4 ms·

I have heard, and like, the theory that 'waveform collapse' due to 'observation' is due to entaglement. Specifically, the idea is that most of the world is quan

by rocqua 2y ago

I have heard, and like, the theory that 'waveform collapse' due to 'observation' is due to entaglement. Specifically, the idea is that most of the world is quantum entangled, 'observation' then has the effect of entangling the observed particle with 'most of the world'. The 'waveform collapse' is then the result of this entaglement with everything causing the waveform to concentrate heavily. Is this concept debunked by this paper, or could it be that 'destroys entanglement' actually means 'becomes entangled with almost everything else'?

deleted 2y ago
[deleted]
rcxdude 2y ago
It's consistent with that interpretation (which is actually the line of reasoning which leads to the many-worlds interpretation). What it shows is that if you take the quantum description of the state of the system, above a certain temperature it turns into a state which can be described as if it were multiple overlapping systems which can be explained purely classically (i.e. no entanglement wierdness). This is what many-worlds is derived from: if you model a quantum system interacting with a big and hot system, you will find that for each outcome of 'collapse', there is a part of the resulting quantum state that corresponds to that observation, and it doesn't interact further with the opposite state. Hence the interpretation that actually the waveform never collapses, it's just the states of the measurement apparatus and the people running it seperate into two states that cease to interact (i.e. many 'parallel universes' inside the same wavefunction: they weren't made up just for fun).
- rocqua 2y ago
  So many-worlds says that the waveform doesn't collapse to a kronecker-delta, but to an average of multiple ones that 'don't interact'. Is this conjecture, do we see this in some specific toy systems, or do we know this is how all 'collapsed' waveforms behave? In other words, to what degree is the many-worlds interpretation just an interpretation of the waveform, or is it also a conjecture about how the waveform behaves? edit: it also sounds like the 'many worlds' are separate, but the 'real' waveform actually still has the information of all the worlds. That suggests the information in that waveform is huge. It also feels like the 'non-collapsed' things from the different worlds could still interact. How much of what I said here is wrong (I presume it is a lot)?
  - rcxdude 2y ago
    It's a bit of both: it's an extrapolation from the results of smaller systems (backed up by experiments like the delayed-choice quantum eraser, which creates an 'observer' which is in a superposition with respect to the experimenter-observer), but it's also reasonably well backed up by theoretical results that large, hot systems will tend to decohere or separate (the result in this paper is interesting because it shows that for this kind of state there's a hard shutoff where quantum effects completely disappear, instead of things just getting less and less 'blurry') And yes, in many ways the conjectured real waveform is quite a beast. Though you could also argue that the information content is actually very low, in that it is fully specified by the boundary condition of the big bang (well, at least any quantum-like correct theory of everything, remember gravity isn't explained by QM). Thus it's any given universe that actually represents a lot of information because it's the result of many different 'decisions' as that initial state starts to become very complex as it evolves (in a similar way to which pi can be simply defined but contains infinite digits, and if it's 'normal', you can find any string of digits in there, but it'll almost certainly take more digits to specify the position of the sequence in pi than are in the sequence). There's often similar objections on the basis of energy/mass which can be addressed in a similar way. And, as far as I understand it the interactions between 'worlds' can only really happen for things that are 'close by', in terms of how much the states have separated (that is, in order to observe quantum effects you need to have isolated the system well enough it hasn't already entangled with you. Once it has you can't undo that). I think one general challenge with conceptualizing it is that in practice the correlations in the waveform are extremely messy: the whole universe is not entangled all at once. The 'splits' suggested in the interpretation are basically creating a potentially infinite amount of universes every time any entanglement occurs, which makes it really hard to reason about (indeed, there are philosophical issues that arise if you try to imagine what you should expect to see as a subjective observer in such a universe)
whatshisface 2y ago
The article doesn't make it clear, but what heat really destroys is, specifically, a type of long-range entanglement between electrons. Heat makes entanglement with containers greater, and entanglement with nearby particles is unavoidable. A very hot cube of metal isolated in a vacuum wouldn't have any less overall entanglement than a cold cube.
- Daneel_ 2y ago
  Missed the opportunity to use a hot spherical cow in a vacuum..
  - nativeit 2y ago
    Mmm. I do love gyros.
EvgeniyZh 2y ago
This paper talks about Gibbs states, i.e., thermal states. These are very specific states that naturally occur if the system is in thermal equilibrium. The other thing you talk about is true. If you have a system in quantum superposition, to measure it you need to entangle it with some macroscopic system. Macroscopic systems decohere very fast. This concept is well explained in excellent John Preskill's quantum computing lecture notes [1] Note that the system for which wavefunction collapses is not in equilibrium with the measurements equipment (otherwise it wouldn't be measured), so the claims of the paper do not apply to this case. [1] https://web.archive.org/web/20231005202201/http://theory.caltech.edu/~preskill/ph219/chap3_15.pdf https://web.archive.org/web/20231005202201/http://theory.cal...
retireddon_tm 2y ago
I feel like there is also a big misconception of 'waveform collapse' and the influence of a cognitive observer 'measuring' the final result, surely wavefunction collapse happens constantly due to several particles self interacting with each other and the environment. (not what your implying btw just needed to state it) and yes quite precisely the destroy entanglement point is the Decoherence process that permanently ties (correlates) that particle with the physical world around it. The future is inherently unknown to any observer and only advancing forward reveals the truth (at least on the Macro scale lol)

