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Please correct me where I am wrong, I have only studied quantum physics as a hobby. I dislike this description of things existing in two places at once, this i

Please correct me where I am wrong, I have only studied quantum physics as a hobby. I dislike this description of things existing in two places at once, this is because I believe that objects exist in one place, then they move to the next place. The interference pattern only highlights the probability of where the particle will be when it's next observed, or "where it moved to". The object does not interfere with itself, it's the probability wave that is interfering with itself, and the wave is something separate from the object but is related to it. The particle does not exist anywhere between its current position and the next. It does not travel in a "linear" or other way, if at time t it was at position 0 and at time tNext it was at position 1, at time tNext*0.5 you cannot assume it was at position 0.5, or both "position 0.5, slightly higher up" and "position 0.5, slightly lower down" at the same time. In another way, in my mind, the object exists here, then it exists there, but it did not exist at the time between here and there, unless you happened to have observed it. Then of course "there" would be where you have made the observation because you have given it something to interact with. I guess my issue is, at what moment does the article say that it exists in two places at once? Are they inferring this from the fact that there is an interference pattern? To quote: "[1] Every particle or group of particles in the universe is also a wave—even large particles, even bacteria, even human beings, even planets and stars. [2] And waves occupy multiple places in space at once. [3] So any chunk of matter can also occupy two places at once." I guess my problem is with [1] "is also a wave". I think that "there is a wave related to the object" but not "the object IS a wave". Then [3] does not follow.

toxicFork 7y ago
To go further, I have a colleague who says there are actually no particles, only waves interacting with other waves. I am trying to get him to make a proper thesis out of this but he is busy trying to earn money to support his family. If there are any theories about this, please link them in the thread! It sort of resonates with what Richard Feynman has been demonstrating in some of his lectures but I have not been able to find the right keywords to search the internet, or the best way to ask scientists. Problems of hobby scientists...
- xcodevn 7y ago
  It is called Quantum Field Theory.
  - toxicFork 7y ago
    Thanks!
    - Sharlin 7y ago
      And it has been the mainstream quantum theory for decades. Nothing new. But physics doesn't concern itself with what "actually exists", only which models work the best. Whether fields or particles are ontologically more basic is a question as of now relegated to the realm of metaphysics. Some physicists have opinions in one way or another, others just subscribe to the "shut up and calculate" school of thought.
- deepnotderp 7y ago
  QFT, the new ether basically
- williamdclt 7y ago
  That's indeed a layman explanation of the mainstream theory. From what I understand of this theory (not a physicist), particle are not small atomic objects but they're not waves either. Nobody can describe what they are otherwise than by mathematic equations describing their interaction. Some of these equations describe some aspects of reality accurately if you think of particles as objects, some others describe some other aspects of reality well if you think of particles as wave. Doesn't mean that particles are either, they just behave like one or the other depending what you're studying
evanb 7y ago
> the wave is something separate from the object but is related to it. This is a common idea in Bohmian epistemology, but, speaking as a professional physicist, I don't think most physicists would hold this position. The wave is the object, the object is the wave. "Particle/wave duality" or whatever is just bad language for "a quantum mechanical thing" I think the point of saying it "exists at two places at once" is that if the molecule exhibited classical behavior then it either would have gone through slit 1 or slit 2, and you'd see two peaks of probability. Instead, you see an interference experiment, so the molecule went... well, here's where language difficulty comes in. It 'went' through both slits 1 and 2? 'It' went through both slits 1 and 2? Its wavefunction went through both slit 1 and slit 2? Its wavefunction went through both slit 1 and slit 2 without becoming entangled with anything else? However, whatever it did, quantum mechanics is clear about one thing: [something] [moved] THROUGH the screen! That is, because probability current [1] is conserved as a direct result of the Schrödinger equation, it definitely did not happen that the molecule vanished on one side in a puff of smoke and WHAM appeared on the other side. So, the molecule "went through the screen", if what you mean is "at the beginning almost all of the probability was on one side of the screen and smoothly evolved to be mostly on the other". Or, rather, at the beginning you measured the position to be definitively on one side of the screen and it smoothly evolved so that later it hit the target, so that its probability was non-negligible on the other side of the screen. Or, strictly speaking, it went forward through the screen one more time than it backtracked... You're right that the molecule didn't have to take some classically-expected "beautiful" trajectory (straight line, parabola, whatever). In fact it did all sorts of crazy things, coherently. Saying that it was coherent is a shortcut for saying that all those crazy ways' probability amplitudes sum (so that they might interfere), rather than their probabilities directly. "occupy two places at once" is just bad language for what things do quantum mechanically. For example, "occupy" is laden with classical expectations---if a solid metal ball occupies a space, air does not. But that's not how quantum mechanics works. You can have a weird quantum mechanical state like "ball at x and air at y"+"ball at y and air at x". In neither addend of the sum are ball and air at the same place (just as you'd expect classically). But if you look at the sum and decide only to look at the description of the ball and forget about the air you'd decide that the ball "occupies two places at once". Of course rather than "air" you can put "nothing" or "vacuum" or whatever. But it still isn't the case that the ball is taking up twice its volume---it's taking up its full volume, but in two alternative ways? Again, language isn't great here. [1] https://en.wikipedia.org/wiki/Probability_current https://en.wikipedia.org/wiki/Probability_current
Beltiras 7y ago
The problem you are having (I think) is this damned phraseology we have grown accustomed to "in two places at once". That's not the proper way to think about it. Anything and everything can be in a superposition of location and state where the location or state is not determined until forced to by some measurement/interaction. The universe if you will is not determined. It's in a superposition of states and positions to be later determined when acted upon.
- poelzi 7y ago
  You are absolutely right. I personally have adopten the BSM-SG (developed by Dr. Stoyan Sarg) model which puts very strict limits on the superposition concept. No particle is ever at two places at once nor does it jump around. The model is however much much finer in it's structural organization. A neutrino for example is quite a large object from the BSM perspective. When a photon for example pumps the CL space volume occupied by a electron orbit, there is a limited time in which the CL is pumped in a way that the photon is existing as a complete structure anymore, but the electron is not yet pushed to a higher orbit. Chapter 7 in the book goes in very much detail of this. This uncertainty is very limited for is existence in time and very limited which processes can implement such uncertainties. From the BSM perspective, looking at the experimental setup, I can not really see, how this will prove uncertainty.
lisper 7y ago
> I believe that objects exist in one place, then they move to the next place. Bohmian mechanics was made for people like you. https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory
coldtea 7y ago
>I dislike this description of things existing in two places at once, this is because I believe that objects exist in one place, then they move to the next place. The interference pattern only highlights the probability of where the particle will be when it's next observed, or "where it moved to". No, that would just be regular motion -- and QM would be no really different from throwing a cannonball (for example) and running the ballistic equations. Remember the classic quote as a guide: "If you think you understand QM, then you don't understand QM". Even more so if what you think it all is, is a classic quaint motion description. That wouldn't be any mystery, wouldn't explain the two slits experiment results, and wouldn't perplex scientists and have different interpretations for a century. >In another way, in my mind, the object exists here, then it exists there, but it did not exist at the time between here and there, unless you happened to have observed it. Then of course "there" would be where you have made the observation because you have given it something to interact with. That would still not cause interference, of explain the experimental results. It's just like regular solid body motion but with added intermittent existence of the object.
- BoiledCabbage 7y ago
  > No, that would just be regular motion -- and QM would be no really different from throwing a cannonball (for example) and running the ballistic equations. This is not true. Under the DeBroglie-Bohm interpretation of QM an object exists at a single place at a time, what is fuzzy is our knowledge of where it is. And this interpretation holds up to all of the double slit and interference behaviors we expect from QM.
  - coldtea 7y ago
    >This is not true. Under the DeBroglie-Bohm interpretation of QM an object exists at a single place at a time, what is fuzzy is our knowledge of where it is. And this interpretation holds up to all of the double slit and interference behaviors we expect from QM. Under the DeBroglie-Bohm, yes. But the above description (which is also what I criticized in the prior comment): (a) an object exists at a single place at a time, (b) what is fuzzy is our knowledge of where it is Are not enough to get to DeBroglie-Bohm interpretation though -- it misses it's critical element: the pilot wave / guide.

