Shameful. You make a claim, "I'm saying it isn't ABOUT human decisions," and I ask why not, and you have no answer. Are you suggesting that QM has nothing to do with people? Nothing to do with anything larger than a breadbox? And given what's said above, it appears you're making a positive claim based on ignorance. You've let your excitement get the better of you. Let's try to reel it in. You buy MW. Ok, my question to you is, is there one universe? Or are there many universes? What say you?

What do you think I am flailing about, about? MW may be a description that solves some problems, but it seems to me that it imposes far greater problems. That is, that the most unlikely of one-universe solutions is still far more likely than multiple universes flashing into existence in far greater than vast numbers. That based on my understanding of basic MW that at every event, the universe divides to accommodate all possible outcomes.

Bottom line, there's reality, as best it can be grasped, and models and descriptions of the reality. The model/description never itself being the reality in question - notwithstanding any value as predictive.

It seems to on any macro-scale. The "seems to" not just a throwaway phrase, but rather a pretty good clue as to what is, er, seems to be, the case. The real trick here is to not use the "I don't knows" as grounds for knowing. — tim wood

What seems to be, often is not what is the case. The issue is the nature of what has been called "persistence" in this thread. And although we take persistence for granted, as indicated by Newton's first law of motion, it is demonstrably not a necessity, not necessary. That things will continue to be, as they have been in the past, is not a necessity. This is what Hume pointed to with his discussion of causation and the problem of induction, the necessity required for solid, sound conclusion of certainty, just is not there. Even Newton stated that his first law of motion was dependent on the will of God. He noticed that what this law takes for granted, that a body will continue to move, as time passes, with the same motion that it had in the past, unless caused to change, is not a statement of necessity. It is an inductive conclusion, and such conclusions lack necessity, as Hume argued.

So there is another way to look at the persistence of objects, a way which does not take for granted the continuity of existence, the persistence, which is expressed by Newton's first law. When we do not take this law for granted, then we see that what is expressed by this law requires a cause. So for example, if a body is going to continue to move in a predictable, uniform way, then at each moment as time passes, there must be a cause which makes it be at that particular predictable place. From this perspective, we do not take for granted that the body will move in a predictable way, as described by Newton's law, we understand that there must be a cause of it moving in that predictable way, and so this cause is acting on the body at each moment of passing time, making it exist at the place where the prediction dictates.

And you know this how? — tim wood

I know this by inductive reasoning. Every real physical body, object, or thing, has a location. If it does not have a location it is a fictional thing. If you are not inclined to believe that inductive reasoning can give sound premises, and you recognize that it is lacking in necessity, then you are in a good position to understand what I wrote above.

My private opinion is that the electron is particle-like, and only cloudlike in the sense that it moves around really, really fast. And it would not offend my scientific sensibilities if someone were to suggest that maybe the particle-like in its motion sets up a kind of standing shock wave, though in what medium or made of what I don't know. — tim wood

Why then does electrical energy travel through the field around copper wires, instead of traveling through the copper wires, where the electron particles are supposedly located? Or do you think that particles of the wire, the electrons are actually outside the wire?

However, electrical energy does not travel though the wire as sound travels through air but instead always travels in the space outside of the wires. This is because electric energy is composed of electric and magnetic fields which are created by the moving electrons, but which exist in the space surrounding the wires. — http://scienceline.ucsb.edu/getkey.php?key=3199

What seems to be, often is not what is the case.... So there is another way to look at the persistence of objects.... When we do not take this law for granted, then we see that what is expressed by this law requires a cause....From this perspective, we do not take for granted that the body will move in a predictable way.... I know this by inductive reasoning.... It is an inductive conclusion, and such conclusions lack necessity.... Every... thing has a location. If it does not have a location it is a fictional thing. — Metaphysician Undercover

It would be nice if you did not spend so much time trying to hammer ordinary pegs into your peculiarly shaped holes. As to cause, one of the basic presuppositions of Newtonian science, Newton held that some things were caused and some things were due to the operation of law. In any case, if you insist on causes, I shall ask you to make clear exactly what a cause is. And before you take that on, you should know that modern science for the most part does not use the concept of cause, except as a convenient fiction for occasions when precision of expression is not required - but you go ahead if you want to.

