Good physics

khaled

What 'matter'? That's the problem! What is measured appears as waves or as particles. But, you're saying, behind what is measured there is 'the matter that already exists'. But that is the point at issue! What is being measured? We can't say what is 'behind' the measurement. One set-up produces a wave pattern, the other a particle pattern. Is it really waves or is it really particles? You can't say! That's the paradox, the whole issue in a nutshell. — Wayfarer

No I’m not. That’s the anti realist view. I’m critiquing it not agreeing with it. Read the quote in context.

We can't say that they are attributes of some underlying neither-wave-nor-particle stuff. — Wayfarer

Yes I can. What’s the problem with this?

The answer you get depends on the question you ask, and you're severely limited in infering what is the case beyond that - or rather, there's nothing in physics which will provide you with a warrant for that kind of speculation. — Wayfarer

How does this relate to what I’m saying?

That there isn't 'a particle'. You're observing different results, but they're not 'of' something that acts in a certain way. — Wayfarer

?

What are you “observing” if not something acting a certain way?

boethius

But it’s not just “updating the model with new information” is it? — khaled

In science, yes, that is what is happening.

If we don't have new information, we cannot say what is happening other than the probability distributions that we already have based on old information.

If you make a claim about what is happening, how can that claim be verified?

By getting new information through new observations.

Talking about what is happening without any actual information about what is happening, is pseudoscience. It maybe true, it maybe false, but it's not a scientific claim that can be verified by experiment.

I appreciate the long explanation but there is nothing there I didn’t already know. — khaled

I very much doubt this is true.

khaled

↪boethius

If we don't have new information, we cannot say what is happening other than the probability distributions that we already have based on old information. — boethius

Point is, these probability distributions are “ontological” for QM. It’s not that there “really is an electron somewhere” we just don’t know where, the electron “is really everywhere” in the probability distribution. Otherwise you wouldn’t get interference patterns.

That’s what I mean by not JUST updating the model with new information. Observations in QM change what is happening, not just what we think is happening. It’s not like when the probability distribution of the location of the drowning person “collapses” when we see them, but really, there was always a person there even without us observing them.

In QM that collapse has physical effects: such as there being interference without the collapse and no interference after. There was no “electron really there”.

I very much doubt this is true. — boethius

I don’t. But I don’t care to start playing “you just don’t get it” games. If that’s your intention I’m just going to leave.

And what happened to the argument from evolution? Maybe coming from someone else it’ll make more sense?

"The evolution of conscious life on this planet is due to appropriate mutations having taken place at various times. These, presumably, are quantum events, so they would exist only in linearly superposed form until they finally led to the evolution of a conscious being—whose very existence depends on all the right mutations having 'actually' taken place!"

-Roger Penrose.

Wayfarer

We can't say that they are attributes of some underlying neither-wave-nor-particle stuff.
— Wayfarer

Yes I can. What’s the problem with this? — khaled

The point is that it can't be known. If it were simply a matter that 'electrons can either appear as waves or particles'. again, there wouldn't be any problem of intepretation.

For that matter, why do you think there is a problem of interpretation? What is this thread about?

khaled

↪Wayfarer

Problems of interpretation come from trying to explain why the electron sometimes appears as a particle and sometimes a wave.

boethius

Point is, these probability distributions are “ontological” for QM. It’s not that there “really is an electron somewhere” we just don’t know where, the electron “is really everywhere” in the probability distribution. Otherwise you wouldn’t get interference patterns. — khaled

This is literally what I explain, as the electron somehow "co-existing" in detached regions.

What is at issue is what to make of this.

That’s what I mean by not JUST updating the model with new information. Observations in QM change what is happening, not just what we think is happening. — khaled

That's not a problem. The model includes these interactive effects, so when we measure position precisely of a particle we update the model with this increase in constraint on position but also decrease the constraint on momentum.

We can do all this without making any ontological claims as to what exists apart from our calculating and measuring. This is where the "shutup and calculate" expression comes from; it works and it doesn't "have to" make any intuitive sense nor does one "have to" take a position on the ontological status of the electron apart from variables being more or less constrained in mathematical models that take real world inputs.