toxicFork 7y ago

To go further, I have a colleague who says there are actually no particles, only waves interacting with other waves. I am trying to get him to make a proper thesis out of this but he is busy trying to earn money to support his family. If there are any theories about this, please link them in the thread! It sort of resonates with what Richard Feynman has been demonstrating in some of his lectures but I have not been able to find the right keywords to search the internet, or the best way to ask scientists. Problems of hobby scientists...

xcodevn 7y ago
It is called Quantum Field Theory.
- toxicFork 7y ago
  Thanks!
  - Sharlin 7y ago
    And it has been the mainstream quantum theory for decades. Nothing new. But physics doesn't concern itself with what "actually exists", only which models work the best. Whether fields or particles are ontologically more basic is a question as of now relegated to the realm of metaphysics. Some physicists have opinions in one way or another, others just subscribe to the "shut up and calculate" school of thought.
deepnotderp 7y ago
QFT, the new ether basically
williamdclt 7y ago
That's indeed a layman explanation of the mainstream theory. From what I understand of this theory (not a physicist), particle are not small atomic objects but they're not waves either. Nobody can describe what they are otherwise than by mathematic equations describing their interaction. Some of these equations describe some aspects of reality accurately if you think of particles as objects, some others describe some other aspects of reality well if you think of particles as wave. Doesn't mean that particles are either, they just behave like one or the other depending what you're studying

