Interpretations of QM

[NTuft]

On 12/31/2022 at 7:29 AM, Genady said:

With so many, how does one pick a favorite?

On 1/1/2023 at 3:59 PM, Genady said:

To better understand this statement, or rather to understand it at all, may I ask if the computer in front of me exists in any meaningful ontological sense?

On 1/1/2023 at 5:08 PM, Genady said:

I am familiar with the models. I just wanted to understand what is

I still don't know.

Maybe I do... Then my answer [...]

 

is, No. This is regardless of waves, particles, strings, [...]

I don't know. I think you've got to catch them all, then try to compare and contrast. Which one did you choose that lead to that question and answer?

 

On 1/1/2023 at 4:21 PM, Lorentz Jr said:

If you take quantum wave equations seriously as indications of what matter really is, your computer exists as a very complicated wave but not as a collection of particles. According to objective-collapse theories, quantized amounts of the wave keep collapsing repeatedly, creating the illusion of solid matter. The various theories differ in how and why the collapses occur.

On 1/2/2023 at 12:31 AM, Lorentz Jr said:

There's a theory of geometric gravity without relativity, and it seems very strange to me that physicists wax philosophical about abandoning cherished misconceptions, while at the same time clinging to the classical ontology of matter as being made of solid entities of one kind or another, in the face of wave-based quantum theories.

It's called a matter wave, I think it's implied to be "... solid... of... kind...". I read your speculations thread. I don't know if you're on about point particles or (more likely) elementary particles, but it's a stretch to go from there to Genady's computer and I'll be a monkey's uncle if it's not a solid by then. I mean that's a marco-molecular structure, composite particles and on into actual chemicals. Thanks for the link here.


Genady doesn't even believe his computer exists ontologically. I'm ontologically uncertain about ontology and I blame 1)Markus Hanke and 2)Loretnz Jr. +1 to TheVat who is on about David Bohm and particles over there. Interpretations of QM->Quantum physics->QFT and of course a treatment for time and gravity so from the end of Relativity:

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The question of the particular field law is secondary in the prceding general considerations. At the present time, the main question is whether a field theory of the kind here contemplated can lead to the goal at all. By this is meant a theory which describes exhustively physical reality, including four-dimensional space, by a field. The present-day generation of physicists is inclined to answer this question in the negative. In conformity with the present form of the quantum theory, it believes that the state of a system cannot be specified directly, but only in an indirect way by a statement of the statistics of the results of measurement attainable on the system. The conviction prevails that the experimentally assured duality of nature (corpuscular and wave structure) can be realised only by such a weakening of the concept of reality. I think that such a far-reaching theoretical renunciation is not for the present justified by our actual knowledge, and that one should not desist from pursuing to the end the path of the relativistic theory.

 

Having reached different conclusions about his computer and although I hold in reserve G.'s ability to speak facetiously and cryptically can it be inferred that we have different QM interpretations that led inexorably on to logically to this result or is it an illogical loosening on someone's part.

 

I request speculation on this unverified claim:

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... gauge fixing can simplify calculations immensely, but becomes progressively harder as the physical model becomes more realistic; its application to quantum field theory is fraught with complications related to renormalization, especially when the computation is continued to higher orders. Historically, the search for logically consistent and computationally tractable gauge fixing procedures, and efforts to demonstrate their equivalence in the face of a bewildering variety of technical difficulties, has been a major driver of mathematical physics from the late nineteenth century to the present.

and clarification of if it is Smolin's Public Lecture: Time Reborn at PI, or what, that is referenced.

[Lorentz Jr]

2 hours ago, NTuft said:

I don't know if you're on about point particles or (more likely) elementary particles, but it's a stretch to go from there to Genady's computer and I'll be a monkey's uncle if it's not a solid by then. I mean that's a marco-molecular structure, composite particles and on into actual chemicals.

• Trillions of neutrinos fly through every person's body every second.
• Electrons as solid particles have no currently observed size, and even quantum field theory models them as waves. And electrons occupy something like 99.9999999 percent of the volume of every atom.

I believe macroscopic "solids" are waves that repel each other. Or maybe they're collections of "wavicles", or whatever you want to call wavelike quanta. It's very puzzling to me, because quantized wavelike entities seem like they would be very hard to implement. I think quantized field interactions might be easier to implement, because they're more localized.

