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If hidden variable theories exist, they're non-local. Which is a whole other philosophical problem. As for many worlds - when everything is possible, nothing i

If hidden variable theories exist, they're non-local. Which is a whole other philosophical problem. As for many worlds - when everything is possible, nothing is explained.

layer8 3y ago
Many-worlds doesn’t mean that everything is possible, it rather means that everything that is possible becomes actual. It is arguably strongest in explanation, in the sense that it relies on the least amount of assumptions (just the Schrödinger equation).
- BoiledCabbage 3y ago
  > It is arguably strongest in explanation, in the sense that it relies on the least amount of assumptions (just the Schrödinger equation). It really seems like Physicists day this because they want it to be true, not because it's actually true. I completely understand they don't like the idea of non-local hidden variables (I mean programmers don't love them much either) - but the idea that a non- local variable is somehow more complex than an infinitely dividing universe breaking into infinite copies and exploring all possible paths at all possible times relies on fewer assumptions or is simpler is just laughable to me. Maybe I'm just not getting it, but it really seems like a way of redefining the rules of a game until the preferred party wins. "Hey we have this compression scheme that's incredibly fast. It's only a constant time lookup." "Really? How do you do that?" "Well we store and index all possible inputs." Won't some outputs be longer due to pigeonhole principle?" "Well actually in one single encoding it would, but we store an infinite number of different encodings of all possible inputs, meaning in at least one of the encodings it's smaller and just use that one." "So you store infinite variations of infinitely sized data and as a result claim your compression scheme is simpler?" "Yes because when we go to decompress we spawn an infinite number of threads and each thread decompresses by following one of the encodings, and in that thread's view it's just a constant time lookup to store the index which is clearly smaller (so compressed) and constant time to reverse and decompress." "And what about the complexity of the infinite threads with infinite copies of infinite storage?" "Ah we don't count that, we only count the world line of the successful thread." The incredible "simplicity" of Many-Worlds.
  - atq2119 3y ago
    I think you're confusing simplicity with computational cost. Bubble sort is simpler than quicksort. It is also more computationally expensive. Universal wave function theory is simple in this sense. (IMHO the term many-worlds is doing the theory a disservice because it's fundamentally misleading. There is only one world, we just can't perceive most of it. Which is as it has been for all of humanity's existence.)
- tsimionescu 3y ago
  The many-worlds interpretation isn't deducible from just the Schrödinger equation. The Schrödinger equation roughly predicts that if you put two detectors at the two possible positions where a light beam can go after a beam splitter, and fire a single photon at the beam splitter, both detectors will detect some "amount" of the photon*. However, what you actually see in experiments is that one of the detectors detects a single photon, and the other detects 0. However, you also notice that if you repeat the experiment many times, the probability of detection is exactly equal to the square of the modulus of the amplitude of the Schrödinger function for that state. To explain this observation, the MWI uses an extra assertion: that each "world" contains a single result, but that the number of "worlds" where the state is X corresponds to the square of the modulus of the amplitude of the Schrödinger function for that state. So, if doing simple frequentist probabilities over these "worlds", your chance as an observer to be in a "world" where the state is X is equal to that value, as the experiments observe. Note that this assumption is exactly the same assumption as the wave function collapse, known as the Born rule. * the Schrödinger equation actually predicts something more esoteric than even that: for any two complementary solutions X and Y, there is an infinity of additional solutions of the form aX + bY, with a and b real numbers with certain properties. So, in fact, it is actually impossible to use the Schrödinger equation to predict any particular state. You have to use the Schrödinger equation and a chosen basis of measurement, and only look at the solutions in that basis. The simple idea of "counting worlds" from above mostly breaks down at this stage - you need an additional third assumption of assuming a pre-existing "background" and using Decoherence to explain why only certain solutions normally manifest.
  - btilly 3y ago
    No, it really is. Consider a sealed room with an experimenter looking at a box with Schrödinger's famous cat in it. The question we usually ask is whether the cat is alive, dead, or in a superposition before the box is opened. Schrödinger's famous equation predicts that if the cat itself can be described by quantum mechanics, then it must be in a superposition. If the experimenter can be described by quantum mechanics as well, then the experimenter must also go into a superposition upon opening the cat's box. And, thanks to thermodynamics, there is no experiment that is doable by the experimenter from which the existence of collapse can be demonstrated. Therefore the claim that there is a collapse at all is an entirely unnecessary hypotheses. All other interpretations of QM have to invent explanations for an event (collapse) that no experimental evidence exists for.
FeepingCreature 3y ago
Fundamental randomness also explains nothing, but worse.