evanb 7y ago

> the wave is something separate from the object but is related to it. This is a common idea in Bohmian epistemology, but, speaking as a professional physicist, I don't think most physicists would hold this position. The wave is the object, the object is the wave. "Particle/wave duality" or whatever is just bad language for "a quantum mechanical thing" I think the point of saying it "exists at two places at once" is that if the molecule exhibited classical behavior then it either would have gone through slit 1 or slit 2, and you'd see two peaks of probability. Instead, you see an interference experiment, so the molecule went... well, here's where language difficulty comes in. It 'went' through both slits 1 and 2? 'It' went through both slits 1 and 2? Its wavefunction went through both slit 1 and slit 2? Its wavefunction went through both slit 1 and slit 2 without becoming entangled with anything else? However, whatever it did, quantum mechanics is clear about one thing: [something] [moved] THROUGH the screen! That is, because probability current [1] is conserved as a direct result of the Schrödinger equation, it definitely did not happen that the molecule vanished on one side in a puff of smoke and WHAM appeared on the other side. So, the molecule "went through the screen", if what you mean is "at the beginning almost all of the probability was on one side of the screen and smoothly evolved to be mostly on the other". Or, rather, at the beginning you measured the position to be definitively on one side of the screen and it smoothly evolved so that later it hit the target, so that its probability was non-negligible on the other side of the screen. Or, strictly speaking, it went forward through the screen one more time than it backtracked... You're right that the molecule didn't have to take some classically-expected "beautiful" trajectory (straight line, parabola, whatever). In fact it did all sorts of crazy things, coherently. Saying that it was coherent is a shortcut for saying that all those crazy ways' probability amplitudes sum (so that they might interfere), rather than their probabilities directly. "occupy two places at once" is just bad language for what things do quantum mechanically. For example, "occupy" is laden with classical expectations---if a solid metal ball occupies a space, air does not. But that's not how quantum mechanics works. You can have a weird quantum mechanical state like "ball at x and air at y"+"ball at y and air at x". In neither addend of the sum are ball and air at the same place (just as you'd expect classically). But if you look at the sum and decide only to look at the description of the ball and forget about the air you'd decide that the ball "occupies two places at once". Of course rather than "air" you can put "nothing" or "vacuum" or whatever. But it still isn't the case that the ball is taking up twice its volume---it's taking up its full volume, but in two alternative ways? Again, language isn't great here. [1] https://en.wikipedia.org/wiki/Probability_current https://en.wikipedia.org/wiki/Probability_current

Beltiras 7y ago

The problem you are having (I think) is this damned phraseology we have grown accustomed to "in two places at once". That's not the proper way to think about it. Anything and everything can be in a superposition of location and state where the location or state is not determined until forced to by some measurement/interaction. The universe if you will is not determined. It's in a superposition of states and positions to be later determined when acted upon.

poelzi 7y ago
You are absolutely right. I personally have adopten the BSM-SG (developed by Dr. Stoyan Sarg) model which puts very strict limits on the superposition concept. No particle is ever at two places at once nor does it jump around. The model is however much much finer in it's structural organization. A neutrino for example is quite a large object from the BSM perspective. When a photon for example pumps the CL space volume occupied by a electron orbit, there is a limited time in which the CL is pumped in a way that the photon is existing as a complete structure anymore, but the electron is not yet pushed to a higher orbit. Chapter 7 in the book goes in very much detail of this. This uncertainty is very limited for is existence in time and very limited which processes can implement such uncertainties. From the BSM perspective, looking at the experimental setup, I can not really see, how this will prove uncertainty.

lisper 7y ago

> I believe that objects exist in one place, then they move to the next place. Bohmian mechanics was made for people like you. https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory

coldtea 7y ago

>I dislike this description of things existing in two places at once, this is because I believe that objects exist in one place, then they move to the next place. The interference pattern only highlights the probability of where the particle will be when it's next observed, or "where it moved to". No, that would just be regular motion -- and QM would be no really different from throwing a cannonball (for example) and running the ballistic equations. Remember the classic quote as a guide: "If you think you understand QM, then you don't understand QM". Even more so if what you think it all is, is a classic quaint motion description. That wouldn't be any mystery, wouldn't explain the two slits experiment results, and wouldn't perplex scientists and have different interpretations for a century. >In another way, in my mind, the object exists here, then it exists there, but it did not exist at the time between here and there, unless you happened to have observed it. Then of course "there" would be where you have made the observation because you have given it something to interact with. That would still not cause interference, of explain the experimental results. It's just like regular solid body motion but with added intermittent existence of the object.

BoiledCabbage 7y ago
> No, that would just be regular motion -- and QM would be no really different from throwing a cannonball (for example) and running the ballistic equations. This is not true. Under the DeBroglie-Bohm interpretation of QM an object exists at a single place at a time, what is fuzzy is our knowledge of where it is. And this interpretation holds up to all of the double slit and interference behaviors we expect from QM.
- coldtea 7y ago
  >This is not true. Under the DeBroglie-Bohm interpretation of QM an object exists at a single place at a time, what is fuzzy is our knowledge of where it is. And this interpretation holds up to all of the double slit and interference behaviors we expect from QM. Under the DeBroglie-Bohm, yes. But the above description (which is also what I criticized in the prior comment): (a) an object exists at a single place at a time, (b) what is fuzzy is our knowledge of where it is Are not enough to get to DeBroglie-Bohm interpretation though -- it misses it's critical element: the pilot wave / guide.