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/sci/ - Science & Math

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10757542 No.10757542 [Reply] [Original]

What determines the way the wave function is going to collapse?
That is, what determines the state into which the quantum system is going to decohere?

>> No.10757576

>>10757542
whatever it is, no one ever found any pattern in it.
pure random

>> No.10757578

>>10757542
itself; the system is not closed. the system is an open, unbound set.

>> No.10757806

>>10757576
But is there such a thing as true randomness? It seems to be a way too hocus pocus notion.

>> No.10757808

>>10757806
>It seems to be a way too hocus pocus notion.
Your feelings about physics are irrelevant.

>> No.10757828

>>10757808
Superdeterminism is true, so it's not just a feeling.

>> No.10757845

>>10757806
If anything could possibly be considered evidence for "true randomness," it's QM. We've been performing experiments on quanta for more than 100 years, and the results of measurement are still best described by probability distributions.

Compared with the early to mid 20th century, we can control for just about everything: single atom traps, ultrahigh vacuums with mean free paths of many kilometers, temperatures a few billionths of a degree above 0K, single photon sources, vastly improved materials quality, vastly more sensitive detectors, etc, etc, etc.

Classically, we really should have seen some hint of determinism by now.

>> No.10757872

>>10757845
What holds is not just determinism though. It's superdeterminism.

>> No.10757877

>>10757828
>Superdeterminism is true
No it isnt

>> No.10757878

>>10757877
Prove it.

>> No.10757882

>>10757806
There us no such thing as true randomness, and don’t believe anyone in this shitty thread that tells you there is. True randomness would imply that there would sometimes be “no reason” why a wave function collapsed the way it did. No cause and effect? Good one.

>> No.10757888

>>10757882
This.

>>10757878
>Where are the proofs

It's an axiomatic assumption.

>> No.10757891

>>10757878
Literally all of QM disroves it.
You need to prove superdeterminism, which you can't, because it isn't true and there is no evidence for it.
The universe is stochastic, and via the law of large numbers, the many stochastic probabilities converge to the expected value, which is where the illusion of determinism comes from (but it's really pseudodeterminism). There is no determinism in reality though.
>>10757882
There quite literally is only true randomness. There quite literally is 'no reason' for why the wave function collapsed the way it did.

>> No.10757892

>>10757888
So you base your opinion on axioms? Then why did you say "No, it isnt" instead of something more accurate like "No, i dont think this is how it works"

>> No.10757893

>>10757882
>True randomness would imply that there would sometimes be “no reason” why a wave function collapsed the way it did.
>what is a probability distribution

>> No.10757894

>>10757882
evidence over m-muh feelings

>> No.10757899

>>10757888
>It's an axiomatic assumption.
no, superdeterminism is the axiomatic assumption, because there is no evidence for it whatsoever, its physical explanation requires postulation a giant undetectible infinite field that permeates throughout spacetime to "force" superdeterminism (that doesn't exist and we wouldnt' be able to test for anyway) and all of this is to just deny the actual empirical evidence we have that shows determinism doesn't exist.
IT's the DETERMINISTS who are axiomatically assuming that determinism must be true and then making up psuedoscience to justify it. Nondeterminists are just accepting the reality that the universe is stochastic.

>> No.10757901

>>10757899
>requires postulation a giant undetectible infinite field that permeates throughout spacetime
Its called causality

>> No.10757907

>>10757901
Causality is an axiomatic assumption, and in terms of physics, the way it would physically play out in the universe, it would be a giant "force field" that violates relativity and shoehorns in superdeterminism that we would never be able to test.
i.e. it's nonsense, when there is a much simpler explanation (particles are random, as the amount of particles goes to inifnity the probabilities collapse to their expected value i.e. law of large numbers). It just means reality is nondeterministic which doesn't really matter anyway. There is no reason to cling to determinism or superdeterminism.

>> No.10757925

>>10757893
>what is a probability distribution
A convenient way to dodge the problem. We know the outputs of quantum systems adhere to a probability distribution. We also know that we don't know how that distribution has the values it does. There must be some underlying mechanism that we are unaware or currently unable to measure. But to stop all inquiry at the first steps into the quantum world is bizarre and antiscientific. You cant just declare "We did it guys. God plays dice. Boom. All physics solved." without evidence.

>> No.10757934

>>10757925
More like "whatever does it, it's inside a quantum and measurements are by definition impossible, it's not a limit of technology"

>> No.10757939

>>10757925
>. We also know that we don't know how that distribution has the values it does
Wut. Are you retarded? The whole point of qm is that you can calculate those probability distributions.

