5 ms·

What hypothesis is being tested here? Is there any theory that predicts that large objects won't behave like waves if they are properly isolated from the enviro

What hypothesis is being tested here? Is there any theory that predicts that large objects won't behave like waves if they are properly isolated from the environment?

deleted 5y ago
[deleted]
deleted 5y ago
[deleted]
tooltower 5y ago
Indeed, there are variations on standard quantum mechanics that postulate that large systems can spontaneously collapse their wave functions. E.g. https://en.wikipedia.org/wiki/Objective-collapse_theory https://en.wikipedia.org/wiki/Objective-collapse_theory Nobody is really expecting large objects to behave differently, but somebody should still check.
- whatshisface 5y ago
  All the large objects are made up of smaller objects...
  - kordlessagain 5y ago
    That’s the current hypothesis, at least.
    - BulgarianIdiot 5y ago
      I pose small things are made of big things, then.
      - miej 5y ago
        this made my morning :)
- prof-dr-ir 5y ago
  It appears that these theories are not relativistic and claim that energy is not conserved. Therefore they will have significant trouble explaining almost all particle physics experiments. From the perspective of a theoretical particle physicist these theories are also awkward because they try to fiddle with non-relativistic quantum mechanics like the Schrodinger equation. But that equation merely arises in the non-relativistic limit of the more fundamental relativistic quantum mechanics, more commonly known as quantum field theory. Therefore, if you want to probe the foundations of quantum theory then quantum field theory seems like a much better place to start. As an analogy, these attempts sound like a nineteenth-century person trying to understand gravity starting from F = m g h rather than F = - G m1 m2 / r^2. For these reasons I would not be supportive of significant funding for theoretical or experimental research in these collapse theories.
  - krastanov 5y ago
    Saying that Schroedinger's equation is a non-relativistic limit is a bit misleading. The typical choice of Hilbert spaces, sure, is non-relativistic. But QFT and any other quantum theory, is basically Schroedinger's equation on a sufficiently weird Hilbert space (from second quantization, graphs, grids, or strings)
    - prof-dr-ir 5y ago
      If you (and the cited wikipedia article a few comments up) mean i d/dt | psi > = H | psi > then sure, that might refer to a relativistic theory and in that sense my comment was imprecise. But showing that a given Hamiltonian is relativistic generally requires work, and I still think there is merit to my point that these theories seem to start 'at the wrong end'.
bawolff 5y ago
I think the big thing is many humans cant wrap their mind around qm. Lots of people are like, its ok as long as it only applies to microscopic quantities but doing a big object would force them to confront reality more head on.
- BulgarianIdiot 5y ago
  > I think the big thing is many humans cant wrap their mind around qm. Especially physicists. As the joke goes, people who think they understand QM, don't. The fact "infinitely many universes spawned infinitely frequently" is a serious take on explaining QM suggests everyone who has a casual explanation about all of this has missed a few things.
andi999 5y ago
One can view it as a falsification experiment to quantum mechanics. Or in other terms to see what the range of applicability is. One doesn't alway know before where new physics is, most likely it is where one hasn't looked experimentally.
- prof-dr-ir 5y ago
  I often see the argument 'we should check because you never know' being used for supporting exotic science experiments. But I think it is too dogmatic. Indeed, we have not tested experimentally whether launching andi999 into space will affect the muon g-2 anomalous magnetic moment. Although you might be very supportive of testing that hypothesis, I would sincerely doubt that it would lead to a discovery of new physics. In the end this boils down to funding decisions for the sciences, which are invariably nuanced, difficult and political. Simply saying 'we should try because nobody else has' would convince only the most naive of funders.
  - andi999 5y ago
    I agree your suggested experiment shdnt be funded. I thought for the other one it is actually quite obvious. You have a quantum realm which has been confirmed by all experiments so far, and you have a classical world (objective trajectories), now it could be that there is a boundary where qm breaks down, or it could be that (when allowing for suitable coherence environments) that this never happens. I think you definitely shd try to push the (experimental) boundary on this one. Same like ppl check if Colombs law is really 1/r^2 (which is an even weaker case where one shd look).
BulgarianIdiot 5y ago
> What hypothesis is being tested here? Is there any theory that predicts that large objects won't behave like waves if they are properly isolated from the environment? We can probably devise some interesting experiments when we have conscious human observers within the apparent independent wave function.
- Chris2048 5y ago
  Are you pushing "quantum conscious" here?
  - BulgarianIdiot 5y ago
    I'm not necessarily pushing for anything, but I'm saying if you have someone who can report what they observe on the other side of this experiment, it'll be a brand new component to extract data from. As for the QM interpretations, honestly all of them are outrageous in their implications, if you truly analyze them. - Copenhagen interpretation can't determine where to draw the line between quantum and classical, and yet says at that line the probability wave collapses. It also has non-local implications, without defining a timespace reference for this non-local effect (i.e. it says things like the wave collapses "everywhere" without describing mechanism for it, and it collapses "now" without noting that "now" has no meaning on universe-wide scale). - Pilot wave and QFT have the same problems as Copenhagen. - Superdeterminism decides cause and effect is just an illusion and everything is determined from initial conditions, but has no explanation for the elaborate cause-effect reality we observe at every moment. - Many worlds requires literally infinite universe clones to spawn at every moment of time. There are few more but they have similar issues.
    - Chris2048 5y ago
      I'm not sure what the relevance of "human observers" is, versus any physical measurement device that can "report" their measurements just as well.
      - BulgarianIdiot 5y ago
m-watson 5y ago
There are plenty of reasons to do this that don't distill just down to do they act as expected. One reason researchers do quantum experiments in macro-objects is it is significantly easier to measure. If they can show the glass bead can be put into quantum states in space it means they can now study quantum states via a glass bead instead of atoms, which are real hard to look at.

