The Rovelli Point of Wrong Turn

[Farsight]

The crazy things one wants people to believe in quantum theory by denying any ontology to the wavefunction is analogous to trying to do Maxwell theory without introducing the notion of electromagnetic field.

Sounds good to me vanesch. But where does that leave particle physics?

 

[Mike2]

Ontology is nothing else but a simplifying hypothesis that helps us organize our experiences, and so, within quantum theory, the wavefunction plays such a central role that it must be ontologically accepted, until we may have a better (and different) theory.

The trouble is that the wavefunction is an ontological contradiction of terms: the square root of the probability that something might be here or there? Can we say that a probability is "real"? We say it is "real" when we measure it to be the case, but probabilities themselves are only an abstract thing that by difinition is not real in itself. But this sounds like a pretty old argument.

The best we can probably know is that there is a certain emount of information associated with things, even at the Plank scale. Then if we can connect geometry with the functions that tell us how much information is involved, then we might be able to develop an ontology associated with that geometry. We will never actually see the geometric shapes at that scale, but we may be able to gather the information stored in those objects.

 

[Farsight]

If the wavefunction is what's really there, and especially if we're talking about geometry, the moot question is: what objects?

 

[Dcase]

Logarithmic Spirals and spinors / twistors

This is a speculative answer:

Logarithmic Spirals and helices as geodesics and [with loops] as complex harmonic oscillators.

The imaginary unit may be responsible for the natural occurrence of Logarithmic Spirals [as in Nautilus] and vorteces [water drainage, various cyclones, solar system Parker‘s spiral and barred spiral galaxies] through the transcendental numbers Pi and e and the invisible but extant number i.

The "invisible" or "imaginary" object may be the "invisible" or "imaginary" elliptical locus in multiple body problems.

David Hestenes wrote the ‘The Kinematic Origin of Complex Wave Functions’ discussing Dirac and Schroedinger theories.
He describes circular and helical Zitterbewegung and trajectory of the electron, relating them to the “complex phase factor in the complex function” yielding a physical origin for these statistical properties..
[Hestenes like many uses h-bar which does simplify numeric calculations. However h better identifies the eccentricity.]
http://modelingnts.la.asu.edu/pdf/Kinematic.pdf

Caspar Wessel basically proved the existence of the ‘imaginary unit” in 1797. This entity is likely more invisible than imaginary and not a simply a mathematical construct.
‘An Imaginary Tale: The Story of i [the square root of minus one]’ by Paul J Nahin (Hardcover - 24 August 1998)

Consider this applet illustration from MathWorld, with the sun at one locus and nothing at the other locus except a calculation with respect to the influence of a large upon a small celestial body.
http://mathworld.wolfram.com/Ellipse.html

Logarithmic Spirals
a - MathWorld ‘Mice Problem’ applet
http://mathworld.wolfram.com/MiceProblem.html

b - Hermann Riecke and Alex Roxin in their ‘Rotating Convection in an Anisotropic System’ features images. http://www.esam.northwestern.edu/~riecke/research/Modrot/research_klias.htm

Other images:
a - NASA Cosmicopia, The Heliosphere, The Sun's Magnetic Field, the Parker spiral
http://helios.gsfc.nasa.gov/solarmag.html

b - NASA Astronomy Picture of the Day [Spiral Galaxy M83]
http://antwrp.gsfc.nasa.gov/apod/ap950912.html

 

[Farsight]

Spirals, vortexes, loops...

https://www.physicsforums.com/showthread.php?t=125354

...And I've got some reading to do.

 

[OwlHoot]

I'm not convinced a wrong turn has been made. I think theoretical physicists are, in their various and most likely equally sound ways, struggling with various ramifications of more fundamental and probably embarrasingly simple principles, rather as a number theorist might make heavy weather of some investigation of a polynomial before noticing that it could be factorized and that considering the irreducible factors makes the problem more amenable and perhaps even trivial, or some alien trying to analyze a chess game in its advanced stages without knowing all the basic moves, or even being aware that there is a set of basic moves.

If this is correct then the basic principles should eventually become evident almost inevitably by a process of working backwards and elimination, taking the intersection and common features of various plausible and consistent theories, rather as the basic principle of debugging software is that once sufficient information is available then the reason for the bug becomes obvious.