>> No.10757948

>>10757907
>would be a giant "force field" that violates relativity
You mean the exact description of all quantum fields? This structure already exists, it is whatever unfolds into the quantum chromodynamical and electroweak fields and assigns the minimal energy (and electrical properties) to the material we call 'vacuum'.
The Standard Model and General and Special relativities all preserve causality. The scientific method (observation based reproducible experiments to confirm or deny hypothesis) only works on a deterministic world. If there WEREN'T a causal relation binding everything in a superdeterministic way no machines would work, no computation would yield consistent results, you'd see 'glitches in reality' (not a single one has ever been observed) and you surely wouldn't be able to respond to this post.

>> No.10757962

>>10757542
https://en.wikipedia.org/wiki/Consistent_histories

>> No.10757974

>>10757934
But that's how humanity always reacts when they believe they have encountered the most fundamental piece of reality. Remember we once thought everything was made of 4 elemental substances, then of cells, then invidisible and incompressible balls called atoms, then came the atomic model, then came fundamental particles, now all the particles are the same entity oscillating at different energy levels (you can take your pick between cosmic strings or fluctuations in the vacuum).
I don't think there's anything 'smaller' than what is studied at the quantum level, but the mathematical description is clearly incomplete.

>>10757939
Which is already useful, yes, and allows us to separate possible from impossible. Unfortunately we can only calculate distributions for trivial interactions between ideal bodies isolated from the rest of Nature and can never have any predictive power (because, again, the formal system of QM is incomplete). Telling me this particular electron has a 50% chance of flipfloping the sign of his spin from t=(now) to t=(heat death of the Universe) doesn't give any useful information.

>> No.10757984

>>10757974
You have no idea what you're talking about. So the predictions of quantum mechanics confirmed routinely by particle colliders are all trivial?

>> No.10757989

>>10757948
Stochastic models can have causality, but determistoc models can't have randomness. None of the things you've written are incompatible with a fundamentally stochastic universe.
There is overwhelming evidence of randomness that you deny in order to hold onto an outdated metaphysics

>> No.10758054

>>10757984
>You have no idea what you're talking about. So the predictions of quantum mechanics confirmed routinely by particle colliders are all trivial?
The predictions made are of ranges of energy, shapes of functions, etc. and they are very good confirmations that QM calculations are going in a good direction. They are not exact mathematical solutions - we can't even fully describe the initial state. And sure, the interaction between a few lead ions and all associated bosons are nightmarishly difficult, but still trivial compared to the full mathematical description of literally any system that is slightly more complex. Imagine the full composite wavefunction describing a macroscopic object. The potential outputs are insane.

>>10757989
I think I understand what you mean: macroscopically, a stochastic universe with convergent behavior would be analogous to a deterministic universe whose behavior is unexplained at fundamental levels. This does make sense to me, and the only way to differentiate between them would be to find the underlying mechanisms of QM - which would be impossible if they didn't exist (stochastic model).
I guess we need a mathematical proof that supports or rejects the existence of underlying mechanisms in QM before asking about determinism.

>> No.10758072

>>10758054
>I guess we need a mathematical proof that supports or rejects the existence of underlying mechanisms in QM before asking about determinism.
Violation of Bell inequalities + Leggett inequalities gets you very very close to rejecting underlying mechanisms. The only plausible mechanisms left are ridiculously contrived.

>> No.10758495

>>10758072
Only local, Bell's theorem does nothing about global hidden variables like Bohmian mechanics.

>> No.10758500

>>10757542
consciousness

>> No.10758525

>>10758495
>global hidden variables
hidden where? 10000 light years away? speed of light anyone?

>> No.10758536

>>10758072
It also leads back to determinism as I was supporting it. The stochastic universe anon may want to have a word.

>>10758500
We do not have a working theory of mind, so it's impossible to attempt to establish a connection between wavefunction collapse (we don't even know whether it happens) and consciousness (extremely ill defined concept). Your reply is simply meaningless.

>> No.10758547

>>10758525
The word 'global' answers all of your silly questions

>> No.10758558

>>10757542
>What determines the way the wave function is going to collapse?
The anthropic principle. :^)

>> No.10758561

>>10757542
Interaction.

>> No.10758568

>>10757845
It's deterministic because it obeys Schrodinger equation, which is unquestionably deterministic.

