Deterministic drivel

>All the mathematics in QM are deterministic
Just wanted to point out that even if the equations are deterministic the system might be chaotic

>the system might be chaotic

But chaotic systems are still deterministic.

Why do people still not understand that something being deterministic does not mean it is predictable?

That is where I disagree. The process of measurement is a key asset of QM.
you can trivially write down an operator for that. That is of course not helping. The concept of measurement only exists due to an abstraction between observer and system, that I agree with. However, if you don't make that distinction the notion of measurement becomes meaningless. So you either are forced to accept measurement as an idealized process or discard it's notion entirely.

So how exactly do you reconcile a non-deterministic worldview with one in which simultaneity is relative?

>all my pretty equations are so deterministic, look!

>yeah the non deterministic aspect is present and obvious in every single experiment but who cares about reality lmao! It's just a detail.

>It's fundamentally deterministic u guize, it just so happens I can't actually do the measurements that would let me show it. Total coincidence.

>I have literally no answer to experimental results inconsistent with psi-epistemic models like arxiv.org/abs/1412.6213

>it's another chaos theory is not deterministic episode
This show has really gone downhill

>arxiv.org/abs/1412.6213

>our results strengthen the view that the entire wavefunction should be real

That's what I've been arguing.

the same way one reconciles a deterministic worldview with one in which the notion of "an outcome" is ill-defined; one doesn't. QM and Relativity don't like each other. The don't get along well at all

What the fuck are you talking about? Relativity is a deterministic theory but the determinism is not derived from lack of simultaneity.

>We find that no knowledge interpretation can fully explain the indistinguishability of non-orthogonal quantum states in three and four dimensions.
Bohmian mechanics is literally a knowledge interpretation.

So you're basically saying any discussion of this is moot until we arrive at some unified theory?

Relativity of simultaneity implies determinism.

Non-determinism means that the 'future' is undecided. However the relativity of simultaneity means two different observers can disagree as to what constitutes past and future. Since the two observers will ALWAYS agree on the overall nature of events, this implies the universe is deterministic as one observers 'present' is another observer's 'future' but both are the same.

When did I claim to be a bohmian?

Nigger do you even know what you're talking about? Bohmian mechanics are nonlocal, you're not solving that problem at all.

>When did I claim to be a bohmian?
Since you are defending knowledge interpretations, while specifically quoting a guy who attacked Bohmian mechanics, I assume you were.
Point applies anyway.

>Relativity of simultaneity implies determinism.
You keep saying this without explaining how. It's because you don't know.

in essence, yes. The main problem is that "a deterministic universe" is a terribly ill-defined term unlike "a deterministic theory". You can try to reconstruct physical models by adding intricate terms which leave the physics practically invariant (Bohmian mech as I have come to understand it) while doing nothing but make words mean things with no physical benefit.
The other option you have is setting a definition half the people won't agree with because theory gives us no reason to consider that definition special. The whole conversation always ends the same way ("well according to my definition...") until a 100% consistent theory which NEEDS a clear definition comes along.

well it implies causality, which is technically not the same thing.

>Since the two observers will ALWAYS agree on the overall nature of events, this implies the universe is deterministic as one observers 'present' is another observer's 'future' but both are the same.
You're being the question. Why do they agree? Because relativity is deterministic. The lack of simultaneity does not cause them to agree. Would Newtonian simultaneity cause then to disagree??? Moron.

It doesn't imply causality, it simply doesn't affect causality.

>the universe isn't deterministic

Oh, OK user. Guess I'll stop using this computer then because it can't work in this random, indeterministic hellhole universe where there are no exploitable physical or mathematical properties worth pursuing. PS: You are only reading this message because it appeared accidentally; the words were assembled completely at random and propagated through a something that definitely isn't a well structured electrical network.

...correct. In fact, in some lectures I had certain core equations from SR have been derived by demanding causality axiomatically.

>You keep saying this without explaining how. It's because you don't know.

>Ignores my paragraph of explanation

Consider a universe in which simultaneity is relative and also non-deterministic. Now you have people who not only disagree on the order of events, but also on the events themselves.

>Simple chaos theory
Chaos theory is 100% deterministic

non-determinism does not imply that. The event needs to be only non-deterministic in 1 reference frame. Even if the transformation required to switch to any other reference frame is deterministic the overall outcome is non-deterministic. Think of it as filming an idealized die roll and showing different people that video in different speeds at different places & times.

You guys are all aware that modern quantum mechanics is completely deterministic, right?

it's a deterministic theory, yes. But that is not the point.

No it's not. SE being deterministic doesn't meant the whole theory is.
Physics is about experiments. You don't get to remove the part that talks about experiments from your theory and still call it a physical theory.

Your paragraph didn't explain anything. It just begged the question by saying that people agree in what events occurred. Lack of simultaneity didn't cause them to agree. Do you actually believe you explained it or are you just bluffing to protect your pride?

