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originally posted by: delbertlarson
a reply to: mbkennel

Lots to respond to again. Here are some thoughts:

Otherwise, if they are both quantum particles, then this isn't true---an entangled state is exactly a mutually interacting one of profoundly quantum entities which haven't collapsed, and this phenomenon is experimentally real.

I agree that entangled states complicate things. One reason I focused on the two slit experiment in my comments here is so that we don't have to deal with such complications. That way, I think we can focus on the essence of the confusion, in an attempt to clarify things. My goal here has been to present a philosophical approach that does not involve what I consider to be wild speculations (such as multiple universes or the role of observers) and yet show how things can be at least understood. As stated earlier, it is really relativity that precludes my simple understanding from being accepted, at least for the two slit case. EPR set up a contest between quantum mechanics and relativity, Bell refined the argument, and quantum mechanics won. But rather than setting aside relativity, it was discovered that EPR relied on an assumption of an underlying objective reality, and then objective reality was called into question. Really, it is relativity that should be set aside. Lorentz's theory should be reconsidered.

Relativity is fine----local realism isn't. I think relativity is a more general principle in physics: all true theories are relativistically covariant. Everybody always writes the Lagrangian in the Standard Model or any proposed modifications that way.

Seems reasonable, but do you believe collapse can happen only with transfer of momentum? What about a flavor changing weak interaction? (to pick up on something exotic at random).

In the case where the photon does not transfer momentum to the barrier containing the slits, I maintain that the wave function collapses to the entirety both slit regions. (Provided they were overlapped by the original wave function.)

Is that collapse or just electromagnetism? To be precise, is there a conservation law such that the total probability before and after is the same? I would think that the answer is no; if you pass plane waves through slits in Maxwellian electrodynamics, then a substantial part of the incident electromagnetic energy & momentum is simply absorbed by the closed parts of the wall.

So the collapse occurs to both slit regions even though there has been no momentum transfer in that case. In that case, since momentum transfer would have been required if the photon collapsed anywhere in the remainder of the barrier, the collapse occurs to the complete regions where no momentum transfer is required. I don't know how such a proposal affects your non-linearity arguments. Do your arguments work when a single photon has a wave function in two separated areas? Of course, weak interactions do transfer momentum, for instance in neutron decay, momentum gets transferred from the neutron to the proton, electron and neutrino as a result of the decay.

Does Copenhagen require this?

I don't know that Copenhagen requires an "observer". I do know that Bell spent a lot of time on that idea, and that it was flourishing for a while some decades ago. I felt it was one of those wild speculations I find unappealing. I note that Arbitrageur has pointed out that Heisenberg didn't feel the need for an "observer" so perhaps Copenhagen really doesn't need one.

OK, but it does seem to require an "apparatus", and that "apparatus" somehow has a power to do things, i.e. apply the von Neumann projection operator, that regular quantum mechanical particles do not. That doesn't make sense as a fundamnental theory to me, as there is no such thing as an apparatus that isn't made out of quantum mechanical particles.

Operationally of course, but the philosophical problem is there---if QM is fully linear then you get multiple universes in effect.

I would say there are infinite (or at least a lot) of particles and/or wave functions within one universe, not multiple universes, even in the case of fully linear QM.

Then you get the problem of the wavefunction of the 'apparatus' splitting and the whole universe in major superpositions which is contrary to physical perception---we don't get macroscopic cats half alive and half dead persistently. In fact, the point of quantum computing technology is to maintain those superposed states for as long as possible and increase the timescale to collapse.

And really, philosophically, this may be where you and I depart. If there are no dice, everything is pre-determined and we are merely a conglomeration of wave functions all heading to our fate - we have nothing to say about it. Choice is merely an illusion. Our thoughts - just an illusion. Your and my discussion here - predetermined by some initial conditions established billions of years ago.

sensitive dependence on initial conditions and chaos gives it back in a nominally deterministic universe.