>> No.10758597

>>10758536
>It also leads back to determinism as I was supporting it.
In no way does it lead back to determinism

>>10758568
The probability distributions evolve deterministically, but the results of measurement drawn from those distributions are random.

>> No.10758631

>>10758597
The results of measurement as all physical processes obey Schrodinger equation, which is deterministic, you brainless nigger.

>> No.10758665

>>10758547
religious bs, just another name for god

>> No.10758688

>>10757891
Holy fucking this.

>> No.10758740

>>10757989
Evidence must be interpreted to make sense. If it's interpreted with a stochastic model, it will give a stochastic picture, a deterministic model will give a deterministic picture. Randomness or determinism are assumed before interpretation by the choice of model.

>> No.10758770

>>10757542
Wave collapse is merely an interpretation. Its not the only interpretation, the alternative is "multiverse" where the entirety of the wave remains. The collapse doesn't happen and the 99.99999999999999999999999999999999_ is does not disappear.

>> No.10758781

And yet we only observe one outcome after measurement. Decoherence can explain how measurement destroys the phase relation between the different possible outcomes, but cannot explain how only one outcome is actually observed.

>> No.10758784

>>10758781
Meant as a reply to >>10758631

>> No.10758792

>>10758784
Decoherence literally means the connection between x/y is forever split and thus whatever happens to y can never be observed by x. Its simply a natural outcome of decoherence.

>> No.10758835

>>10758792
Even after decoherence, x and y both exist unless some random process is introduced to select one or the other. This could be wavefunction collapse, or proposing that our consciousness somehow only exists in one or the other randomly. But some random element is required.

>> No.10758840

>>10758781
In single slit diffraction the slit measures position with precision equal to slit's width and gives you a range of positions - many outcomes.

>> No.10758853

>>10758835
That select doesn't happen. Consciousness is a process in brain, it exists in both if brain works.

>> No.10758861

>>10758853
That's all well and good, but doesn't explain observed reality.

>> No.10759023

Does subjectivity ever arise in hard sciences at all?

>> No.10759053

>>10758861
What do you mean doesn't explain observed reality?

>> No.10759142

>>10759053
It doesn't explain why only a particular outcome is seen. One can't just say that a selection doesn't happen, it clearly does experimentally.

>> No.10759174

>>10759142
What makes you certain that we should see every outcome possible at the same time with decoherence?

>> No.10759211

>>10759174
Each outcome is treated on equal footing by the theory. Nothing in the theory itself makes any possible outcome less real than another, other than some sort of collapse postulate.

>> No.10759256

>>10757882
There's no reason why there's universe at all rather than nothing yet here we are, for no reason. It's not just a stretch to think that at quantum level things might happen "for no reason" as well. Although I too would assume that any seeming randomness is probably due to our ignorance. But the idea of cause and effect being an absolute principle of the universe isn't quite as unproblematic as it may seem.

>> No.10759263

>>10759211
Still doesn't explain why you think we should be able to see every possible outcome with decoherence. Decoherence by definition explains our inability to see every other outcome.

>> No.10759283

>>10758835
>Even after decoherence, x and y both exist unless some random process is introduced to select one or the other. This could be wavefunction collapse, or proposing that our consciousness somehow only exists in one or the other randomly. But some random element is required.

Everettians would say that for every possibility there simultaneously exists another version of you that observes it. You might ask ok, but why do I - this precise version of me, this exact subjective perspective - experience this possibility over another? That would be like asking in general, why do I experience the world from this person's perspective rather than from someone else's? Science at its core ignores that kind of question because no perspective is in scientific terms any more or less real than another.

>> No.10759297

>>10759263
>Decoherence by definition explains our inability to see every other outcome.
The question of key importance is, "other from which one?"

>>10759283
The Everett interpretation postulates that a given observer's path following decoherence is randomly chosen (it may be predetermined in a hidden variable sense, but there is absolutely no way to figure out beforehand which path will be followed.

>> No.10759323

>>10759297
>The Everett interpretation postulates that a given observer's path following decoherence is randomly chosen

It assumes all those paths are equally real and exist simultaneously (so nothing was "chosen" over another). Saying that they are not would be akin to saying that other consciousnesses than your own in general are not real. From subjective point of view you could say that this is equivalent to randomness, but only in the same sense that you randomly just happen to be some random anon on 4chan instead of Donald Trump. Objectively speaking nothing random is going on.