2 hours ago, NTuft said:

can it be inferred that we have different QM interpretations that led inexorably on to logically to this result or is it an illogical loosening on someone's part.

I have my own interpretation of QM. I call it the "Brownian motion" interpretation. It's not exactly based on motion, but it says the quantum uncertainty of (low-dimensional) particle behavior (that people obsess over so much in Bell's inequality) is ultimately derived from the (high-dimensional) structure and deterministic behavior of the vacuum at some very small scale. Larger than the Planck scale, smaller than whatever is the smallest scale of quarks or other forms of matter that has been detected.

Edited January 15, 2023 by Lorentz Jr

[Genady]

5 hours ago, NTuft said:

Which one did you choose that lead to that question and answer?

I'd be glad to try to answer this question if I knew what it refers to. Could it be a complete question here rather than references to bits and pieces of a conversation that occurred 2 weeks ago?

[NTuft]

@Lorentz Jr,
How big is an electron?
To address your second bullet I go to interpret scattering/splitting experiments. The hard, dense nucleus follows from one. Equating  gives the classical electron radius, ~10^-15m, which would be about the same size as the nucleus there. From the Zeeman effect I believe the electron has a magnetic dipole, and the Lamb shift indicates the exchange interaction of electromagnetic force in vacuum. Limiting e rotational speed below c in accounting for the magnetic moment indicates a lower limit on e radius of 10^-12m(). Is that the value from which you make your 99.99% claim? Ostensibly it cannot be confined to space less than that because if it were smaller there'd be enough energy for e creatio ex vacuum: producing a positron-electron to annihilate and have a bonus e. The  limit calculation is modelling the electron as a classical spinning object (with the constraint v<c), but the interpretation is from the exchange interaction. Experiments have put bounds on the electric and magnetic dipole moments:
 

Quote

Laser-cooled polyatomic molecules for improved electron electric dipole moment searches
Experimental probes of the electric dipole moment of the electron (eEDM) provide strong constraints on theories of particle physics beyond the Standard Model (BSM) [1–6]. The most stringent limit on an eEDM has been realized in experiments using a diatomic molecule, ThO, in a 3Δ1 state, limiting the eEDM to < 1.1 × 10⁻²⁹ e cm [7, 8]. This has placed limits on T-violating new physics above the TeV scale [5, 6]. Other work, using HfF+ with the same electronic structure, has confirmed the ACME results at the <1.3 × 10⁻²⁸ e cm level [9].  

² ACME Precision Measurement of the Electron Electric Dipole Moment (EDM)

Towards an Improved Test of the Standard Model’s Most Precise Prediction

The most precise prediction of the SM is the size of the electron magnetic moment μ→e−.
[...]

5. Probe for Electron Substructure
Comparing experiment and theory probes for possible electron substructure at an energy scale, one might only expect from a large accelerator. An electron whose constituents would have mass m∗≫m has a natural size scale, R=ℏ/(m∗c). The simplest analysis of the resulting magnetic moment [21] gives δa∼m/m∗, suggesting that m∗>400,000TeV/c² and R<5×10⁻²⁵ m. This would be an incredible limit, since the largest e+e− collider (LEP) probed for a contact interaction at an E=10.3 TeV [22], with R<(ℏc)/E=2×10⁻²⁰ m.
However, the simplest argument also implies that the first-order contribution to the electron self-energy goes as m∗ [21]. Without heroic fine-tuning (e.g., the bare mass canceling this contribution to produce the small electron mass), some internal symmetry of the electron model must suppress both mass and moment. For example, a chirally invariant model [21], leads to δa∼(m/m∗)2. In this case, m∗>460GeV/c2 and R<4×10−19 m. These are stringent limits to be set by an experiment carried out at 100 mK, although they are not yet at the LEP limits. With a more precise measurement of α, so this was limited only by our experimental uncertainty in a, then we could set a limit m∗>1TeV/c2 and R<2×10⁻¹⁹ m.
6. Comparison to the Muon Magnetic Moment
The electron magnetic moment is measured about 2300 times more accurately than is the moment of its heavier muon sibling [4,23]. Because the electron is stable there is time to isolate one electron, cool it so that it occupies a very small volume within a magnetic field, and to resolve the quantum structure in its cyclotron and spin motions.