Instead I believe there must be some random aspect to physics - truly random - so that free choice can exist. A non-determinative quantum mechanics collapse mechanism can provide that randomness, and provides for the physical underpinning of what is commonly known as the soul. It makes choice possible.

I find that to be unnecessary. Chaotic determinism when you have decoherence timescales of 10^-22 s, in a Universe with 10^70 particles and far more degrees of freedom, is as good as fundamental random.

As I understand the state of the literature: "quantum decoherence" is now fully accepted among those in the know and gives randomness as thermodynamics. Nonlinearity is not fully accepted, but I think it is the cleanest solution and it gives collapse as physical dynamics, and simulations show that the observable-state-selecting magic of Bohr & Heisenberg & von Neumann's "apparatus" can come out of integrating equations of motion in the QM functional space.

originally posted by: mbkennel

....is fine----local realism isn't.

The reasons you think the concept of local realism being a true fact of reality is not fine, is because;

Motion (and complex, multi layered, multi qualitative, 'particle decay-able' motions at that) is continuous, so every time one attempts to pint point a locality it has already moved/changed/interacted with other moving parts in other ways; and so you say; any pinpointed locality is not real; and thus there can be know comprehension of a local realism;

However, the mistake is made time and time again, by equating what a human can and cannot and does and does not know in its mind, and therefore how reality can and cannot and is and is not unto its continuously true self.

The other reasons you might have a problem with local realism are reasons I outlined in my prior prior post to you; hidden fields, earths motion (which relates to this point, and which might be a point of relativity), and a potential bias to desire (or unbiased belief) the universe to be Gods computer.

If any 'thing' exists at all, it is locally real to itself; the totality of 'things' that exist are locally real to themselves... and to each other... there is only local realism... there is only realism... unless the universe is a simulation.

Now is part of what you mean by local realism like; the fact that I am typing these words right now, and I am pressing buttons, and first they appeared in my head, and when I pressed the buttons, something happens with electrons in logic gates in my computer, and there is a quantitative, qualitative, temporal, spatial difference between all stages of these events, and then when I hit the reply button this will be stored some place else, and there is a physical different between the quantum quanta of method of storage, and sensual result of the meaning of that method of storage, read by the code of this website, to produce these letters on the screen in its spatial way; and so does local realism and non local realism specifically, relate to this concept, or the concept of butterfly effect?


Also does non linearity just refer to the difficulty of comprehending 'what exactly causes what to occur when', like if a million different sized/and massed balls were shot at a common center point, and the balls had different components so that some on contact could turn into different size and mass, and properties (or maybe I can just say different molecules and/or atoms instead of balls?) it would be difficult to tell a linear story (t = time, s = space) of A at tx sy caused B at tx1 sy1 caused C at tx2 sy2 caused D at tx3 sy3 caused E at tx4 sy4

Instead its like relative cluster of particle 1,5,7 slightly caused x, to cluster 4,8,2 which was slightly being caused by force z, and cluster 978,686 which was caused etc...

Is non linearity the difficult of parsing chicken and eggs from many particles with many motions and many forces under the conditions of the difficulty of comprehending the true initial state of any of them and the measurement problem of watching them each at every moment as they go?

originally posted by: joelr

I think the Moon moving away is just part of what's going on with gravity and energy transference rather than expansion.

I thought for a second that if space-time is expanding then it should have some affect on local gravitational dynamics. Effect of gravity should differ from Newton's only in a way that any local orbit calculation should include Hubble figure, no? (expansion factor)


cheers))

a reply to: Arbitrageur

The size of the universe is either finite or infinite, we don't know which. If it's infinite the question doesn't make any sense, and if it's finite, we don't know and probably will never know because we can only see a portion of the universe called the observable universe which doesn't appear to contain any answer to that question.