We take information from the real world, we put it in a model, we get information out that corresponds to future information we can take from the real world. This is all that "we know" is happening. What happens between information gatherings we don't know.

In the case of the classical "probability waves" of large objects, even if the above is true "in principle", we are free to imagine the drowning person somehow co-exists is in all possible locations and the possibilities "collapse" to one possibility when we find them (how do we check if the person is "really somewhere", we need to go and find them and check), nevertheless, the assumption that the person is "really somewhere" doesn't run into intuitive problems (the statistical model is completely compatible with this assumption).

In the case of quantum mechanics, not only is it a problem "in principle", but it's also a problem that our intuitions about how "real objects" should behave simply don't work.

If there was an obvious conclusion to be drawn, the best physicists of the last hundred years would have drawn it and all agreed.

I think Feinman says it best when he describes "doing quantum mechanics" as the same state of knowledge as Mayan priests (I think it was Mayan) calculating the next eclipses. They've discovered a pattern, and they can do the calculations and make predictions and those predictions come true, but they have no knowledge of orbital mechanics and what is "really happening". So, any explanation the high priest gives is complete speculation and doesn't seem much better than plenty other explanations available. In such a state of knowledge where the "true causes" are simply lacking, we just have a mathematical pattern of what we observe, "these are lucky numbers for the Sun God" is going be just as reasonable to believe as "things are floating up there and they can block each other ... coincidentally following the pattern we've discovered for some reason".

And speculation is fine; I'm simply arguing that unless there's an experiment that proves one equally reasonable speculation is more credible than another ... one equally reasonable explanation is not more credible than another.

And mostly, interpretations boil down to ontological positions that predate quantum mechanics. "Everything that can happen does happen," is a very old concept. Likewise, we simply can't know what reality is "really like", goes thousands of years before Kantian skepticism. Similarly, there is a specific state of the universe and the future is fully determined is also an old idea.

All we are doing in this conversation is throwing in some quantum jargon, which is useful because it can help readers here understand quantum mechanics a tiny bit better, but doesn't really setup anything really different in the speculations available. We know quantum mechanics "is wrong" and maybe a better theory lends itself to one over another speculation, just as Newtonian physics lends itself to a deterministic interpretation and Quantum Mechanics, at least on the surface viewing, lends itself to Kantian style skepticism of "not knowing anything about things in themselves"; but QM isn't "proven" as some sort of end all and be all of physics, so maybe some future theory gives us other indications about "the true ontology" (and perhaps equally misleading as the indications of Newtonian, General Relativity, and Quantum Mechanics).

It’s not like when the probability distribution of the location of the drowning person “collapses” when we see them, but really, there was always a person there even without us observing them. — khaled

Yes, we are "JUST" updating the model with the new information, but in quantum mechanics updating the model with new information can impact on the model in ways that aren't intuitive. If we measure a particles location precisely (constrain that variable) it also changes constraints on momentum, and we may now know less about the particles momentum than we did before. We do not need to make ontological assumptions about what "really exists" between measurements to make use of quantum mechanics.

boethius

"The evolution of conscious life on this planet is due to appropriate mutations having taken place at various times. These, presumably, are quantum events, so they would exist only in linearly superposed form until they finally led to the evolution of a conscious being—whose very existence depends on all the right mutations having 'actually' taken place!" — khaled

I've already mentioned, it can just be supposed that all the possibilities propagate, including ones in which evolution happens, and the first possible consciousness collapses the cosmic wave function. No problem, no one's conscious before that to say otherwise, perfectly explains why we live in an extreme probability edge case, based on what we know of quantum mechanics so far, that there's more matter than antimatter for instance.

Of course, if, why and how this happens is pure speculation. The difference is that I'm labeling my speculations as speculations.

Wayfarer

Problems of interpretation come from trying to explain why the electron sometimes appears as a particle and sometimes a wave. — khaled

Well you’re certainly right in saying that there would be no problem of interpretation if there was no problem of interpretation.

khaled

↪Wayfarer

you asked me why there is a problem of interpretation....