From my read this puts the electric dipole moment measurement at 1.1 × 10⁻²⁹ e cm, and "a natural size scale, R<(ℏc)/E=2×10⁻²⁰ m"? So the experimental results read to me as saying a size below the Compton wavelength is possible. Do you really think the size of the electron is the size of the electron wavefunction? Or isn't the wavefunction a description of the probability of finding the electron at a certain position?

@Genady,
It may be that you have a high momentum computer, or rather, that your computer's position is so well known that it's momentum is uncertain. However, I'm not sure that the same laws apply at different scales, and that seems to be the insoluble problem. Perhaps your computer's existence is not dependent on any uncertainty relation, or, there is no reason to be biased by creatio ex minima schemas and disregard macroscale classical experience. It may be a form of causal opacity from the interpretations, because I think it's fine to presume that the various scales were accounted for to work well; i.e. your computer ontologically exists. Or please explain why not.

Edited January 18, 2023 by NTuft
-expanding

[Lorentz Jr]

4 hours ago, NTuft said:

Do you really think the size of the electron is the size of the electron wavefunction?

Yes, I think all matter and radiation are made of waves. I don't believe in particles. I think they're artifacts of classical thinking.

[Genady]

6 hours ago, NTuft said:

Or please explain why not.

Computer is a concept which we (you, me, some other people) use to organize our perceptions of the world. A member of lost Amazonian tribe while finding a computer in the forest would perhaps perceive three blocks rather than one anything, i.e. a big block (monitor), a medium size block (keyboard), and a small block (mouse). And she will be right.

2 hours ago, Lorentz Jr said:

I don't believe in particles. I think they're artifacts of classical thinking.

Same here. Same about waves.

[Mordred]

One of the problems of the particle view is the electron spin taking the diameter that NTuft provided. The electrons angular momentum and that diameter. The electron angular momentum would end up exceeding the speed of light. If I recall the calculation correct it would be roughly 10 times c.

 The field excitation view with the increased radius this isn't the case. 

 I mention this as it's one of the common arguments you will find that is used to support the field excitation view.

 Though certainly not the only argument. 

I should further mention that electron spin is intrinsic. It requires a 720 degree rotation to return to its original state so don't think of particles as little spinning balls.

Edited January 18, 2023 by Mordred

[NTuft]

9 hours ago, Lorentz Jr said:

Yes, I think all matter and radiation are made of waves. I don't believe in particles. I think they're artifacts of classical thinking.

Doesn't the 99.99% volume occupancy by the electron only follow from a dense nucleus of particles? From reading Inside the Proton, the 'Most Complicated Thing You Could Possibly Imagine', there are unknowns, but it seems hard to argue away the explanatory power of particles a la the Standard Model. I need to read "Matter as excitations of the field", as admittedly I don't understand the field views well enough, so know I don't discount your perspective out of hand.

6 hours ago, Genady said:

Computer is a concept which we (you, me, some other people) use to organize our perceptions of the world. A member of lost Amazonian tribe while finding a computer in the forest would perhaps perceive three blocks rather than one anything, i.e. a big block (monitor), a medium size block (keyboard), and a small block (mouse). And she will be right.

...

True, though the object still has an "objective" existence aside from it's functional conception.

4 hours ago, Mordred said:

One of the problems of the particle view is the electron spin taking the diameter that NTuft provided. The electrons angular momentum and that diameter. The electron angular momentum would end up exceeding the speed of light. If I recall the calculation correct it would be roughly 10 times c.

 The field excitation view with the increased radius this isn't the case. 

 I mention this as it's one of the common arguments you will find that is used to support the field excitation view.

 Though certainly not the only argument. 

I should further mention that electron spin is intrinsic. It requires a 720 degree rotation to return to its original state so don't think of particles as little spinning balls.