Infinite cosmos creates more questions than finite. If I think of matter as some sort of a process resembling condensation phenomenon then the system has to be closed or pushing some resistant 'non-universe' realm.

a reply to: Arbitrageur

The answer should have said "recessional velocities of galaxies closer to Earth are smaller" not "Spacetime expands slowly on a local scale". Since the most recent observations are closest to Earth and the expansion of the universe is accelerating, spacetime doesn't expand more slowly on a local scale, just the opposite, though it's really viewed by cosmologists as a time scale rather than a distance scale, which happen to coincide from our viewing point on Earth.

Recessional velocities of galaxies close to Earth are smaller? Due to time scale rather than distance scale. Please elaborate if you could.

a reply to: delbertlarson

not sure and wanted to ask, why there is even a discussion of what a wave collapse means?

thanks.

a reply to: greenreflections


In a wave collapse, situation couldn't it be called instead "information delivery" The wave becomes a photon, but the collapse occurs in "linear time", which is a construct of consciousness used to explain a working model of the Universe. The wave might never have collapsed, as its always outside of linear time travelling at the speed of light.

Tiny remark as to if it takes human mind to collapse the wave state to become a reality.

I think that it is too much of a processing load for every individual mind to collapse incoming environment wave functions to set complete picture of surroundings with our senses. I mean, imagine work load each individual person has to create (collapse to the point of coherence) each incoming wave cocktail.

No. Too much work for a brain (mind). Here I think that physics already happened before I see the surroundings where my mind is fed with live stream of events that are materializing literally before my eyes. The brain only captures given visual and dedicated to the task of interpretation.


thanks board!

originally posted by: greenreflections
Recessional velocities of galaxies close to Earth are smaller? Due to time scale rather than distance scale. Please elaborate if you could.

This is the graph I posted on p285, made by Edwin Hubble when he created "Hubble's Law":

Hubble's Law


If you move left on the horizontal sale of distance toward Earth, the observations of recessional velocities of galaxies on the vertical scale are smaller.

The reason it's not only a distance scale but also a time scale on the horizontal axis is because of the speed of light. Galaxies 10 million light years away appear as they were 10 million years ago, while galaxies 20 million light years away appear as they were 20 million years ago, and so on. Thus as we observe at greater distances we are looking further back in time. The "Pillars of creation" in my avatar are what the Hubble telescope sees today, but if you could travel to that location instantly by some kind of magic what you would likely see is that structure doesn't exist right now. The image Hubble sees is from thousands of years ago and it's since likely been destroyed from a shock wave we know of, headed that way.

originally posted by: greenreflections
Tiny remark as to if it takes human mind to collapse the wave state to become a reality.

I think that it is too much of a processing load for every individual mind to collapse incoming environment wave functions to set complete picture of surroundings with our senses. I mean, imagine work load each individual person has to create (collapse to the point of coherence) each incoming wave cocktail.

No. Too much work for a brain (mind). Here I think that physics already happened before I see the surroundings where my mind is fed with live stream of events that are materializing literally before my eyes. The brain only captures given visual and dedicated to the task of interpretation.


thanks board!

and besides, we all share same reality!!! How come? It must be mutual and pre conditioned, no?

a reply to: Arbitrageur
does it have anything to do with perspective?

Universe expansion speed localy vs at distance...You speak like true Einstein follower.

originally posted by: greenreflections
a reply to: Arbitrageur
does it have anything to do with perspective?

Interestingly there is one model that suggests that's a possibility, however the model is almost certainly wrong and I don't know of anybody who believes it but some religious types and other anthropocentrically-biased folks might like it:

Mathematicians' Alternate Model of the Universe Explains Away the Need For Dark Energy

Mathematicians Blake Temple and Joel Smoller developed a new theory: Earth sits near the center of an expanding wave that began after the Big Bang. That accelerating expansion could have led to the spread of galaxies as astronomers see them today, but would not itself represent a constant accelerating force. The duo from the University of California-Davis and the University of Michigan talked with other mathematicians and astrophysicists to flesh out their calculations.

