7 ms·

I hope Pilot Wave Theory [0][1] gets more recognition and future work is able to extend it to account for relativity, there's hope that we actually can find a d

by badosu 9y ago

I hope Pilot Wave Theory [0][1] gets more recognition and future work is able to extend it to account for relativity, there's hope that we actually can find a deterministic approach to Quantum Mechanics. Here's a amusing video of an analogous macroscopic experiment, droplets oscillating and interacting with each other at stable states: https://www.youtube.com/watch?v=JUI_DtzXdw4 https://www.youtube.com/watch?v=JUI_DtzXdw4 [0]: https://en.wikipedia.org/wiki/De_Broglie%E2%80%93Bohm_theory https://en.wikipedia.org/wiki/De_Broglie%E2%80%93Bohm_theory [1]: https://en.wikipedia.org/wiki/Pilot_wave https://en.wikipedia.org/wiki/Pilot_wave

DiThi 9y ago
Veritasium video about the topic https://www.youtube.com/watch?v=WIyTZDHuarQ https://www.youtube.com/watch?v=WIyTZDHuarQ
rtpg 9y ago
I've been fairly interested in pilot wave thoery, and the more I delve into it, the less I feel it's useful. My understanding is that the statistical equivalent of the pilot wave theory is "when you flip a coin, there is not a 50/50 chance, but a 100% chance of getting the result, because you got the result". Hyper-determinism. The programming equivalent is "all functions are built with lookup tables, with precomputed values". Great, but I still want to predict the values of the lookup tables to describe the function. From the wiki description of the "guiding function" (basically, the universe's step function): >The main fact to notice is that this velocity field depends on the actual positions of all of the N particles in the universe. This feels totally infalsifiable! "in the exact state of the universe you get the result you get". None of the results end up being usable because there's always the "out" of "the universe has changed". You end up going into hyper-determinism, which is almost all about negating free will. Even if the pilot wave theory is the "real thing", the other model of quantum mechanics ends up being more useful because at least you can make some predictions on the state of the universe. (Would love to have someone explain to me how we can apply Pilot Wave Theory in a "local-ish" fashion, people worked hard on this stuff so I imagine there's some use)
- SomeStupidPoint 9y ago
  ...It makes the same localized predictions as other quantum theories and has the same utility (aside from not having relativity incorporated). One just says "we fundamentally can't know, lulz random" and the other says "we could know, if we knew everything". PWT just has the local probabilistic behavior because we can't know the little fiddly bits of the rest of the universe, even if we know the dominant local forces. Copenhagen just says that it does random shit, no reason. I'm not sure why you think the other interpretation of QM gives predictive power PWT doesn't. Ed: To specifically address the stats point -- PWT says that if we had total knowledge of the universe, we could determine that the coin would always be, eg, heads under specific conditions, but due to measurement limitations we can only say that it will come up 50/50, and that the discrepancy between the theoretical ability to perfectly predict and our need to statistically approximate is related to our ability to measure (and compute). By contrast, Copenhagen says there is no coin between when it leaves your hand and when it lands, so clearly we can't do any better to predict than statistics of how often we see the coin heads on the table after it leaves our hand. You seem to fault PWT for making the same predictions as other models, just because it doesn't declare the problem of doing better fundamentally impossible.
  - rtpg 9y ago
    Isn't PWT saying "well if you saw the entire state of the universe you could know the answer" the physics equivalent of "every terminating calculation is O(1) relative to the heat death of the universe"? Because the interpretation still leads to the "wave function collapse" interpretation in the expermienttal scope anyways, how does it feel less impossible? Is the theory equivalent to other quantum theories? If so, the value of that interpretation is purely philosophical right? Personally I'm not super satisfied. It's brought up as an interpretation that removes the non-determinism, but in reality it hides the non-determinism to the "practically invisible" by extending out to the entire universe. To bring back the stats thing... I could either say I have a 50/50 chance to get heads or tails on a flip, or I could say "well, if I could see through time I'd know all the results and they'd be knowable, so the results are 100% likely to be known". Sure, that's true but that's not happening. Granted, there's no local deterministic theory... but what's the value of determinism if the non-locality extends to the universe?
snarfy 9y ago
Here is another good video on pilot wave theory https://www.youtube.com/watch?v=RlXdsyctD50 https://www.youtube.com/watch?v=RlXdsyctD50
amelius 9y ago
Just wondering, what is the speed of the pilot wave? Is it faster than the speed of light?
- naasking 9y ago
  Yes, it's a non-local theory.