The field excitation view... From the linked write-up, there are problems resolving the proton's spin, too. It seems to be related to magnetic field interactions, and to my mind electronic spin and nuclear magnetic resonance look to be making use of a classical spinning.. Dirac's belt trick can be done with a belt. What the analogy of the tethered ends would be, I don't know. I doubt that it is classical, unless there's some physical dimensionality that is difficult to conceptualize, and I'm a bit stuck in classical and not sufficiently confused by the quantum picture as I haven't understood it.

[Mordred]

Proton is a bit of a tricky devil as it revolves on the valence quarks two up and one down with a quark sea of indeterminant number of other quarks. Think of it as a quark gluon confined cloud 

[Genady]

3 hours ago, NTuft said:

the object still has an "objective" existence

I think that there is something out there which we perceive as the object. Just like we perceive these patterns of light on the screen as words written in English.

[Lorentz Jr]

On 1/3/2023 at 7:16 AM, Genady said:

Now I understand what you mean by "ontology". I'm not sure it is a common understanding of this word.

From Fashion, Faith, and Fantasy in the New Physics of the Universe

by Roger Penrose

Chapter 2, section 2.12: Quantum Reality

Quote

Are we to regard ψ as actually representing physical reality? ... according to [Copenhagen and other interpretations], ψ is to be regarded as a calculational convenience with no ontological status other than to be part of the state of mind of the experimenter or theoretician ...

[Bohmian mechanics] provides an interesting alternative ontology ... It ... provides a much more clear-cut picture of the "reality" of the world. ... presents two levels of ontology, the weaker of the two being provided by a universal wave function ψ ...

Hah! Penrose uses the word the same way. 😎

Edited January 23, 2023 by Lorentz Jr

[Genady]

4 minutes ago, Lorentz Jr said:

From Fashion, Faith, and Fantasy in the New Physics of the Universe

by Roger Penrose

Chapter 2, section 2.12: Quantum Reality

Hah! Penrose uses the word the same way. 😎

Yep.

[NTuft]

Well... "interpretations of QM", or, what sort of "spin" are they putting on it?

My own bête noire in physics, I'd thought it a mere phantasm, I've found still lurks in the math. I recommend this introductory paper on Geometric Algebra(GA): Oersted Medal Lecture 2002: Reforming the Mathematical Language of Physics, by David Hestenes, Department of Physics and Astronomy Arizona State University  (.pdf, attached)

In the Schrödinger wave equation, in developing the operator formalism I couldn't understand the treatment of the -iħ term; I still don't. I'd seen i was treated differently in matrix mechanics, and read it was regarded as the phase angle of the wave. After Hestenes's initial math work-up, he goes on to demonstrate that -iħ is actually encoding spin.

The GA formalism builds up vector multiplication differently as the geometric product: a sum of a symmetric inner product and an antisymmetric outer product. There is an absence of commutative rule, but left and right distributivity are given seperately, and there is a contraction rule peculiar to GA. The outer, "wedge", product is related to the traditional cross product by a ∧ b = i a × b, and so the geometric product of vectors a and b can be stated as ab = a ·b + i a × b . 

The multivector form, M = α + a + ib + iβ (30), is comprised of a scalar, vector, bivector, and pseudoscalar, so "the Geometric Algebra G₃ is a linear space of dimension 1 + 3 + 3 + 1 = 2³ = 8. The expansion (30) has the formal algebraic structure of a “complex scalar” α + iβ added to a “complex vector” a + ib, but any physical interpretation attributed to this structure hinges on the geometric meaning of i...".

He develops some natural facility for reflections and rotations, which given a normal basis are co-ordinate free, and develops "rotors", which are equatable to quaternions. From my basic understand, a Clifford algebra is a combination of the Grassman algebra and Hamilton's quaternion algebra; Clifford had called it geometric algebra and Hestenes seems to have been devoted to developing this math formalism that Grassman had started.

Quote

This is a good place to summarize with a list of the advantages of the GA approach to rotations, including some to be explained in subsequent Sections:

1. Coordinate-free formulation and computation.
2. Simple algebraic composition.
3. Geometric depiction of rotors as directed arcs.
4. Rotor products depicted as addition of directed arcs.
5. Integration of rotations and reflections in a single method.
6. Efficient parameterizations (see ref.16 for details).
7. Smooth articulation with matrix methods.
8. Rotational kinematics without matrices.