>> No.10759354

>>10759323
That's what I meant by
>it may be predetermined in a hidden variable sense, but there is absolutely no way to figure out beforehand which path will be followed.

>> No.10759838

>>10759283
>You might ask ok, but why do I - this precise version of me, this exact subjective perspective - experience this possibility over another?
Why not?

>> No.10759845

>>10759211
If by "real" you mean "the only state in existence", that not observed in experiments, QM doesn't allow to observe it, because product of orthogonal states is zero, even in stochastic interpretations.

>> No.10759855

>>10759283
Human observes from his exact subjective perspective, because that's how he functions, he doesn't have a function to observe from someone else's perspective.

>> No.10759874

>>10757806
find the pattern then and collect your nobel prize

>> No.10759907

>>10758525
Decoherence is a completely difference beast from the passage of particles. It doesn't create potentially paradoxes like particles do if it's permitted to move faster than light.

>> No.10759912

>>10759907
[citation needed]

>> No.10759913

>>10759912
Citation for what?

>> No.10759917

>>10757576
But pure randomness can't exist in a world governed by deterministic laws. What madness!

>> No.10759920

>>10759917
Einstein was right. God doesn't play with dice. And that's because there is no God.

>> No.10760610

>>10759845
This misses the point though. The states are orthogonal, but after decoherence, the universe is in a superposition of the possible outcomes. The state of the universe is not just one of these, but a superposition of all of them. So why do we see any particular one?

>> No.10760875

>>10759023
Anyone?

>> No.10761045

>>10760610
As opposed to what? We don't see other results because of orthogonality.

>> No.10761095

>>10759917
found the philosopher

>> No.10761123

>>10759917
Yes, it can.

1. Construct perfectly deterministic mathematical world.
2. Simulate it for a billion eons.
3. Reality hackers out of fucking nowhere.
4. Start fucking shit up, challenging the assumptions of the model used to construct the simulation.
5. The physics can't self-correct or infer past states because the entire timeless determinism crystal has become irreversibly entropic.
6. Autistic simulator starts resimulating everything AGAIN in a more isolated region of the void, and posts more robust rules about not griefing sims.
7. Philosophers BTFO.

>> No.10761198

>>10761045
Other than which one? What makes a particular one possibility so special that we see it as a result?

>> No.10761252
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10761252

>>10761123
>3. Reality hackers out of fucking nowhere.

https://youtube.com/watch?v=sGpxO26N5TM

>> No.10761269

>>10761198
It's not special. Because there's nothing special about "you", compared to all the other versions of "you" that observe different results. Just like there's nothing special about your consciousness compared to some totally other guy's consciousness, even though you get to experience only one of them.

>> No.10761540

>>10761269
Taking the Everettian approach is fine, and qualifies as deterministic on the grand scale, but still leaves open the issue of how our own personal experiences can maintain a discrete sense of self, despite the continuum of outcomes for some state variables. I suppose it's up there along with the question of why we perceive time in an evolving fashion.

>> No.10762487

>>10761198
Your result is in your branch, that's how it's special for you. Basically relativity.

>> No.10762497

>>10761540
Even in continuum pure states are orthogonal, they have no trace of each other as if they were isolated from each other and others didn't exist.

>> No.10762516

>>10761540
>discrete sense of self
no one has this

>> No.10762556

>>10757806
*tips fedora*

>> No.10762562

>>10757542
Entropy

>> No.10762667

>>10762516
maybe stop taking so many drugs and you'll be able to tell yourself from a bookcase

>> No.10762674

>>10757542
The brain is an ANTENNA ARRAY.
We don't store memories in the brain, we store spatial and temporal references and upon recollection REMOTE VIEW to access the information.
This is why eg JOSE DELGADO et al found when stimulating parts of the brain, that an individual had a virtually complete recollection of the entirety of the stream of consciousness. It's not merely that we lose the recollection that there's something to recollect and it gets overwritten, it's just been filtered down to reduce the search space.

This is why you can conceive of possibilities but cannot "remember" the future.

>> No.10763037

>>10762497
Unlike discrete eigenstates, these are purely idealized eigenstates which are never truly realized. When analyzing processes like scattering angles, for instance, this results in a sort of continuous blending of "universes" rather than a discrete number of branches.

>> No.10763505

>>10763037
In fact, continuous states work better for MWI (as usual): entanglement describes them perfectly. But collapse can't be really applied here: what the wave function collapses to? To yet uncollapsed uncertainty and doesn't give any certain result? That's not how collapse was supposed to work.