>SE being deterministic doesn't meant the whole theory is.
What other part is there?

>You don't get to remove the part that talks about experiments from your theory and still call it a physical theory.
The part about experiments and experiences is still perfectly deterministic.

>What other part is there?
Collapse, or whatever your favourite interpretation has for measurements.

>The part about experiments and experiences is still perfectly deterministic.
Enlighten me on what you consider "modern quantum mechanics" to be.

>Collapse, or whatever your favourite interpretation has for measurements.
I said *modern* quantum mechanics, user. The observed behavior of measurements follow directly from SE, via the predicted phenomenon of macroscopic decoherence.

>Enlighten me on what you consider "modern quantum mechanics" to be.
The one without any nonsense like collapse postulates or anything like it, of course. You can call it "macroscopic decoherence" or "many worlds" if you like, but that's really just a silly name for "quantum mechanics as described by SE and nothing else".

user, decoherence isn't an interpretation. It only removes diagonal terms on the density matrix, it doesn't tell you which one is picked deterministically.

>modern QM is many world, there is no other possible interpretation, I have cracked quantum physics
spotted the fucking lesswrong plebe
At least have some sense of self-awareness for fuck's sake. Like announcing your favoured interpretation straight on instead of presenting it as "modern QM".

Decoherence doesn't favor MWI by the way.

>it doesn't tell you which one is picked deterministically.
Wait, what? Nothing is picked. All parts of the wavefunction actually happen.

>Decoherence doesn't favor MWI by the way.
Decoherence *implies* MWI. SE predicts that decoherence happens to objects the size of a human, which we might call "many worlds". What more is there to be explained?

>presenting it as "modern QM".
Surely taking the predictions of SE completely straight, without trying to excuse them, is "modern QM" in the obvious sense of the word? Trying to deny the implications of QM as stated is quite clearly an obsolete misunderstanding.

>is "modern QM" in the obvious sense of the word?
No it's fucking not, especially since your argument has LITERALLY NOTHING to do with decoherence. It would be exactly the same if you didn't know about decoherence.

Try to read something else than the fucking sequences.

>mfw a MWIfag pretends he has a deterministic quantum mechanic near me
Can you make an actual prediction, as in write shit on a piece of paper and after we do the experiment? No you can't.
>b...but there is another universe with the correct...
Not determinist.

>Can you make an actual prediction, as in write shit on a piece of paper and after we do the experiment? No you can't.
Sure thing! If I flip a quantum coin, the result as predicted by SE is that both possible results happen, in from-then-on disjoint parts of the wavefunction. A version of me that saw heads and a version of me that saw tails both exist independently. This is a perfectly deterministic prediction.

>It would be exactly the same if you didn't know about decoherence.
Of course it would! Our knowing about it doesn't change the physics, after all.

>No it's fucking not
Really?
There is quantum mechanics as described by the SE; and then there's quantum mechanics in which you desperately try to deny the phenomena predicted by SE, by tacking on ridiculous extra postulates for which zero evidence exists. Which version sounds more modern to you?

>This is a perfectly deterministic prediction.
Just so you know in the future, to avoid embarrassment: "prediction" in physics applies exclusively to experimental results. Unless you're a creationist. Or a MWI supporter apparently.

You know what, user? You're quite right. "prediction" is not the right word here. The above is a deterministic description of what reality is doing, but a prediction it is not. Thank you for pointing that out.

With that mistake out of the way:
>Can you make an actual prediction, as in write shit on a piece of paper and after we do the experiment? No you can't.
No, I can't. Quantum mechanics is deterministic, but still fundamentally unpredictable. And yes, that's clearly a consistent combination; it is deterministic and unpredictable because it deterministically does not give entities inside the universe enough information to predict things. Even so, a hypothetical outsider standing outside the universe -- someone who is running the universe as a simulation, say (who knows?) -- could perfectly predict it, because it IS deterministic. (Yes, I am aware the above is an unlikely construction; it is an illustration of what determinism ultimately means, not a serious proposal for what is actually going on.)

>>What other part is there?
>Collapse, or whatever your favourite interpretation has for measurements.
I would answer not collapse but "Born's rule." Collapse, by which I mean the postulate that says what the wavefunction looks like after the measurement, can easily be removed from quantum mechanics. Simply don't invoke the measurement postulates until all experiments are complete and we no longer care to predict the further evolution of the system. This means that instead of predicting the results of experiments, we have to predict the records of experiments. It's not enough to claim to be a complete interpretation, but it's enough to shut up and calculate.

But Born's rule, the part of the measurement postulates that tells you the probabilities of outcomes, cannot be removed. Remove it, and you have no experimental predictions at all; it's just "everything happens." And this is the point where MW fumbles, either by adding significant complexity to the interpretation, or by flat out failing to predict experiments, depending on what school of MW you describe to.

Now that you start seeing it's really all about information you can embrace relational QM.

This is true. Non-determinism is a meme.