Such an alternative vision of our universe has the attraction of only relying on Einstein's equations of general relativity, Seed Magazine explains.

So if Earth is at the center of the universe, that might possibly explain observations without dark energy according to these mathematicians, but most scientists don't think Earth has such a special place in the universe, called the "Copernican Principle". That's based on an extension of the idea that the Sun doesn't revolve around the Earth and neither does the universe.

Universe expansion speed localy vs at distance...You speak like true Einstein follower.

Did you read these papers? It was a major discovery in 1998 and totally unexpected.

arxiv.org...
arxiv.org...

originally posted by: greenreflections
a reply to: delbertlarson

not sure and wanted to ask, why there is even a discussion of what a wave collapse means?

thanks.

Fundamentally, if we assume that wave functions are something real, then wave function collapse is inconsistent with special relativity. That is because the wave function has a finite (non-zero) extent, and it instantaneously collapses upon interaction with another entity, while special relativity is a theory that only allows point-like events in four space. The point-like requirement in special relativity comes about because the concept of "instantaneous" is different depending upon which frame of motion you analyze things from. Hence, actions at a distance are forbidden in special relativity. This fundamental confrontation between special relativity and quantum mechanics has led to many wild speculations concerning wave function collapse in an effort to save the special theory.

It is my view that it is far simpler just to return to Lorentz. There are almost no differences between Lorentz and Einstein mathematically or physically - after all, relativity uses the "Lorentz Equations". The predominant difference between Lorentz and Einstein is philosophical. Is there a preferred frame wherein lengths and times are correct, and clocks and meter sticks deform when they move in that frame? (Lorentz) Or is every frame equivalent, and time and space themselves transform when one observer moves with respect to another? (Einstein) If we go back to the Lorentz approach, simultaneity is well defined (it is the simultaneity of the preferred frame) and actions at a distance, like wave function collapse, present no problem.

Note that we can still have covariance in our equations under a Lorentzian philosophy. The only difference is that since time and space are no longer on equal footings, the equations now represent transformed quantities that need to be related back to their preferred values if we want to deal with the "real" time and space. But all the equations can still be used.

It really isn't that hard to understand, but we need to set the special theory aside.

a reply to: mbkennel

I will be posting my comments on your paper soon, and those comments may help illuminate our difference of opinion further. But before I get to that, I wanted to reply to a couple of points in your previous reply. Also please see my reply above to greenreflections concerning Lorentz vs. Einstein.

Is that collapse or just electromagnetism? To be precise, is there a conservation law such that the total probability before and after is the same? I would think that the answer is no; if you pass plane waves through slits in Maxwellian electrodynamics, then a substantial part of the incident electromagnetic energy & momentum is simply absorbed by the closed parts of the wall.

The answer you think is no, I answer yes - for each individual photon. That is, each photon prior to interacting with the barrier has a size that overlaps both slits and a substantial amount of the barrier. That single photon then collapses either to a single point of the barrier, or to both slit regions.

sensitive dependence on initial conditions and chaos gives it back in a nominally deterministic universe.

Even if it is sensitive, if initial conditions are exact, then determination follows, chaos or no. What chaos enters into the discussion is that we may not be able to measure things well enough to predict things. Chaos tells us that small differences can lead to big result differences so that things look random but in reality they are not random. This then gets us back to fate being predetermined - we just don't know what that fate is, and have no way to tell. But our fate is our fate.

At the end of the day, we either have free will or not. And to have free will we need some form of fundamental randomness that our will can control. In my view, wave function collapse supplies that fundamental randomness.

a reply to: delbertlarson

What chaos enters into the discussion is that we may not be able to measure things well enough to predict things. Chaos tells us that small differences can lead to big result differences so that things look random but in reality they are not random. This then gets us back to fate being predetermined - we just don't know what that fate is, and have no way to tell. But our fate is our fate.

