Why Quantum?

Thomas Ray

" ... seemingly you have no idea what physical phenomenon might be compactly symbolized by a number in a physics mathematical equation."

E = mc^2

"Numbers are a common everyday thing. If a view of reality is not able to explain numbers, then perhaps it is too superficial, or just plain wrong."

You have a quite innocent view of mathematics, of which 'number' is but a semantic element. What do you mean by number? Counting numbers? Rational numbers? Transcendental numbers? Complex numbers? R, C, O, H?

"Re your belief that reality is 100% deterministic: even Joy Christian wouldn't claim he had evidence that the time and space parameters for every individual particle outcome are predictable beforehand."

He does, however, have the measurement framework for a theory with potential to explain all quantum correlations. Do you understand what that means?

Lorraine Ford

Thomas,

There is clearly no evidence that reality is 100% deterministic/classical: there are only theories and proposals for experiments that might result in such evidence, and unquestionably these experiments must be performed. However I think that there will be no such evidence: "spooky action at a distance" and other seemingly strange quantum mechanical outcomes are the true nature of reality. I think that these outcomes will never be tamed, but they will eventually have a better explanation. In any case, I will be interested to see the results of Jon Barrett and Matt Leifer's work (and hopefully Joy Christian will someday test his theory via experiment).

Re numbers:

The numbers found when nature is measured are some sort of ratio relating to the "measuring sticks" used. There are seemingly no questions about that aspect of these numbers.

If reality is 100% deterministic, the above numbers are seemingly ultimately derived from laws-of-nature and initial conditions. Law-of-nature relationships are represented by equations which may contain numbers e.g. a form of the Einstein field equations contains the numbers 2 and 8, and also the non-algebraic number pi. Initial conditions are represented by a number assigned to each parameter/category in the equations.

If reality is not 100% deterministic, then one implementation of this might consist of windows of opportunity where new information is injected into the system (by subjects), representable as numbers assigned to parameters/categories of information. These numbers are not derived from any laws-of-nature, and they are like a resetting of an initial condition for that parameter.

So what is the physical reality behind these two types of "initial condition" numbers, and what is the physical reality behind numbers like pi?

Lorraine

Thomas Ray

Hey, Lorraine, I'm all for you believing whatever you wish. I'm just trying to give you some facts to help inform your opinion.

You really need to know the difference between determinism and probabilism:

Determinism doesn't mean that every event can be predicted, and probabilism doesn't mean that no events can be predicted. This, however, has absolutely nothing to do with your idea of the role that numbers play, or don't play, in science.

You ask, "So what is the physical reality behind these two types of 'initial condition' numbers, and what is the physical reality behind numbers like pi?"

None. Numbers don't have physical reality. No pi in the sky.

Robert McEachern

Peter,

I agree. "the theory which they established aimed only to describe systematically the response of the apparatus".

Physicists could learn a lot about the nature of information and entropy, if they would study modern communication systems, starting with techniques such as Decision Feedback Equalization. Such techniques are the means by which modern communications systems remove "the response of the apparatus" as well as "interfering information, coming from sources of no interest", leaving behind only the information from the source of interest. This, and this alone, is what has made it possible to, for the first time in history, reliably recover information, at rates very near the Shannon Limit. One cannot get any better than that.

Rob McEachern

Robert McEachern

Even if the laws of physics are 100% deterministic, that does not mean that reality is. Deterministic laws are a necessary, but not sufficient condition, for reality to be deterministic.

In order for reality to be deterministic, all the initial conditions (positions, momentums etc.) must also be deterministic (pseudo random, rather than random). There is no evidence that that is the case. Indeed, the existence of free-will provides a good piece of evidence that it is not the case.

Rob McEachern

[deleted]

Rob,

DFE means: "the distortion on a current pulse that was caused by previous pulses is subtracted". I see a main problem of theorists like Tom and many physicists already in their lacking readiness to accept that the distinction between earlier and later is more fundamental than their trust in a mathematically constructed world. We EEs don't operate with undirected arrows between boxes that symbolize transfer functions while theorists like Wheeler admit the wheel of history rotating back.

That's why I question Minkowski's spacetime and the necessity to integrate over future time too when analyzing past data.