Wayfarer

↪khaled

And you answered, 'because there's a problem of interpretation'. You didn't say why there's this problem.

khaled

↪boethius

If there was an obvious conclusion to be drawn, the best physicists of the last hundred years would have drawn it and all agreed. — boethius

I mean.... that is pretty much what happened when it comes to whether or not consciousness is necessary. They basically all drew the conclusion that it isn’t. That’s one of my first arguments.

We do not need to make ontological assumptions about what "really exists" between measurements to make use of quantum mechanics. — boethius

But we can KNOW that the electron, unlike the drowning person, doesn’t “really exist somewhere” that we are finding out correct? Or else interference effects wouldn’t happen.

So we can make some ontological deductions. We can know that the electron wasn’t “really anywhere” but was “really everywhere”. It has to be. Or interference wouldn’t occur.

But regardless:

I've already mentioned, it can just be supposed that all the possibilities propagate, including ones in which evolution happens, and the first possible consciousness collapses the cosmic wave function. No problem, no one's conscious before that to say otherwise — boethius

And DESPITE, no one being conscious before to say otherwise, we know certain things happened at certain times. We know the age of the earth for example, when it formed, which species existed when, etc. We shouldn’t be able to know these things without any consciousness to collapse the wave functions at the time.

What you’re suggesting here is that in the xyz-time “block”, you start from time = 0 and as you move along particles take every which path available to them. But the second one of these paths hits consciousness, suddenly, the awesome power of consciousness causes collapse “back in time” correcting history so that only one path happened all along. This contradicts what you say here:

It is not the case that when the wave functions "collapses" that a particle is then considered to have taken a definite path, only the properties observed become more definite for the time of observation, but it is still the case that the particle in some way (we really don't understand) when through all possible paths to get to that observation point — boethius

Again, if the above is true (and I agree it is) and consciousness was the only thing capable of causing wave function collapse, then all we SHOULD be able to know about the world before we evolved is that it was all some quantum soup with everything being everywhere. But we clearly know more than this. Even though there was no one around to collapse wave so that certain events would “really happen” before us.

This is true regardless of whether you want to consider QM as justifying certain ontological assumptions or not. Even if we are speaking purely in terms models about what we know: If consciousness was required for collapse, we shouldn’t know anything about the time before consciousness emerged, yet we do. How?

khaled

↪Wayfarer

what’s your answer?

Wayfarer

I’ve given one, I’m asking you.

khaled

↪Wayfarer

I need to see it to know what you consider an acceptable answer. Because to me the question sounds like:

"Why is 1+1=2"
"Well, when you put 1 and 1 things together you get 2 things"
"Oh, so 1+1=2 because 1+1=2 now? You haven't explained why"
"Why else do you think"
"I've explained my position, I'm asking you!"

Wherever multiple interpretations are available people will be arguing which is better or which is even valid. But that's not a good enough answer, so what is?

boethius

I mean.... that is pretty much what happened when it comes to whether or not consciousness is necessary. They basically all drew the conclusion that it isn’t. That’s one of my first arguments. — khaled

They don't all agree on an interpretation. I don't see where you get this, maybe read some of @Wayfarer''s posts.

But we can KNOW that the electron, unlike the drowning person, doesn’t “really exist somewhere” that we are finding out correct? Or else interference effects wouldn’t happen. — khaled

No, we can't know. We can't know if the person is in a superposition of possibilities, unless we go and check and make an observation.

You are claiming to know? How would you backup your claim? By going and finding the person and pointing to a definite location the person is in, or then making other observations that at least constrain the possibilities. Does that establish you "know" the person is in a definite position before you go and check? No, it doesn't establish that.

And DESPITE, no one being conscious before to say otherwise, we know certain things happened at certain times. — khaled

We do not know.

The whole cosmic wave function could have been happily existing in its quantum splendor representing all possibilities a conscious being might see, and only collapse due to a conscious being existing in one possibility and therefore the cosmic wave function collapses to a coherent single, or at least greatly constrained, possibility.