At the end of the day, we either have free will or not. And to have free will we need some form of fundamental randomness that our will can control. In my view, wave function collapse supplies that fundamental randomness.

I agree - in fact, I think I could bring a proof, under the form of a thought experiment.

I once descibed how Time could in theory form loop (this arises naturally if the concept of tachyon is merged with Special Relativity). I described how "paradox waves" solve the Grandfather Paradox - paradoxes actually travel at a finite speed up the axis of Time, making the Present safe from any changes in the Past. But anyway, to the point: such a solution enables Time Loops. Events in which Time repeats itself.

There is a problem though: Time loops would violate Uncertainty Principle. If you make a quantum measurement of a particle once, and Time then repeats itself, then in theory you'd already know the properties of the particle the next time around without even having to measure it - violating the Uncertainty Principle.

Unless Chaos is introduced - at the quantum level.

I call it Heisenberg Evaporation of Time Loops: each time the Loop restarts, particles in the universe get their properties randomized by chaos. So actually your memory of the particle's quantum state in the previous history only has a probability of being representative of the same particle in the new instance. At one point, it is possible that the randomness grows strong enough to break the mechanism of the Time Loop itself - and evaporate the Loop. To make that work, the Universe needs an active force which constantly randomizes particle quantum states in any moments so to make them resistant to foreknowledge - chaos.

a reply to: mbkennel

I enjoyed reading your paper. Here I present some comments.

In section 1, you offer three approaches to wave function collapse. I guess I am uncertain where my third postulate above would fall in those three approaches. (My third postulate is that when momentum is exchanged in an interaction, a state collapses to dx=hbar/dp.) You do mention decoherence, and then refer to it as well as your work as alternatives to the three approaches, so I guess my postulate would perhaps be in the "alternative" category too.

I do not find anything objectionable nor have comments about section 2. Moving on to section 3:

An important property of the measuring instruments is that they have an adequate qualitative change to the properties of the measured system.

I agree. And you state this very well.

Indeed, every measurement process is accompanied by either the creation or annihilation of particles.

I believe the above statement may be a bit misleading. Some measurements may involve the scattering of particles off of other particles, and it may be that nothing is really created nor destroyed in that scattering, at least no real particles need be created nor destroyed. Now if you are defining a particle as both its raw, basic existence AND its momentum, then of course you can say that the first particle was destroyed and the second created, but I think most students would not really call this particle creation and destruction, rather they would just say the particle changed its momentum. Now downstream from the primary scattering interaction our equipment may indeed involve creation of photons to help us see the results, but by then, at least in my way of thinking, any collapse had already occurred previously. (I believe collapse occurred in the original scattering in this example.)

For example, in quantum electrodynamics (QED), the Dirac field and the electromagnetic field are operators

Following the above quote, you discuss the fact that some non-linearities arise, and also that perturbation theory is often resorted to in order to do calculations. When I took classes in this matter back in graduate school, I was a bit horrified. Yes, it all worked. But on more than one occasion there was some "magic" done to get the results. Renormalization theory was essentially the ignoring of some unfortunate infinities, for one. I never had the feeling that it was on a sound footing, even though it has been spectacularly successful computationally. But what is worse, the techniques cannot be used when the coupling gets large, such as for the strong force. And then, by the time we get into Hilbert spaces, and putting complicated Lagrangians into the equations, things get so extremely complex that I feel we're getting away from what physics should be. Now I readily admit that we may need all the complexity, and that it all works, I just think it gets us away from the simplicity that is often the hallmark of great advance. It reminds me of "the music of the spheres" prior to Kepler.

Now, from section 4:

For example, the experiments[19-21]demonstrated the wave properties of fullerenes. In this case, the moving fullerene can emit photons, which can also be registered. In the experiment, with the increasing temperature of the fullerene, the interference pattern gradually disappears when the fullerene emits photons with increasingly shorter wavelength. Finally, when the characteristic wavelength of the photon becomes comparable with the distance between the slits, the interference pattern disappears (Fig. 2). This situation corresponds to the determination of the slit through which the molecule passes.