Eckard Blumschein

Lorraine Ford

Thomas,

What on earth is up with you? It's very obvious that, because of complexity, "Determinism doesn't mean that every event can be predicted"!! However, with the physical outcomes of quantum events, the question is whether the probabilistic outcomes are due to determinism+complexity or whether something else is happening. For close to 100 years physics has been struggling with this issue, because presumably if "something else is happening", it might mean that a different nature of reality would have to be posited.

Re numbers: I'm surprised that you have never noticed that THERE REALLY IS an issue with numbers.

Lorraine

Robert McEachern

Eckard,

You have hit one of the big nails, squarely on its head; "the necessity to integrate over future time too when analyzing past data."

I have pointed-out the problem with this previously, in the mathematical techniques at the foundation of QM, namely the use of Fourier Transforms, that integrate over all of time. How can one integrate over all of time, if one does not know the future?

Well, one can indeed know the future, for systems devoid of information, the very systems at the heart of classical physics. It is easy to predict the future of a conserved (constant) quantity, and it is easy to predict the future of a perfectly periodic function (idealized orbits). So, in those cases, one can indeed integrate over the future values, by integrating over the predictions.

Unfortunately, this does not work for unpredictable, high-information-content phenomenon, such as human observers. Unwittingly assuming that it does is THE problem. But this fact is not apparent in the Fourier transform formulation, and, consequently, has yet to be appreciated as a central problem in the mathematical formulation of QM, when it attempts to make claims about how observers behave and impact observable results..

Rob McEachern

Lawrence Crowell

Why quantum mechancs? We really do not know. As I have been studying this it appears that quantum mechanics is really a logical system of gates where there are certain topological properties to the lattice operations that deviate from Boolean logic. The two slit experiment is a sort of topological problem with loops that are not contractible to a point. There is homotopy associated with this. Well then why this? Why could not the foundations be and L^4 measure space instead of L^2, or why could it not have been ... , instead of this? The questions have no conceivable answer.

Quantum mechanics is completely deterministic as it is. Quantum mechanics predicts the evolution of probability amplitudes that sum into a wave function or state vector with complete determinism. That quantum mechanics is unitary is equivalent to saying it is deterministic. The probabilities emerge when one makes a measurement, for the modulus square of those amplitudes give the probability of a certain outcome. This is the bit that is not deterministic --- the measurement process. This forms the basis of the so called measurement problem.

I maintain that a quantum outcome is not objective, but is rather subjective. From the perspective of the Everett Many Worlds Interpretation (MWI) a measurement outcome is a splitting of the world according to the amplitudes of the system. The reservoir of states in the measurement process form an eigenbasis corresponding to the entanglement with the system measured. This in a nutshell is the so called einselection mechanism, which is just a massive entanglement process. We can then tell how the outcomes emerge as classical-like probabilities. We can't however determine which outcome actually obtains. In a subjective perspective the observer is carried off into the various split worlds, and our conscious world line simply takes along one outcome. Consciousness is an epiphenomenon that generates this illusion. The illusion is carried off along the other eigenbranches of the world, but our particular conscious narrative does not include them. These are included on other conscious narratives or world lines.

Why quantum mechanics exists is somehow tied into the question of what is the relationship between mathematics and physics. Tegmark has a very speculative conjecture about this, but I am rather skeptical. I am not sure how one can determine if mathematics is an ontological aspect of physics. There is no mathematical proof of it, nor is there a prospect for some empirical verification of it. The idea is permanently a metaphysical conjecture that is hopelessly outside of both science and mathematics. The same of course holds for the converse of this which is for a Platonic reality or mathematics as an objective system outside of physical reality. This matter is extended further if consciousness is included as something fundamental. No matter which take you have on this the question or proposed ideas are metaphysical. So far there does not exist a decision procedure system for metaphysics.

In the end we are left with Garrison Keillor's take on this as "life's persistent questions." --- " In a city that knows how to keep its secrets, at the 12th floor of the Atlas building one man searches for answers to life's persistent questions; Guy Noir, private eye."

Jason Wolfe

Isn't it much simpler just to say that wave-functions are real things, and that they have energy states and momentum states? That way you don't have to split the universe into an infinite number of branches to represent the eigenstates. Isn't it easier just to say that wave-functions exist?

