they do and in a statistically very predictable way.

That they fall into an easily-described distribution doesn't say anything as to whether or not each sample's position in the distribution is probabilistic.

[edit] apparently, maths says a number cannot be proven to be random. It means that a suite has to be considered random until proven otherwise, null-hypothesis etc. it doesn't say that randomness cannot exist, just that we can push forward eliminating randomness up to... infinity I guess?

That's sort of a different issue, of verifying patterns in statistics.

Things affecting the location of each sample can be deterministic even if you're not getting much in the way of patterns in the output: like if the starting properties of each entity aren't particularly patterned, or if the system is chaotic.

to add to this, Newton's mechanics also fail to accurately describe the very massive (give or take the mass of the sun), where the General theory of relativity is needed to accurately describe gravitational phenomena.

There's not any particular mass scale where it becomes relevant. For instance, the gravity of the Earth is plenty to seriously screw with high-precision timing systems, something that GPS satellites do account for.

If that is the case, doesn't this in a sense debunk quantum computing? Anyone know this scienceGAF?

Not at all. All that matters is that the functional behavior of the computer is the same.

 

[surrogate]

I really dont get this experiment...

Do the particles behave differently when they are being observed?

because if they do,


FUCK!!

Observed in the context of the double slit experiment requires some sort of interaction with the particle passing through the slit.

 

[eot]

Back in 1998 a poll of leading physicists was published that said that nearly 60% believed the many worlds interpretation, no clue what the numbers are like these days. I'd imagine a bunch of physicists have given up on the debate as a practical matter and moved on to working on quantum field theory, which is where there is actually new work being done these days.

Actual new work? There's a shit ton of work being done in QM. Just because it's an old theory doesn't mean that everything about it is understood. Quite the opposite.

 

[Minamu]

As the saying goes: "If you think you understand quantum mechanics, you don't understand quantum mechanics".

If I remember correctly, just placing a detector near the slits won't affect the particles in the experiment, but the wave collapses as you examine the data after the fact? Which makes it even spookier; I think Dr Quantum talked about that?

---

Interesting thread, first time I've ever heard about this competing theory. But I gotta ask OP, why are you so seemingly hell-bent on this theory and wanting to disregard regular QM? It's kinda weird how you keep defending what others are calling a fringe theory (which, if you don't mind me saying, seems reasonable). Discussions are great, but this seems almost personal to you xD

 

[lord pie]

So, if I understand the gist (and I really don't), a particle is traveling on a wave produced by its movement, which it 'rides' to keep moving, but can be redirected by reflections of that same wave - where the wave is bouncing off other nearby particles, hence producing interference?

So for particles that move at the speed of causality like light, then wouldn't the wave either have to be zero at the centre of the particle or move faster than C? So how could it effect itself? Wouldn't that imply the wave would have to be ahead of the particle? (Is that the non local issue?)

Notably the experiment here had the wave propagating out from the particle at significantly higher speed too?

So wouldn't a very simple experiment be to put an occluder *very close* to the path of particles traveling in a straight line? The path should be redirected due to the wave interference produced by the occluder, right? (Or is that predicted by QM for other reasons?)

 

[Ether_Snake]

So, if I understand the gist (and I really don't), a particle is traveling on a wave produced by its movement, which it 'rides' to keep moving, but can be redirected by reflections of that same wave - where the wave is bouncing off other nearby particles, hence producing interference?

So for particles that move at the speed of causality like light, then wouldn't the wave either have to be zero at the centre of the particle or move faster than C? So how could it effect itself? Wouldn't that imply the wave would have to be ahead of the particle? (Is that the non local issue?)

Notably the experiment here had the wave propagating out from the particle at significantly higher speed too?

So wouldn't a very simple experiment be to put an occluder *very close* to the path of particles traveling in a straight line? The path should be redirected due to the wave interference produced by the occluder, right? (Or is that predicted by QM for other reasons?)

Not sure what the answer is regarding the speed of the wave, but your second question; in the experiment that reproduces the double slit one, the particle moves toward the slit, and the wave's interaction with the other waves (such as those from the walls of the slits) causes the particle to change direction. The particles are never quite moving in a straight line though, due to the waves (current one from the particle and others, such as those from past particles).

This is observed at macro scale, and I would assume a computer could reproduce the experiment and even predict the path it would take.

I think an interesting experiment would be to fire a lot of particles, wait, then fire a single one, and see if the amount of particles fired in the past (and the amount of time you wait before firing a single one) can statistically influence the path of future particles. One would assume so as having fired many particles would produce a lot of waves that could influence the path of the single particle shot later. The main variables to play with would just be the quantity of particles fired in the first step, and the waiting period before firing the single one.

What is nice is that you could find the best way to produce the most disturbing wave pattern possible at a macro scale first using fluids, would be based mostly on timing and the do the same with particles to maximize the potential for waves to disturb the single particle.

 

[digdug2k]

I don't have an answer, but I don't see how it would explain it any worst than the Copenhagen-view of QM. Pilot-wave theory gives us the same results as QM does, except it doesn't need far-fetched explanations.

Here a wiki link that sheds some light on what the answer might be: https://en.wikipedia.org/wiki/De_Br...aradox.2C_Bell.27s_theorem.2C_and_nonlocality

I haven't looked at this, but I'm not really sure that particles riding on undetectable "waves" propagating nothing through nothing really provide less of a far-fetched explanation than quantum mechanics. This is all math in the end. If the two sets of equations can be shown to be equivalent, then they're both equally true (or false ). That happened in classical mechanics (and quantum mechanics) frequently. i.e. people come up with two models that describe reality in vastly different ways, but both seem to work. Later someone shows that they're actually both equivalent.

 

[FyreWulff]

I really dont get this experiment...

Do the particles behave differently when they are being observed?

because if they do,


FUCK!!

Yep. Because when you measure something, you're interacting with it.

 

[DpadD]

So... Layman here..

Bohmian says the randomness is due to ignorance of unknown forces...

Doesn't Quantum say the same thing? Isn't CERN and all these Quantum Psyichists trying to figure out what those unknown forces are, learn more about them?

Help me understand the difference here.

 

[Xe4]

So... Layman here..

Bohmian says the randomness is due to ignorance of unknown forces...

Doesn't Quantum say the same thing? Isn't CERN and all these Quantum Psyichists trying to figure out what those unknown forces are, learn more about them?

Help me understand the difference here.

No. Particle physics and quatum physics are not the same thing. They share a lot of similarities, but have vastly different types of reasearch done. Actually, a lot of particle physics uses classical mechanics as a "close enough" approximation, because there are good ways to remeresemt EM, strong and weak force that way.

Quantum mechanics is founded on the principle of randonness. Because particles act like a wave and a particle, some things are impossible to determine. For instance, it's impossible to tell what the spin will be before hand. Every time you look, there will be a 50/50 chance it will be up or down. Also, it is impossible to know both a particles position and momentum at the same time.

It is possible to know the position by superimposing a lot of different waves, but doing so rids you of information of the momentum. Every time people have tried to bring in unknown variables into QM, it had failed by experiment, see the EPR parodox. That's not to say there are no hidden variables, but thus far there is no evidence for them.