by badosu 9y ago

DiThi 9y ago

Veritasium video about the topic https://www.youtube.com/watch?v=WIyTZDHuarQ https://www.youtube.com/watch?v=WIyTZDHuarQ

rtpg 9y ago

I've been fairly interested in pilot wave thoery, and the more I delve into it, the less I feel it's useful. My understanding is that the statistical equivalent of the pilot wave theory is "when you flip a coin, there is not a 50/50 chance, but a 100% chance of getting the result, because you got the result". Hyper-determinism. The programming equivalent is "all functions are built with lookup tables, with precomputed values". Great, but I still want to predict the values of the lookup tables to describe the function. From the wiki description of the "guiding function" (basically, the universe's step function): >The main fact to notice is that this velocity field depends on the actual positions of all of the N particles in the universe. This feels totally infalsifiable! "in the exact state of the universe you get the result you get". None of the results end up being usable because there's always the "out" of "the universe has changed". You end up going into hyper-determinism, which is almost all about negating free will. Even if the pilot wave theory is the "real thing", the other model of quantum mechanics ends up being more useful because at least you can make some predictions on the state of the universe. (Would love to have someone explain to me how we can apply Pilot Wave Theory in a "local-ish" fashion, people worked hard on this stuff so I imagine there's some use)

SomeStupidPoint 9y ago
...It makes the same localized predictions as other quantum theories and has the same utility (aside from not having relativity incorporated). One just says "we fundamentally can't know, lulz random" and the other says "we could know, if we knew everything". PWT just has the local probabilistic behavior because we can't know the little fiddly bits of the rest of the universe, even if we know the dominant local forces. Copenhagen just says that it does random shit, no reason. I'm not sure why you think the other interpretation of QM gives predictive power PWT doesn't. Ed: To specifically address the stats point -- PWT says that if we had total knowledge of the universe, we could determine that the coin would always be, eg, heads under specific conditions, but due to measurement limitations we can only say that it will come up 50/50, and that the discrepancy between the theoretical ability to perfectly predict and our need to statistically approximate is related to our ability to measure (and compute). By contrast, Copenhagen says there is no coin between when it leaves your hand and when it lands, so clearly we can't do any better to predict than statistics of how often we see the coin heads on the table after it leaves our hand. You seem to fault PWT for making the same predictions as other models, just because it doesn't declare the problem of doing better fundamentally impossible.
- rtpg 9y ago
  Isn't PWT saying "well if you saw the entire state of the universe you could know the answer" the physics equivalent of "every terminating calculation is O(1) relative to the heat death of the universe"? Because the interpretation still leads to the "wave function collapse" interpretation in the expermienttal scope anyways, how does it feel less impossible? Is the theory equivalent to other quantum theories? If so, the value of that interpretation is purely philosophical right? Personally I'm not super satisfied. It's brought up as an interpretation that removes the non-determinism, but in reality it hides the non-determinism to the "practically invisible" by extending out to the entire universe. To bring back the stats thing... I could either say I have a 50/50 chance to get heads or tails on a flip, or I could say "well, if I could see through time I'd know all the results and they'd be knowable, so the results are 100% likely to be known". Sure, that's true but that's not happening. Granted, there's no local deterministic theory... but what's the value of determinism if the non-locality extends to the universe?

snarfy 9y ago

Here is another good video on pilot wave theory https://www.youtube.com/watch?v=RlXdsyctD50 https://www.youtube.com/watch?v=RlXdsyctD50

amelius 9y ago

Just wondering, what is the speed of the pilot wave? Is it faster than the speed of light?

naasking 9y ago
Yes, it's a non-local theory.