by rocqua 2y ago

deleted 2y ago

[deleted]

rcxdude 2y ago

It's consistent with that interpretation (which is actually the line of reasoning which leads to the many-worlds interpretation). What it shows is that if you take the quantum description of the state of the system, above a certain temperature it turns into a state which can be described as if it were multiple overlapping systems which can be explained purely classically (i.e. no entanglement wierdness). This is what many-worlds is derived from: if you model a quantum system interacting with a big and hot system, you will find that for each outcome of 'collapse', there is a part of the resulting quantum state that corresponds to that observation, and it doesn't interact further with the opposite state. Hence the interpretation that actually the waveform never collapses, it's just the states of the measurement apparatus and the people running it seperate into two states that cease to interact (i.e. many 'parallel universes' inside the same wavefunction: they weren't made up just for fun).

rocqua 2y ago
So many-worlds says that the waveform doesn't collapse to a kronecker-delta, but to an average of multiple ones that 'don't interact'. Is this conjecture, do we see this in some specific toy systems, or do we know this is how all 'collapsed' waveforms behave? In other words, to what degree is the many-worlds interpretation just an interpretation of the waveform, or is it also a conjecture about how the waveform behaves? edit: it also sounds like the 'many worlds' are separate, but the 'real' waveform actually still has the information of all the worlds. That suggests the information in that waveform is huge. It also feels like the 'non-collapsed' things from the different worlds could still interact. How much of what I said here is wrong (I presume it is a lot)?
- rcxdude 2y ago
  It's a bit of both: it's an extrapolation from the results of smaller systems (backed up by experiments like the delayed-choice quantum eraser, which creates an 'observer' which is in a superposition with respect to the experimenter-observer), but it's also reasonably well backed up by theoretical results that large, hot systems will tend to decohere or separate (the result in this paper is interesting because it shows that for this kind of state there's a hard shutoff where quantum effects completely disappear, instead of things just getting less and less 'blurry') And yes, in many ways the conjectured real waveform is quite a beast. Though you could also argue that the information content is actually very low, in that it is fully specified by the boundary condition of the big bang (well, at least any quantum-like correct theory of everything, remember gravity isn't explained by QM). Thus it's any given universe that actually represents a lot of information because it's the result of many different 'decisions' as that initial state starts to become very complex as it evolves (in a similar way to which pi can be simply defined but contains infinite digits, and if it's 'normal', you can find any string of digits in there, but it'll almost certainly take more digits to specify the position of the sequence in pi than are in the sequence). There's often similar objections on the basis of energy/mass which can be addressed in a similar way. And, as far as I understand it the interactions between 'worlds' can only really happen for things that are 'close by', in terms of how much the states have separated (that is, in order to observe quantum effects you need to have isolated the system well enough it hasn't already entangled with you. Once it has you can't undo that). I think one general challenge with conceptualizing it is that in practice the correlations in the waveform are extremely messy: the whole universe is not entangled all at once. The 'splits' suggested in the interpretation are basically creating a potentially infinite amount of universes every time any entanglement occurs, which makes it really hard to reason about (indeed, there are philosophical issues that arise if you try to imagine what you should expect to see as a subjective observer in such a universe)

whatshisface 2y ago

The article doesn't make it clear, but what heat really destroys is, specifically, a type of long-range entanglement between electrons. Heat makes entanglement with containers greater, and entanglement with nearby particles is unavoidable. A very hot cube of metal isolated in a vacuum wouldn't have any less overall entanglement than a cold cube.

Daneel_ 2y ago
Missed the opportunity to use a hot spherical cow in a vacuum..
- nativeit 2y ago
  Mmm. I do love gyros.

EvgeniyZh 2y ago

This paper talks about Gibbs states, i.e., thermal states. These are very specific states that naturally occur if the system is in thermal equilibrium. The other thing you talk about is true. If you have a system in quantum superposition, to measure it you need to entangle it with some macroscopic system. Macroscopic systems decohere very fast. This concept is well explained in excellent John Preskill's quantum computing lecture notes [1] Note that the system for which wavefunction collapses is not in equilibrium with the measurements equipment (otherwise it wouldn't be measured), so the claims of the paper do not apply to this case. [1] https://web.archive.org/web/20231005202201/http://theory.caltech.edu/~preskill/ph219/chap3_15.pdf https://web.archive.org/web/20231005202201/http://theory.cal...

retireddon_tm 2y ago

I feel like there is also a big misconception of 'waveform collapse' and the influence of a cognitive observer 'measuring' the final result, surely wavefunction collapse happens constantly due to several particles self interacting with each other and the environment. (not what your implying btw just needed to state it) and yes quite precisely the destroy entanglement point is the Decoherence process that permanently ties (correlates) that particle with the physical world around it. The future is inherently unknown to any observer and only advancing forward reveals the truth (at least on the Macro scale lol)