Bell described machines that with certain inputs produce reliably consistent outputs. In looking at those inputs and outputs, he devised a formula now known as Bell's inequality that appears to establish a limit on those outputs, which experimentally is violated. And this QM weirdness, in this and other experiments, has resulted in no end of people claiming both to know what they do not know, and to know because they do not know, and as a result, claiming to know how it all works, which no one knows. It ought to be enough to simply ask such people, "How do you know?" But the scale of evasion when faced with this question is often stunning. And not to be confused with the respectable scientific endeavor of trying to create or discover models or theories that are appropriately predictive, and sensible - no virgins for the volcano god.

But you it seems would take a bit of snake, and of newt and frog and bat and dog, and some other ingredients, and boil up a potion that you would call knowledge, but in fact is nonsense or worse. So, for any of your "conclusions" in your posts, never mind all your qualifications and variant perspectives, how do you know?

you brought the tone of the conversation too low with that "shameful" bit. You gotta grow up a little bit man. You shouldn't get so worked up about qm, it's not that big of a deal that someone likes one interpretation or another. Please relax about it.

I'm happy to humour your curiosity about many worlds, but not if I'm just being insulted. I don't believe I insulted you.

Fine. Questions pending. Can you handle them? They're just above. My own view is that QM applies to everything. If complete - which I think it is not at present - there will be seen ultimately to be no mysteries. If not complete, then QM is just a holding theory awaiting its replacement (or if it's the best that can be done, then humanity doomed to Ignorance.) And in saying this, I'm not saying much. As to many-worlds, I am under the impression it calls for the endless instantaneous creation of many worlds. I confess to near total ignorance as to what use such a theory can be, unless to introduce magic and the ultra-supernatural as explanatory principles in physics. Can you rescue either me, or it?

The use of many worlds is arguably the same use as quantum mechanics. It's a natural interpretation of quantum mechanics given the mathematics. In fact quantum computing was partly developed by a guy who had the idea to do it because he wanted to prove many worlds. So if you think quantum mechanics is useful, and especially if you think quantum computers have the potential to become useful, you have a framework for understanding why many worlds might be part of something useful.

"Instantaneous creation of worlds", I think creation is the wrong word there. This is one of those points where there's interpretations within interpretations. Are worlds created, do they already exist, are they just splitting? I'm not into the "created" phrasing, but I guess for a casual conversation it's close enough.

Yes, worlds are splitting or getting created or however is the proper way to word it (decoherence is the central concept here), due to quantum events, constantly. But again, that doesn't necessarily mean every choice you can imagine is realized in some world somewhere. I don't think so, anyway. There are cases where worlds are split at the joint of human choices, but I think those are the exception rather than the rule.

If you want a canonical answer on that, I'm not the guy to provide that. This is just my opinion.

This is just my opinion. — flannel jesus

Opinion and cogency all we got, most of us, for the most part. We do get to ask, "Does that make sense?" and, "How do you know?"

I suppose by decision, we mean that instant when a particle can do one thing or another, become one thing or another, or go one way or another. MW I suppose to mean that for every option at every moment, a new world is (actually!) created in which every option is realized. And to me that sounds like language and thinking visiting fantasy land.

The notion that QM involves any splitting/creation is new to me. I buy, e.g., quantum tunneling as observed phenomenon, and accept that the math of it applies to objects of any size. But not that QM permits creation ex nihilo (pace virtual particles).

And to me the main problem of changes to accommodate the needs of interpretation, as in QM the particle's being either wave or particle as needed, is simply, how does the particle know? What is the medium in which the "decision" is made or transmitted? "Spooky action at a distance" is just a black-box of an answer, giving no account whatsoever of how it works.

The sum of questions like these is not to get detailed accounts of what actually happens - I wouldn't understand them anyway. But to attempt to draw the lines on one side of which is, or seems to be, manifest nonsense, and on the other at least reasonable plausibility - details left to experts. The purpose of questions like these, at my level anyway, is the attempt to block nonsense. Because nonsense left to breed can cause real trouble, examples of which abound.

You're certainly allowed to think many worlds is nonsense. Many experts in QM agree with you.

And many experts in QM also disagree. Many worlds is, as far as I can tell, the second most popular interpretation among experts. I think you'd find the first most popular also disagreeable, though, so...

John Bell himself, after which this thread is named, interestingly thinks simultaneously that Many Worlds is absurd and simultaneously a promising approach to qm. He respects it and thinks it's nonsense at the same time (or did, anyway)

I have no means of convincing you, or interest in doing so. All I can do is chat a bit about it. I think it's interesting.

Why then does electrical energy travel through the field around copper wires, instead of traveling through the copper wires, where the electron particles are supposedly located? Or do you think that particles of the wire, the electrons are actually outside the wire?