What you’re suggesting here is that in the xyz-time “block”, you start from time = 0 and as you move along particles take every which path available to them. But the second one of these paths hits consciousness, suddenly, the awesome power of consciousness causes collapse “back in time” correcting history so that only one path happened all along. This contradicts what you say here: — khaled

It does not "correct history".

The other possibilities "go away" upon observation, just like any other experiment.

How do we, or "the universe", know there's an observation that has happened? Because someone or something becomes conscious of the observed results.

There is no correcting history, obviously our "definite universe" is a coherent possibility, just as any other; it's just the other possibilities "went away" somehow for some reason. Before anyone was conscious of what possibility the universe is actually in, there's no way to go back and check whether the possibilities co-existed in a quantum probability wave sense (or any sense) or then definite situations followed one to the other even if there was no one around to see it.

khaled

↪boethius

They don't all agree on an interpretation. — boethius

That's why the word "basically" is there. It's definitely a statistical majority. Which is as good as you're going to get.

No, we can't know. — boethius

Yes we can because if it did the interference pattern wouldn't emerge.

How would you backup your claim? — boethius

As above.

Does that establish you "know" the person is in a definite position before you go and check? No, it doesn't establish that. — boethius

No but if throwing a bunch of people through two slits produces the result that the people act as "waves" until measured that precisely means that they don't act as particles all the time. In other words, that the people are "truly everywhere" in the probability distribution.

Now replace people with electrons.

Or in other words, if the electron really did exist as a particle in a spot, with a certain momentum, how do you explain why an interference pattern emerges when we don't measure the electron's location?

The other possibilities "go away" upon observation, just like any other experiment. — boethius

No, not just like in any other experiment. In fact very unlike every other experiment. See here:

It is not the case that when the wave functions "collapses" that a particle is then considered to have taken a definite path — boethius

Except in this case... For some reason in this one case, when collapse happens at time t5, it also happens backwards for times t1,t2,t3,t4. It's either that, or everything we know about Cosmology is just wrong, and we can't really know it.

Before anyone was conscious of what possibility the universe is actually in, there's no way to go back and check whether the possibilities co-existed in a quantum probability wave sense (or any sense) or then definite situations followed one to the other even if there was no one around to see it. — boethius

You claim this. But it's clearly false. We know definite situations followed one to the other even though no one was around to see them. That's what Cosmology establishes. By your theory we shouldn't be able to do cosmology. Since waves don't collapse unless seen by a conscious agent, and since we can't see the past, we should not be able to know anything about it. It should just seem like quantum soup.

boethius

That's why the word "basically" is there. It's definitely a statistical majority. Which is as good as you're going to get. — khaled

Is it a majority? Where's your data?

But, even so, who cares?

If a majority of physicists in the time of Newton believed physics was fully determined (or then to arbitrary precision of all variables such as position and momentum), did that conclusively prove anything at the time?

All communities are affected by "group think", and the point of science is that real experiments can settle differences, not votes. If a bunch of physicists "voted" about something, really, who cares about that? Do the physicists themselves even care about it more than just an opinion poll of the moment that obviously doesn't "prove" anything?

If a majority of physicists were defending your point of view, where's their experiment to prove it? Are you really defending the idea that these physicists would say "ah, ah, ah, not so fast, we're a majority and therefore correct"?

Yes we can because if it did the interference pattern wouldn't emerge. — khaled

What does this point make? We agree the electron cannot be said to be "at one place" when we aren't observing it (even though there are fully deterministic theories where the particle is "at one place" at all times, but we seem to agree on at least this point; still, worth making a note of), and we agree that the "substance" of the electron, in some sense, is represented by the probability distribution, which has wave characteristics and can interfere with itself to make interference patterns etc.

What we're debating is what happens to this "probability related substance" when a measurement is made.