Moreover, the approach generalizes directly to Lorentz transformations, as will be demonstrated in a subsequent paper.

Pg. 23

 

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The point of all this is that GA reduces the set of three vectorial equations (57) to the single rotor equation (55), which is easier to solve and analyze for given  [Ed.:where ,  is te angular(rotational) velocity]. Specific solutions for problems in rigid body mechanics are discussed elsewhere.16 However, the main reason for introducing the classical rotor equation of motion in this lecture is to show its equivalence to equations in quantum mechanics given below.

Pg. 24 Emphasis, clarification added

 

 

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VII. Real Quantum Mechanics

Schroedinger’s version of quantum mechanics requires that the state of an electron be represented by a complex wave function ψ = ψ(x, t), and Born added that the real bilinear function ρ = ψψ^† (70) should be interpreted as a probability density for finding the electron at point x at time t. This mysterious relation between probability and a complex wave

Pg. 26

function has stimulated a veritable orgy of philosophical speculation about the nature of matter and our knowledge of it. Curiously, virtually all philosophizing about the interpretation of quantum mechanics has been based on Schroedinger theory, despite the fact that electrons, like all other fermions, are known to have intrinsic spin. We shall see that that is a serious mistake, for it is only in a theory with electron spin that one can see why the wave function is complex. You may wonder why this fact is not common knowledge. The reason is that the geometric meaning of the wave function lies buried in the standard matrix version of the Pauli theory. We shall exhume it by translating the matrix wave function Ψ into a real spinor ψ in GA where, as we have seen, every  has a geometric meaning. We discover then that the in Schroedinger theory emerges in the real Pauli version as a bivector that is related to spin in an essential way. In other words, we see that geometry dictates that spin is not a mere add-on in quantum mechanics, but an essential feature of fermion wave functions.

[...]

In particular, we find that the spinor wave function operates as a rotor in essentially the same way as rotors in classical mechanics. This suggests that the bilinear dependence of observables on the wave function is not unique to quantum mechanics — it is equally natural in classical mechanics for geometrical reasons. Though the relation of spin to the unit imaginary was first discovered in the Dirac theory,21, 22 it is easiest to see in the Pauli theory. The resulting real spinor wave equation leads to the surprising conclusion that spin was inadvertently incorporated into the original Schroedinger equation in the guise of the distinctive factor ħ. [...]

Pg. 27

 

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Thus, is the eigenvalue of the “spin operator” S. Otherwise said, the factor  in the Pauli matrix equation (75) is a representation of the spin bivector by its eigenvalue. The eigenvalue is imaginary because the spin tensor Sij = −Sji is skewsymmetric. We can conclude, therefore, that spin was originally introduced into quantum mechanics with the factor in the original Schroedinger equation.

Pg. 32

This is identical to the classical expression for the rotational kinetic energy of a rigid body with angular momentum 2s. 16 All this suggests that the rotor U describes continuous kinematics of electron motion rather than a probabilistic combination of spin-up and spin-down states as asserted in conventional Pauli theory. The most surprising thing about the energy expression (104) is that it applies to any solution of the Schroedinger equation, where  . But, according to (102), e1 and e2 are spinning about the spin axis with angular velocity ω, and (104) associates energy with the rotation rate. The big question is, “What is the physical meaning of this spinning?”

Pg. 33

 

There is also the paper Spacetime Physics with Geometric Algebra (.pdf attached), the sequel to the Ørsted medal lecture paper, with Section VIII: Interpretations of Quantum Mechanics.

OerstedMedalLecture.pdf SpacetimePhysics.pdf

Edited February 9, 2023 by NTuft
added last quote

[kba]

On 12/31/2022 at 8:29 PM, Genady said:

With so many, how does one pick a favorite?

Yet new one - "Dynamical gravity" theory which explains QM in atom and for particle's interaction.

No more Dice for God and no more tries for gravity quantumization.

Edited February 14, 2023 by kba

[Genady]

1 hour ago, kba said:

Yet new one - "Dynamical gravity" theory which explains QM in atom and for particle's interaction.

No more Dice for God and no more tries for gravity quantumization.

This thread is about interpretations of the QM, not about other theories. If you want to discuss a theory which is different from QM, start another thread.