However, electrical energy does not travel though the wire as sound travels through air but instead always travels in the space outside of the wires. This is because electric energy is composed of electric and magnetic fields which are created by the moving electrons, but which exist in the space surrounding the wires.
— http://scienceline.ucsb.edu/getkey.php?key=3199 — Metaphysician Undercover

I'm afraid your source is not very good. It seems to be mistaking the skin effect which is applicable to AC signals, for a general rule about electrical conduction.

In either the AC or DC case, electrical current travels through the conductor. That link provides some explanation as to why in the AC case the conduction of current becomes more and more confined to the outermost portions of the conductor as the frequency of the AC signal increases.

To give an idea of the caliber of writer SA used to employ: — hypericin

I subscribed back in the 1970s. I finally gave up because so many of the articles were over my head. I didn't take another look until the 2000s. Might as well read "Discover."

I have no means of convincing you, or interest in doing so. All I can do is chat a bit about it. I think it's interesting. — flannel jesus

And TPF being the kind of site that it is, I am asking you what you think. Does MW make sense to you as a real thing? I think it's absurd. Absurdity can be a road to sense, but it does not stop the absurdity from being absurd. In the case of MW, I don't happen to see the sense that it might lead to.

Back to Bell's, I posit that either something must happen to the particle(s) that they violate the inequality, the something that happens yet to be discovered. Or that nothing in particular happens to the particle(s), meaning that the particles themselves, being able out-of-the-box to violate the inequality, are not well-understood. And the series of Bell tests appear to have shown that what it would be about the particles that "enables" them will be very hard to figure out and determine - so-called hidden variables being so far ruled out.

And TPF being the kind of site that it is, I am asking you what you think. Does MW make sense to you as a real thing? — tim wood

Yeah. I'm not religious about it. I'm not certain of it, I don't think people are going to hell for disagreeing with it, I don't think only stupid people reject it. I just think it's the most compelling option.

I just think it's the most compelling option. — flannel jesus

I get that; you've been clear. Allow me to try this: if you will simply buy this deed I have to this bridge and the underwater land under the bridge, which today only I am having a sale on, you will get rich! Compelling? Are you getting out your checkbook? I can hope you would have to make clear to your conservator why you think buying my deed is compelling, at least enough to buy. In a sense on TPF we submit and subject ourselves to a kind of conservatorship of thinking by our TPF brothers. So why do you think MW is worth your favor? What is wrong or mistaken in my thinking it's an absurdity?

Many worlds is worth my favour because it provides the clearest account of what happens across the variety of quantum experiments, without resorting to too many unsavoury assumptions.

You might think a multiplicity of worlds is an unsavoury assumption already, but the alternatives are arguably, and in my estimation, even worse.

The major alternative is Copenhagen, which has the following features:

* genuine randomness
* non local casualty
* an additional arbitrary postulate on top of non local causality to explain why you can't use that non local causality to communicate faster than light

The first of the above isn't that bad, but the other two are pretty undesirable in a physical theory.

Another alternative to MWI involves accepting retro causality, which I don't like.

Basically, every alternative to MWI involves accepting stuff that is even harder to stomach than invisible alternate worlds. And believe it or not, MWI is actually *simpler* than the alternatives. So it deserves a couple points from Occam's razor

To me MW is only palatable if the "worlds" are virtual, not actual. The universe consists of a finite set of resolved state and an infinite, virtual, unresolved state: the set of everything that is consistent with what is resolved. There are infinite possible worlds which are consistent with what is actual.

So for instance, an electron cloud represents all the probabilities of locations an electron may be that is consistent with the position of the nucleus (itself a tighter cloud), and the surrounding fields. These can be thought of as virtual versions of the world, and none is more actual than any other, just more or less likely. The infinite worlds collapse to a definite state of affairs when interaction with other definite states of affairs make it necessary. But this then is just the basis for a new set of virtual possible worlds.

So in the Bell experiments the two particles don't have a definite spin, the actual, resolved world is consistent with an infinite number of potential spins they may have. When they encounter a magnetic field, these virtual worlds collapse to an actual one where one has one definite spin, and the other the opposite. Since there is no consistent world where the particles have anything but opposite spins, the collapse creates the appearance of action at a distance.

This combines the genuine randomness of Copenhagen with the "out" for non-local causality of MW, without the egregiousness of gigatons of matter being created every nanosecond, at every point in space (I don't know if anyone actually believes that last bit).

Is this kind of interpretation a "thing", or am I talking out of my ass?