My point is that to "know" a measurement is made is to become conscious of the measurement result. The "probability waves going away" happen at that moment or before. If you argue "before", how do you prove it? In science you need to go and check, but this just kicks the can up the road, as @Wayfarer has really described super well, so read his comments. I'm just adding some quantum math lingo to what Wayfarer has already adequately described (and my math lingo I'm adding just to explain to you, or other readers here interested, that the math lingo doesn't really change the philosophical arguments of principle that pre-existed Quantum Mechanics, of determinism, skepticism, solipsism, panpsychism, everything possible actually happens in eternal infinite chaotic universe, etc.; although if a poster here knows of an interpretation of QM that does not map "pretty well" to pre-existing philosophical arguments, it would be interesting to add it to the mix).

As above. — khaled

You backup your claim by just asserting "physicists agree with you", without providing any "well controlled experiment" of how this is even supported?

No but if throwing a bunch of people through two slits produces the result that the people act as "waves" until measured that precisely means that they don't act as particles all the time. In other words, that the people are "truly everywhere" in the probability distribution.

Now replace people with electrons.

Or in other words, if the electron really did exist as a particle in a spot, with a certain momentum, how do you explain why an interference pattern emerges when we don't measure the electron's location? — khaled

I don't know what we're debating here. I've said our knowledge about the person lost at sea is a probability distribution (labeling it a "wave" or not doesn't matter), my point is that if you claim the person is "really somewhere" and not somehow "co-existing" in all the places they can be according to what we know, how do we prove they are "really somewhere"? We go and check.

As for making interference patterns with people; so far there is no known bound for making interference patters with atoms, so in principle, as far as we know, it's possible with people too. Of course, you'd need to cool them incredible close to absolute zero and you may need literally hundreds of trillions of throws to see any pattern in a whole bunch of noise, as well as do the experiment in deep inter-galactic space; but, until we find an upper bound of number of particles for making interference patterns, we can't say we can't do it with "people too" (well, at least the particles making up their bodies).

Except in this case... For some reason in this one case, when collapse happens at time t5, it also happens backwards for times t1,t2,t3,t4. It's either that, or everything we know about Cosmology is just wrong, and we can't really know it. — khaled

Collapse does not happen backwards. All the possibilities related to t1, t2, t3, and t4 can be still "in play" and those possibilities are still co-existing at t5 as well, but when we make a measurement at t5, all the other possibilities "that could have happened" go away.

Cosmology only tells us that now, when we look up at the stars, we see starts in definite locations corresponding to a definite history we can piece together. There is zero problem saying plenty of other possibilities "co-existed" until the first consciousness emerged to make such observations to collapse the wave function. Definiteness occurs at observation, how would we check it occurred before? We'd have to go and observe what occurred before, defeating the purpose of the checking.

You claim this. But it's clearly false. We know definite situations followed one to the other even though no one was around to see them. That's what Cosmology establishes. By your theory we shouldn't be able to do cosmology. Since waves don't collapse unless seen by a conscious agent, and since we can't see the past, we should not be able to know anything about it. It should just seem like quantum soup. — khaled

I really don't see where you get this. All possible cosmologies propagate from the big bang, and then the cosmic wave collapse happens and one definite cosmological history is "retained" once a "sufficient" consciousness emerges (in at least one of the possible cosmologies) and the wave function collapses.

This theory explains fine-tuning, and also solves the problem of the universes splitting and questions about energy conservation and quantum information copying (which if universe splitting doesn't just ignore, I haven't seen any experimental evidence proving this isn't a problem); however, we know probability waves can and do exist without violating information or energy conservation, so the entire cosmos in such a state creates zero problems in this regard. Maybe inflation was a super low probability event, likewise matter and antimatter asymmetry, weakness of gravity, and so on, but the first consciousness emerged in this super probability edge case, so that's what we see. Why is humanity so stupid? > edge case, "sufficient consciousness" is a pretty low bar.

khaled

↪boethius

As above.
— khaled

You backup your claim by just asserting "physicists agree with you", without providing any "well controlled experiment" of how this is even supported? — boethius

I did provide experiments. And clearly not I back it up by saying:

Yes we can because if it did the interference pattern wouldn't emerge. — khaled

That's what was above the words "as above". To remind you the claim was:

But we can KNOW that the electron, unlike the drowning person, doesn’t “really exist somewhere” that we are finding out correct? Or else interference effects wouldn’t happen. — khaled

Which you agree with here:

and we agree that the "substance" of the electron, in some sense, is represented by the probability distribution, which has wave characteristics and can interfere with itself to make interference patterns etc. — boethius

To rephrase the claim: I was saying that we can know for a fact that the "substance" of an electron is not a particle in one place when we are not observing it. That's an ontological claim.

This was in response to your claim that Quantum Mechanics can't say anything ontological. Yes it can. "That the substance of an electron is not a particle in one place when we're not observing it" for example.

But, even so, who cares? — boethius

Ah I see, so when I say that "The majority of physicists agree that this interpretation is false" then it's "who cares" but when you say "If there is an obvious interpretation physicists would have agreed on it" expert opinion suddenly matters. If you remember, I was only following what you said. You said if there is an obvious interpretation that physicists would have agreed on it. Well, physicists agree that consciousness is not necessary for collapse. Shouldn't that make it the "obvious conclusion" then? Oh no but who cares about expert opinion at all.

To emphasize, I didn't say that experts agreeing makes them correct. You're the one that started by giving significance to expert opinion which I only used to support my argument.

I don't know what we're debating here. — boethius

Whether or not quantum mechanics can lead to valid ontological claims about electrons (for example), instead of just epistemological claims.

so in principle, as far as we know, it's possible with people too — boethius

For massive objects the probability distribution is incredibly small. From the uncertainty principle equation: For massive objects there is always going to be a (relatively) large uncertainty in momentum (since they're massive) which means a very small uncertainty in position.

Definitely not enough to produce an interference pattern of any sort. So no, we know we can't do it with people. Moreover, if you still want to stick to the "consciousness causes collapse" theory then we DEFINITELY can't do it with people, because the people will collapse their own wave function!

Collapse does not happen backwards. All the possibilities related to t1, t2, t3, and t4 can be still "in play" and those possibilities are still co-existing at t5 as well, but when we make a measurement at t5, all the other possibilities "that could have happened" go away. — boethius

"Those possibilities are still co-existing except they go away"

Excuse me what?

Definiteness occurs at observation, how would we check it occurred before? how would we check it occurred before? We'd have to go and observe what occurred before, defeating the purpose of the checking. — boethius

Exactly. So we shouldn't have any clue what happened at times t0,t1,t2,t3,t4 since we can't go and check. But we do. So maybe definiteness doesn't require conscious observation?

There is zero problem saying plenty of other possibilities "co-existed" until the first consciousness emerged to make such observations to collapse the wave function. — boethius

Except that would mean that it caused collapse back in time. It "corrected history".

All possible cosmologies propagate from the big bang, and then the cosmic wave collapse happens and one definite cosmological history is "retained" once a "sufficient" consciousness emerges (in at least one of the possible cosmologies) and the wave function collapses. — boethius

"One definite cosmological history is retained". So... Correcting history with the awesome power of consciousness?

The only way I can make sense of this is if you're trying for some MWI of some sort but it doesn't seem like you are.

The "probability waves going away" happen at that moment or before. If you argue "before", how do you prove it? — boethius

By the fact that there are consequences if it didn't happen before which we can test for. Again, cookie dispensers and double slit experiments.

Also because if it didn't happen before, then you're saying that we can't know anything about the state of the world before the observation. Yet cosmology exists.

Metaphysician Undercover

Problems of interpretation come from trying to explain why the electron sometimes appears as a particle and sometimes a wave. — khaled

I think the issue here is that the electron does not have any real existence as a particle at all. It is a particular quantity of energy, and we, as human beings desire to give that quantum of energy real existence as a unit, making it an entity, called an electron. But there is no real existence of that particle, this is simply how we relate to that energy from our perspective as human beings, with human artifices.

Good physics

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