What hypothesis is being tested here? Is there any theory that predicts that large objects won't behave like waves if they are properly isolated from the environment?

deleted 5y ago

[deleted]

deleted 5y ago

[deleted]

tooltower 5y ago

Indeed, there are variations on standard quantum mechanics that postulate that large systems can spontaneously collapse their wave functions. E.g. https://en.wikipedia.org/wiki/Objective-collapse_theory https://en.wikipedia.org/wiki/Objective-collapse_theory Nobody is really expecting large objects to behave differently, but somebody should still check.

whatshisface 5y ago
All the large objects are made up of smaller objects...
- kordlessagain 5y ago
  That’s the current hypothesis, at least.
  - BulgarianIdiot 5y ago
    I pose small things are made of big things, then.
    - miej 5y ago
      this made my morning :)
prof-dr-ir 5y ago
It appears that these theories are not relativistic and claim that energy is not conserved. Therefore they will have significant trouble explaining almost all particle physics experiments. From the perspective of a theoretical particle physicist these theories are also awkward because they try to fiddle with non-relativistic quantum mechanics like the Schrodinger equation. But that equation merely arises in the non-relativistic limit of the more fundamental relativistic quantum mechanics, more commonly known as quantum field theory. Therefore, if you want to probe the foundations of quantum theory then quantum field theory seems like a much better place to start. As an analogy, these attempts sound like a nineteenth-century person trying to understand gravity starting from F = m g h rather than F = - G m1 m2 / r^2. For these reasons I would not be supportive of significant funding for theoretical or experimental research in these collapse theories.
- krastanov 5y ago
  Saying that Schroedinger's equation is a non-relativistic limit is a bit misleading. The typical choice of Hilbert spaces, sure, is non-relativistic. But QFT and any other quantum theory, is basically Schroedinger's equation on a sufficiently weird Hilbert space (from second quantization, graphs, grids, or strings)
  - prof-dr-ir 5y ago
    If you (and the cited wikipedia article a few comments up) mean i d/dt | psi > = H | psi > then sure, that might refer to a relativistic theory and in that sense my comment was imprecise. But showing that a given Hamiltonian is relativistic generally requires work, and I still think there is merit to my point that these theories seem to start 'at the wrong end'.

bawolff 5y ago

I think the big thing is many humans cant wrap their mind around qm. Lots of people are like, its ok as long as it only applies to microscopic quantities but doing a big object would force them to confront reality more head on.

BulgarianIdiot 5y ago
> I think the big thing is many humans cant wrap their mind around qm. Especially physicists. As the joke goes, people who think they understand QM, don't. The fact "infinitely many universes spawned infinitely frequently" is a serious take on explaining QM suggests everyone who has a casual explanation about all of this has missed a few things.

andi999 5y ago

One can view it as a falsification experiment to quantum mechanics. Or in other terms to see what the range of applicability is. One doesn't alway know before where new physics is, most likely it is where one hasn't looked experimentally.

prof-dr-ir 5y ago
I often see the argument 'we should check because you never know' being used for supporting exotic science experiments. But I think it is too dogmatic. Indeed, we have not tested experimentally whether launching andi999 into space will affect the muon g-2 anomalous magnetic moment. Although you might be very supportive of testing that hypothesis, I would sincerely doubt that it would lead to a discovery of new physics. In the end this boils down to funding decisions for the sciences, which are invariably nuanced, difficult and political. Simply saying 'we should try because nobody else has' would convince only the most naive of funders.
- andi999 5y ago
  I agree your suggested experiment shdnt be funded. I thought for the other one it is actually quite obvious. You have a quantum realm which has been confirmed by all experiments so far, and you have a classical world (objective trajectories), now it could be that there is a boundary where qm breaks down, or it could be that (when allowing for suitable coherence environments) that this never happens. I think you definitely shd try to push the (experimental) boundary on this one. Same like ppl check if Colombs law is really 1/r^2 (which is an even weaker case where one shd look).

BulgarianIdiot 5y ago

> What hypothesis is being tested here? Is there any theory that predicts that large objects won't behave like waves if they are properly isolated from the environment? We can probably devise some interesting experiments when we have conscious human observers within the apparent independent wave function.

Chris2048 5y ago
Are you pushing "quantum conscious" here?
- BulgarianIdiot 5y ago
  I'm not necessarily pushing for anything, but I'm saying if you have someone who can report what they observe on the other side of this experiment, it'll be a brand new component to extract data from. As for the QM interpretations, honestly all of them are outrageous in their implications, if you truly analyze them. - Copenhagen interpretation can't determine where to draw the line between quantum and classical, and yet says at that line the probability wave collapses. It also has non-local implications, without defining a timespace reference for this non-local effect (i.e. it says things like the wave collapses "everywhere" without describing mechanism for it, and it collapses "now" without noting that "now" has no meaning on universe-wide scale). - Pilot wave and QFT have the same problems as Copenhagen. - Superdeterminism decides cause and effect is just an illusion and everything is determined from initial conditions, but has no explanation for the elaborate cause-effect reality we observe at every moment. - Many worlds requires literally infinite universe clones to spawn at every moment of time. There are few more but they have similar issues.
  - Chris2048 5y ago
    I'm not sure what the relevance of "human observers" is, versus any physical measurement device that can "report" their measurements just as well.
    - BulgarianIdiot 5y ago

m-watson 5y ago

There are plenty of reasons to do this that don't distill just down to do they act as expected. One reason researchers do quantum experiments in macro-objects is it is significantly easier to measure. If they can show the glass bead can be put into quantum states in space it means they can now study quantum states via a glass bead instead of atoms, which are real hard to look at.