So in the Bell experiments the two particles don't have a definite spin, the actual, resolved world is consistent with an infinite number of potential spins they may have. When they encounter a magnetic field, these virtual worlds collapse to an actual one where one has one definite spin, and the other the opposite. Since there is no consistent world where the particles have anything but opposite spins, the collapse creates the appearance of action at a distance.

This combines the genuine randomness of Copenhagen with the "out" for non-local causality of MW, without the egregiousness of gigatons of matter being created every nanosecond, at every point in space (I don't know if anyone actually believes that last bit).

Is this kind of interpretation a "thing", or am I talking out of my ass? — hypericin

It's an interesting idea, but on the surface I'm not actually sure how it functionally is different from Copenhagen. At the moment one particle gets measured, by exactly what mechanism does the other particle know to come out measured the opposite? If it happens immediately, it's spooky action at a distance. If it doesn't happen immediately, then what does the narrative look like?

At the moment one particle gets measured, by exactly what mechanism does the other particle know to come out measured the opposite? — flannel jesus

When particles s,t are emitted, there are infinite virtual worlds where s,t can have any allowable spin. But crucially, these are the same virtual worlds, since their spins are linked. Upon measurement of s to have spin +A along one axis, the virtual worlds collapse to an actual state of affairs, where s has +A, and t has -A. The particles don't "know" anything, their spin just belonged to the same set of virtual worlds.

the virtual worlds collapse to an actual state of affai — hypericin

collapse *immediately*?

I think so, yes.

I'm no expert, take this with a grain of salt, but I do believe you've described Copenhagen to a t. Including the virtualized worlds concept (it may not be standard to call it that in Copenhagen, but I believe the idea is basically that).

Or, perhaps it's a flavour of Copenhagen. Basically, it has a lot in common with Copenhagen, from my point of view.

Cool, I don't know either if this meaningfully diverges from Copenhagen or not.

If it is Copenhagen, does this slant make it any more agreeable to you?

if the community of physicists is anything to go by, Copenhagen-type interpretations are certainly valid and worth consideration. I definitely consider them a genuine possibility.

To me MW is only palatable if the "worlds" are virtual, not actual....
So for instance, an electron cloud represents all the probabilities of locations an electron may be that is consistent with the position of the nucleus (itself a tighter cloud), and the surrounding fields. These can be thought of as virtual versions of the world, and none is more actual than any other, just more or less likely. The infinite worlds collapse to a definite state of affairs when interaction with other definite states of affairs make it necessary. But this then is just the basis for a new set of virtual possible worlds.

So in the Bell experiments the two particles don't have a definite spin, the actual, resolved world is consistent with an infinite number of potential spins they may have. When they encounter a magnetic field, these virtual worlds collapse to an actual one where one has one definite spin, and the other the opposite. Since there is no consistent world where the particles have anything but opposite spins, the collapse creates the appearance of action at a distance.

This combines the genuine randomness of Copenhagen with the "out" for non-local causality of MW, without the egregiousness of gigatons of matter being created every nanosecond, at every point in space (I don't know if anyone actually believes that last bit). — hypericin

At the moment one particle gets measured, by exactly what mechanism does the other particle know to come out measured the opposite? If it happens immediately, it's spooky action at a distance. If it doesn't happen immediately, then what does the narrative look like? — flannel jesus

When particles s,t are emitted, there are infinite virtual worlds where s,t can have any allowable spin. But crucially, these are the same virtual worlds, since their spins are linked. Upon measurement of s to have spin +A along one axis, the virtual worlds collapse to an actual state of affairs, where s has +A, and t has -A. The particles don't "know" anything, their spin just belonged to the same set of virtual worlds. — hypericin

Imho, an excellent exchange (I would only edit in what I think you meant, that the particles "don't have a definite spin" until measured) and it seems to me the last part is what is meant by "entanglement."

As to randomness, I'll add this: that randomness is really hard to define. I suspect that at the level of the things themselves, nothing is merely random, for reasons I think obvious (yes?). That leaves open the question as to whether QM events at some level must always be inaccessible to us, and thus necessarily and as a practical matter always random to us.

it seems to me the last part is what is meant by "entanglement." — tim wood

:up:

As to randomness, I'll add this: that randomness is really hard to define. I suspect that at the level of the things themselves, nothing is merely random, for reasons I think obvious (yes?). — tim wood

I'm not sure. Intuitively it might seem so, but this is a domain that is far far away from that where our intuitions were formed. God may or may not ultimately play dice with the universe, how can we say?