Jason Wolfe

As fun as a many world interpretation might be to some people, it would flagrantly violate conservation of energy if every universe in the branch is real and solid. For that reason, the MWI might be literally impossible.

In contrast, if wave-functions are assumed to be real things, then there could be this nebulous aether of wave-functions that is completely undetectable, unpredictable and mysterious. Physicists will hate it. But it being very subtle, it also want cause any big problems for physicists to have to explain.

Lawrence Crowell

Ray,

How can wave functions be real, when they are represented as complex valued functions. They are not even mathematically real.

The eigenvalues of QM are determined by Hermitean matrices or operators. These eigenvalues are then by definition real c-numbers that correspond to things measured.

In MWI the amount of mass-energy is constant. Each eigen-branched world is weighted by a probability and the Born rule permits a conservation of mass-energy. This is the case even though there is the appearance of being along only one world and not many.

Lorraine Ford

Lawrence,

Re "The two slit experiment" (Jun. 21, 2014 @ 21:52 GMT): As you say, "when one makes a measurement...the modulus square of those amplitudes give the PROBABILITY of a certain outcome". Quantum mechanics gives very definite PROBABILITIES for INDIVIDUAL outcomes for these particles. So what is definite about reality is its possibility/probability: possibility from the point of view of the particle/subject, probability from the point of view of the observer. So claiming that the situation is "completely deterministic" is to misrepresent things.

You actually admit to the possibilities inherent in reality when you resort to the "Everett Many Worlds Interpretation", completely ignoring the Ockham's Razor principle. So naturally, you conclude by taking a mysterian position on the nature of reality.

You are wrong about consciousness being an "epiphenomenon that generates this illusion". Subjective experience/consciousness is not separate from information about reality: I contend that at the level of a particle, this basic-level information is of mass, charge and law-of-nature relationship. This information is essential to the functioning of reality: consciousness is essential to the functioning of reality.

Rather than giving up and taking a mysterian position, surely, the solution is to free up a little: maybe nature is not quite the tame mechanism that you envisage.

Lorraine

[deleted]

I still find the MWI interpretation of quantum mechanics to be impossible. You are asking me to believe that every time a new eigenstate appears, a new universe (which has an energy content of hundreds of billions of galaxies) just pops into existence. It does so without us even noticing it. It violates conservation of energy flagrantly. Not to mention that the information content of an entire universe has to be duplicated and moved away faster than light so that nobody notices. Physicists believe that, but are shocked and horrified at the idea that the wave-function is a real thing that is perhaps impossible to detect and is very mysterious. Why wouldn't that be the preferred interpretation?

[deleted]

LC,

I would like to learn rather than claiming to be correct. While I understand that and why Hermitian matrices are real-valued, and I very much appreciate your view, I am not sure what you meant with real c-numbers. Did you mean the real parts of complex numbers?

Incidentally, iIrc, Gauss wrote that he regrets that imaginary numbers are called imaginary. He meant that they are quite normal numbers, and his attitude did perhaps influence the further development of mathematics as well as of physics. Gauss correctly argued that negative numbers are justified if there exists something exactly opposite that compensates a positive measure. Dedekind and Riemann were pupils of Gauss. Georg Cantor added naivety ans charisma to their detour from Euclid's and Galileo's rationality.

As a teacher of EE, I operated for more than four decades with imaginary items. However, I was always aware that they are just mathematical tools as to describe something real.

Already Leibniz called the infinites and the infinitesimals well-founded fictions with a fundamentum in re as also is i. I conclude: he did not yet understand that every number is something ideal.

Eckard

[deleted]

Rob, LC,

I guess Eddington was correct when stating: "experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation."

Maybe, the recently claimed at Havard evidence for the BB was premature? Maybe, at least a few of the unwelcome argument I uttered aren't unfounded? My primary concern is to possibly reveal very basic mistakes affecting the relationship between mathematics and physics.

Yes Rob, application of Fourier transformation is to blame.

"How can one integrate over all of time, if one does not know the future?" Heaviside's analytical continuation cheats us: The mirrored past is similar to but essentially different from the open future. I beg for getting aware of what we are doing.