 

[Chronos]

I like the chess analogy. I think is safe to say we do not know all the rules of the physics game so the possible outcomes from a given set of initial conditions are often devishly hard to predict. Trying to derive them through reverse engineering is probably no less a challenge than to devine the pieces and location in a chess game say 10 moves prior to the existing position. There are, of course, numerous possible prior chess configurations [think of them as initial conditions] that could lead to the same end position - which sounds a lot like QT. BTW, in the chess landscape all of the possible prior positions were played.

I think quantum theory is the problem child, mostly because we seem unable to reconcile it with general relativity. GR is an elegant theory that emerges from a simple, underlying theme and has unparalleled predictive power, at least at the macroscopic level. QT, while spectacularly successful in its own right, often behaves erratically and the rule book has been regularly appended to accommodate the exceptions. To me, this signals that QT is not a complete theory - the underlying theme that connects all the dots has not been derived.

 

[vanesch]

The trouble is that the wavefunction is an ontological contradiction of terms: the square root of the probability that something might be here or there? Can we say that a probability is "real"?

If you view the wavefunction as real, you do not see it of course as a "square root of probability" but as a physical entity, in the same way as the spacetime manifold is seen as a physical entity in general relativity. In the same way as one could say that the classical electric field is a kind of "square root of probability" for a photon detector to click. This is not the case: the field is really there, its square is an intensity, and it now happens that a photodetector has a clicking rate proportional to this intensity. But it is not because we can derive a probability from the classical electric field, that the electric field is somehow "the square root of probability" and hence void of physical meaning.

 

[vanesch]

I think quantum theory is the problem child, mostly because we seem unable to reconcile it with general relativity. GR is an elegant theory that emerges from a simple, underlying theme and has unparalleled predictive power, at least at the macroscopic level. QT, while spectacularly successful in its own right, often behaves erratically and the rule book has been regularly appended to accommodate the exceptions. To me, this signals that QT is not a complete theory - the underlying theme that connects all the dots has not been derived.

Well, it is not entirely true that quantum theory is not build upon some simple principles. It has: it is the superposition principle. The problem with quantum theory is that it allows for a vast variety of possible models: you are entirely free to fix your model, as long as you respect the basic postulates. One model is the one of non-relativistic point particles. When you apply the principles of quantum theory to it, you obtain non-relativistic quantum theory. Another model is the one of relativistic fields over Minkowski space. When you apply the principles of quantum theory to it, you get QFT. Yet another model is the one of relativistic one-dimensional objects in Minkowski space. When you do so, you get string theory. All these are just different models to which the rules of quantum theory are applied, but these rules haven't really changed.

Of course, GR is vastly simpler and more elegant - when you limit yourself to 4-dim gravity. But we know that there is more to the world than that, and then you have to introduce auxilliary fields with their own, arbitrary dynamics too.

 

[Chronos]

I entirely agree with your points, Vanesch. The bone I have to pick is QT does not accommodate time. QT works well, and often superbly well under many circumstances, but without a time constraint, it looks suspiciously unphysical.

 

[Mike2]

If you view the wavefunction as real, you do not see it of course as a "square root of probability" but as a physical entity, in the same way as the spacetime manifold is seen as a physical entity in general relativity. In the same way as one could say that the classical electric field is a kind of "square root of probability" for a photon detector to click. This is not the case: the field is really there, its square is an intensity, and it now happens that a photodetector has a clicking rate proportional to this intensity. But it is not because we can derive a probability from the classical electric field, that the electric field is somehow "the square root of probability" and hence void of physical meaning.

When they say "probability" that something might exist or be the case, they are clearly making a distinction between existence/reality and what could have been the alternative. A probability in itself does not exist.

And even if it did, then a probability only exists if the imaginary complex wavefunction also exists, since the probability is equal to the wave function times the complex conjugate of a wavefunction. Again it is a contradiction of terms to say that a purely complex number is real.

All we really have is just an engineering approximation used to fit the data to some curve or another. We don't really know WHY the math is the way it is. The fact that we are now trying to reconcile the math of QM to GR is also an indication that we took a wrong turn sometime early in the process.

 

[vanesch]

We don't really know WHY the math is the way it is.

We never knew that, and we will never know that.