If hidden variable theories exist, they're non-local. Which is a whole other philosophical problem. As for many worlds - when everything is possible, nothing is explained.

layer8 3y ago

Many-worlds doesn’t mean that everything is possible, it rather means that everything that is possible becomes actual. It is arguably strongest in explanation, in the sense that it relies on the least amount of assumptions (just the Schrödinger equation).

BoiledCabbage 3y ago
> It is arguably strongest in explanation, in the sense that it relies on the least amount of assumptions (just the Schrödinger equation). It really seems like Physicists day this because they want it to be true, not because it's actually true. I completely understand they don't like the idea of non-local hidden variables (I mean programmers don't love them much either) - but the idea that a non- local variable is somehow more complex than an infinitely dividing universe breaking into infinite copies and exploring all possible paths at all possible times relies on fewer assumptions or is simpler is just laughable to me. Maybe I'm just not getting it, but it really seems like a way of redefining the rules of a game until the preferred party wins. "Hey we have this compression scheme that's incredibly fast. It's only a constant time lookup." "Really? How do you do that?" "Well we store and index all possible inputs." Won't some outputs be longer due to pigeonhole principle?" "Well actually in one single encoding it would, but we store an infinite number of different encodings of all possible inputs, meaning in at least one of the encodings it's smaller and just use that one." "So you store infinite variations of infinitely sized data and as a result claim your compression scheme is simpler?" "Yes because when we go to decompress we spawn an infinite number of threads and each thread decompresses by following one of the encodings, and in that thread's view it's just a constant time lookup to store the index which is clearly smaller (so compressed) and constant time to reverse and decompress." "And what about the complexity of the infinite threads with infinite copies of infinite storage?" "Ah we don't count that, we only count the world line of the successful thread." The incredible "simplicity" of Many-Worlds.
- atq2119 3y ago
  I think you're confusing simplicity with computational cost. Bubble sort is simpler than quicksort. It is also more computationally expensive. Universal wave function theory is simple in this sense. (IMHO the term many-worlds is doing the theory a disservice because it's fundamentally misleading. There is only one world, we just can't perceive most of it. Which is as it has been for all of humanity's existence.)
tsimionescu 3y ago
The many-worlds interpretation isn't deducible from just the Schrödinger equation. The Schrödinger equation roughly predicts that if you put two detectors at the two possible positions where a light beam can go after a beam splitter, and fire a single photon at the beam splitter, both detectors will detect some "amount" of the photon*. However, what you actually see in experiments is that one of the detectors detects a single photon, and the other detects 0. However, you also notice that if you repeat the experiment many times, the probability of detection is exactly equal to the square of the modulus of the amplitude of the Schrödinger function for that state. To explain this observation, the MWI uses an extra assertion: that each "world" contains a single result, but that the number of "worlds" where the state is X corresponds to the square of the modulus of the amplitude of the Schrödinger function for that state. So, if doing simple frequentist probabilities over these "worlds", your chance as an observer to be in a "world" where the state is X is equal to that value, as the experiments observe. Note that this assumption is exactly the same assumption as the wave function collapse, known as the Born rule. * the Schrödinger equation actually predicts something more esoteric than even that: for any two complementary solutions X and Y, there is an infinity of additional solutions of the form aX + bY, with a and b real numbers with certain properties. So, in fact, it is actually impossible to use the Schrödinger equation to predict any particular state. You have to use the Schrödinger equation and a chosen basis of measurement, and only look at the solutions in that basis. The simple idea of "counting worlds" from above mostly breaks down at this stage - you need an additional third assumption of assuming a pre-existing "background" and using Decoherence to explain why only certain solutions normally manifest.
- btilly 3y ago
  No, it really is. Consider a sealed room with an experimenter looking at a box with Schrödinger's famous cat in it. The question we usually ask is whether the cat is alive, dead, or in a superposition before the box is opened. Schrödinger's famous equation predicts that if the cat itself can be described by quantum mechanics, then it must be in a superposition. If the experimenter can be described by quantum mechanics as well, then the experimenter must also go into a superposition upon opening the cat's box. And, thanks to thermodynamics, there is no experiment that is doable by the experimenter from which the existence of collapse can be demonstrated. Therefore the claim that there is a collapse at all is an entirely unnecessary hypotheses. All other interpretations of QM have to invent explanations for an event (collapse) that no experimental evidence exists for.

FeepingCreature 3y ago

Fundamental randomness also explains nothing, but worse.