Note that the above behavior is identical to what I would expect would occur with my Postulate 3, and really is excellent experimental support of Postulate 3. However, since this may not be immediately obvious, let me dwell on it a bit. When the fullerene emits a photon, momentum is exchanged between the fullerene and that photon. Hence, the fullerene wavefunction will collapse to a size of dx=hbar/dp. If that size is large enough to cover both slits, then we will still expect some interference pattern downstream, since a portion of the fullerene can be in each slit in that case. If that size is so small so as to isolate the fullerene to one slit or the other, it will not be able to interfere with itself anymore, since there is no part of itself in the other slit. Of course, and I hope you have understood this all along, even though I have not been explicit, the dx here is not a hard cut-off value. Rather it is just like parameters in all of quantum mechanics. Often wavefunctions have some exponentially falling off tail, and dx here is a parameter that gives the rough size within which lies a majority of the wavefunction. Hence, once the emitted photon has a wavelength just barely small enough to collapse the fullerene to predominantly exclude one of the slits, you will still expect some of the interference to show itself because of an exponential tail. The situation should be continuous, just as you report the experiment shows.

Indeed, for example, the calculations of the energy levels of the hydrogen atom using quantum mechanics provide notably accurate values. QED refines them but by only a small amount, which is not important in many cases (e.g., the Lamb shift of the energy levels)

I agree. I would further note that the hydrogen atom quantum mechanics is beautiful and simple. (This is in marked contrast to the QED analysis.)

In this case, we can work without a complete set of equations (1)-(3) and solve the linear Schrodinger equation because the spectral lines are measured using macroscopic devices (for example, the registration of the spectrum of the hydrogen atom using a spectrometer is a macroscopic process), where the wave function collapse is inevitable because many particles are produced.

In my view, the wave function doesn't need to collapse at all in the hydrogen states - it is already collapsed and almost static. However, we do get radiation emitted as one predominantly stationary state transitions to another. The ground state of hydrogen is just that - a ground state. The wave function for it is static unless disturbed. Now there can be a separate wave function for the position of the hydrogen atom as a whole, but the wave function for the electron and proton within the atom is the static, well defined function given by quantum mechanics. Similarly, its excited states are also given by quantum mechanics. They are close to stable states as well. (Although radiative decay can transition them to a lower energy state in time.) This situation is different from the two slit case where things are dynamic. In the two slit case, we have a wave of very large (comparatively) transverse dimensions that is forced to collapse into much smaller dimensions when it hits the slits, and even smaller dimensions when it hits a wall. The two slit case is one of collapse into available states. The states of hydrogen are already collapsed states, in my view.

I do believe that sections 5 through 7 are reasonably convincing, and I do agree that when we get to macroscopic states that entities are collapsed pretty much all of the time. I believe the momentum in vibrations does the collapse, you argue for particle creation/destruction. Either way, it works.

a reply to: delbertlarson

Did he credit me as the source of his best ideas?

originally posted by: ImaFungi
a reply to: delbertlarson

Did he credit me as the source of his best ideas?

Please elaborate.

originally posted by: Arbitrageur
a reply to: greenreflections
The answer wasn't worded that well and you're also making some additional false assumptions. The answer should have said "recessional velocities of galaxies closer to Earth are smaller" not "Spacetime expands slowly on a local scale". Since the most recent observations are closest to Earth and the expansion of the universe is accelerating, spacetime doesn't expand more slowly on a local scale, just the opposite, though it's really viewed by cosmologists as a time scale rather than a distance scale, which happen to coincide from our viewing point on Earth.

Yes but I was just trying to get across the idea of why expansion can get to such high speeds for very distant objects. I wasn't getting into the new discoveries of expansion speeding up yet.
The Hubble constant doesn't deal with objects far in the past, it deals with how fast expansion would be now. So wouldn't that be a distance scale?