I'm not sure. Intuitively it might seem so, but this is a domain that is far far away from that where our intuitions were formed. God may or may not ultimately play dice with the universe, how can we say? — hypericin

Suppose instead of God we have Ged. Ged is a postdoc in a ten dimensional universe who is researching the possibility of intelligence evolving in a three dimensional universe. So Ged sets up a Monte Carlo simulation of a three dimensional universe in order to explore the possibility space. Voila, here we are in the multiple worlds of Ged's simulation. :gasp:

As to cause, one of the basic presuppositions of Newtonian science, Newton held that some things were caused and some things were due to the operation of law — tim wood

What you propose here is a distinction between things which occur because they are caused, and things which occur because there is a law operating. This places "things which are occurring because there is a law operating" into a separate category from "things which are occurring because there is a cause". The problem with this proposed separation is the problem of induction which I pointed to already. As Hume demonstrated, these "laws" are inductive, and induction does not provide the necessity required for that category "things which are occurring because there is a law operating", to completely explain any activity.

In simple terms, "there is a law operating" is insufficient to account for the occurrence of things which are said to be "due to" the operation of the law, because the relationship between these two, the occurrence of things and the law, is not one of necessity. That was Hume's point, "law" is an inductive conclusion, and induction cannot ensure that every occurrence will be according to that law. This is why Newton who was trained through Church run institutions, in the traditional manner, supported his laws with "the Will of God". Because "the operation of law" on its own, is insufficient to necessitate any contingent occurrence, the Will of God is needed to underly "law" as substance. You remove "the Will of God" from your representation, but then it does not correctly portray what Newton believed. Newton believed that "the operation of law" required the Will of God. So things which "were due to the operation of law" were understood by Newton to also be due to the Will of God.

I think you need to take a good look at the nature of "contingency", "contingent events". Suppose there is an apple hanging on a tree, and then the apple falls. You'd be inclined to say that when the apple is falling, the falling is due to the operation of law. However, prior to falling, the apple was hanging. And to transition from hanging to falling requires a cause, a bird pecked it, the stem rooted, whatever. Now, you ought to be able to see that "the operation of law" is insufficient as an explanation for any contingent event because a cause is still required at the boundary, which marks the temporal beginning of any event which occurs according to the operation of law.

So we might take a bigger event with a much longer temporal duration, than the falling apple, like the orbiting of the earth around the sun. You'd say that activity is due to the operation of law. However, just like the falling apple, this event is not eternal, it must have a temporal beginning, a cause. That every event such as this requires a cause for its existence, and cannot be explained simply as "due to the operation of law", is the reason why we call them "contingent". Even if the event is according to, or consistent with, a law, it still requires a cause, and at this point necessity was lacking, hence it is contingent. The same principle holds for quantum events of extremely short duration. Any occurrence is contingent, and requires a cause, it cannot simply be said to be due to the operation of law. This implies a very large number of causes in a very short period of time, to account for the reality of all these contingent events.

But you it seems would take a bit of snake, and of newt and frog and bat and dog, and some other ingredients, and boil up a potion that you would call knowledge, but in fact is nonsense or worse. So, for any of your "conclusions" in your posts, never mind all your qualifications and variant perspectives, how do you know? — tim wood

I have no idea what you are talking about here. I didn't talk about snakes, newts, or frogs, that's all in your imagination. And so is your assessment that what I said is "nonsense or worse". Furthermore, your question here is incoherent, you ask me to tell you how I know, without reference to my qualifications.

I'm afraid your source is not very good. It seems to be mistaking the skin effect which is applicable to AC signals, for a general rule about electrical conduction.

In either the AC or DC case, electrical current travels through the conductor. That link provides some explanation as to why in the AC case the conduction of current becomes more and more confined to the outermost portions of the conductor as the frequency of the AC signal increases. — wonderer1

Your assertion is not very convincing wonderer1. I've read a fair bit of material authored by Richard Feynman, much is available on the net. And, he is very explicit in saying that the flow of current is not in the body of the conducting material, because the electrons are freed from the atoms, and the flow is therefore in the field.

Your assertion is not very convincing wonderer1. I've read a fair bit of material authored by Richard Feynman, much is available on the net. And, he is very explicit in saying that the flow of current is not in the body of the conducting material, because the electrons are freed from the atoms, and the flow is therefore in the field — Metaphysician Undercover

It's not clear to me what you have in mind with "because the electrons are freed from the atoms". Are you imagining these free electrons as being outside the body of the conducting material, and that the movement of electrons inside the body of the conductor does not play a role in the propagation of energy through the fields?

On your view, why does it matter what material the conductor is composed of, or what the cross sectional area of the conductor is?

...