Yes LC, "That quantum mechanics is unitary is equivalent to saying it is deterministic". I see the property to be unitary closely related to the likewise unphysical ideal property to be infinite. While a point, a line, the number pi, etc. are strictly speaking just ideals they are nonetheless common prectice as to describe physical systems. Scruples a la Hjelmslev are unfounded. Moreover, history shows that even slightly dirty mathematics adopted from Leibniz, Cauchy, Dedekind, and Heaviside proved utterly useful. Quantum theories obviously led to valuable applications in contrast to SR which merely created paradoxes. Maybe, some oddities that occur with quantum theories will vanish when we accept that the real-valued cosine transformation may in principle fit better than the complex Fourier transformation.

Eckard Blumschein

[deleted]

The second Law of Thermodynamics holds in a CLOSED system, which does not necessitate that universally spacetime is itself closed. Given the irrationality of pi, if we accept our mathematics to be true enough to reality, it is quite acceptable to conjecture that the only differernce between time and space to be that deficit of radial length resulting from the circumference of a sphere never quite being exactly proportional to any radii constructed to ascertain that a change in volume is physically uniform. If the elusive 'Quantum' realistically exists, it might be found in that relative difference. Energy could then be the creative result of such a physically coherent, yet distinct stress of spatial difference and the relative covariance would be the source of a continuous sustaining creation of energy. This is simply a matter of treating Energy rather than Time as emergent. It is a long way from the laboratory of Lavoisier in yesteryear, to the frontier of inflationary cosmology tomorrow. Bye, now. jrc

Jason Wolfe

Please forgive me for saying the obvious, but some of these explanations of reality sound like a mathematical snowstorm that doesn't actually mean anything. The best explanation for everything that we observe, the quantum fields, the Higgs fields, the encounters with ghosts, is that the quantum vacuum is made of wave-functions that really do exist in some ethereal way, and that the ghosts that people witness are probably real things.

Wave functions are real things!!! That is the simplest and best explanation for quantum mechanics.

Jason Wolfe

I'm not the only one who thinks that wave functions are real things.

http://arstechnica.com/science/2011/11/the-insanely-weird-quantum-wave-function-might-be-real-after-all/

Lawrence Crowell

I am not going to engage in too much discussion on "reality" from a metaphysical perspective, where terms like reify and ontology and the like come into play. Wave functions though are not real in a strict sense of having real valued measurable properties. If one wants to engage in metaphysical conjectures about reality other than this rather operational one, then fine. I just tend not to take these that seriously.

Jason Wolfe

I think that attitude is blocking the physics community from exploring a whole area of theoretical physics that could describe parts of reality that you are all uncomfortable with. For instance, I can explain the physics of a ghost. Let me show you. Virtual photons make electric and magnetic fields work. If a ghost can get access to the virtual photons, if it has great skill it can create a potential energy V(r,t) without using charged particles. If, as I have stated, wave-functions are real things even if they're not measurable directly, then a wave-function will come into existence by virtue of the time dependent Schrodinger equation. This wave-function will have energy states and momentum states that the ghost has to fill with energy (by creating cold spots, siphoning from batteries or from people). Then it can use that energy to move objects, radiate photons that look like scary red eyes, shove people down stairs and do all the spooky poltergeist phenomena.

Can anyone tell me the specific reason for why this kind of a ghost would contradict known physics?

[deleted]

Jason,

"Wave functions are real things"

I tend to agree, energetically of course. jrc

Jason Wolfe

John, you're a radical! lol Watch out! The idea that wave-functions are real things is heresy as far as the physics community is concerned.

Jason Wolfe

I can't help but think that if a ghost is going to produce some phenomena, it has to create an equivalent wave-function/quantum field. To do so, it has to generate the appropriate V(x,y,z,t) in order to get a psi-wave-function that can emit red photons from the eyes (for the glowing red eyes appearance), or appropriate momentum states so that the ghost can properly shove somebody. I'm just using an educated guess, but a spirit is something feels and experiences. To that end, maybe the ghost/spirit has to feel or experience the V(x,y,z,t) that it generates; maybe it feels it as pain or discomfort. But when it doe gnereate a wave-function with energy and momentum states, then it has to obtain energy from somewhere.

Jason Wolfe

By the way, I'm not too interested in philosophy either. I want to understand how observables relate to physics. If someone is claiming to see something that violates physics, I want to know "how" it violates known physics. Physicist "scoffing" at paranormal phenomena is shackling humanity to the dark ages.

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