View Poll Results: To which interpretation of Q.M. do you subscribe? Copenhagen 6 15.00% Many-Worlds, a.k.a. Many-Histories, a.k.a. Relative State 6 15.00% Ensemble 4 10.00% de Broglie/Bohm 7 17.50% von Neumann 0 0% Quantum Logic 0 0% Time-symmetric theories 1 2.50% Stochastic 0 0% Many-Minds 0 0% Consistent histories 0 0% Objective Collapse 0 0% Transactional 0 0% Relational 0 0% Other (do post which one!) 4 10.00% Don't know / Agnostic / "Shut up and calculate" 12 30.00% Voters: 40. You may not vote on this poll

## Interpretation of Q.M. (with more options!)

I think Quantum Field Theory from the view of mathematical Physics gives a lot more answers than Quantum Mechanics. With that anything in space behaves according to fundamental symmetries and particles(as you measure them) and their properties are a consequence of those symmetries. The existance of only two types of statistics(Fermi-Dirac and Bose-Einstein) for particles in 4-space as an example can also be seen as direct consequence of that particles that are seperated in a spacelike manner cannot influence eachother's measurement results. In this way i find entanglement not to be too surprising. Maybe a too simplified analogy would be that if one were to throw a snowball of 1kg against a knife nobody would be surprised to find that if one half was 600g that the other is 400g. To be more general entangled particles were in contact once so why is it surprising that from the measurement of one of them one is able to predict the measurement values at the other one? Separated spacelike means they could not have been in contact with eachother (and yes the property that particles such as this could never have been in contact with eachother is used in axiomatic qft to derive what i said about statistics).
 I wouldn't place at the same level the "Don't know / Agnostic /" option with the "Shut up and calculate". These are very different categories. Anyhow, my option is any theory that abolishes completely the notion of particles, waves, even no strings or branes which I perceive as 'objects' which completely are at odds with QM, and where time and space are emergent properties.

Recognitions:
 Quote by aaa2 [...]One gets even better equations when trying to look for representations of the Poincare-group. Those representations have to be either unitary or anti-unitary so that when doing a transformation from one system of reference to another one gets the same probabilities for a measurement. If A is a representation of the Poincare group on a hilbert space and |ψ> and |ψ'> are vectors on that hilbert space then <ψ|ψ'>==:<∏|∏'> has to be true(∏ and ∏' are the vectors ψ in a transformed frame of reference). So for this to be true only unitary representations of the Poincare-group are interesting.
If you demand invariance of probabilities, i.e.,
$$\def\<{\langle} \def\>{\rangle} \frac{|\<ψ|ψ'\>|^2}{\<ψ|ψ\> \<ψ'|ψ'\>}$$
then both unitary and antiunitary transformations are possible. But the antiunitaries usually only involve time reversal.

 With these ideas you can pretty easily kill major parts of quantum field theory.
Huh?? Weinberg (and others) develop modern QFT precisely by constructing causal field representations of the Poincare group.

 The existance of only two types of statistics(Fermi-Dirac and Bose-Einstein) for particles in 4-space as an example can also be seen as direct consequence of that particles that are seperated in a spacelike manner cannot influence each other's measurement results.
Actually, one only needs little more than the theory of good ol' unitary irreps of SO(3) to get that result.

Recognitions:
 Quote by Aidyan I wouldn't place at the same level the "Don't know / Agnostic /" option with the "Shut up and calculate". These are very different categories.
Yep.

(I prefer to call the latter "Stop fantasizing & calculate".)
 @strangerep Yes i know an operator is interpreted as projector A=|ψ'><ψ'| and thus one gets <ψ|A|ψ>=|<ψ|ψ'>|^2 (if one uses wavefunctions of unit size). Yes i know that i made the error twice even and i am very surprised you are the first to realize. Also i am pretty new to quantum field theory(only had my first lesson on it(1 semester on it)) so please cut me some slack.(i did not learn anything on the standard model yet this will be in my next lessons i suppose. Essentially so far i heard a lot about representation theory.

Recognitions:
 Quote by aaa2 [...] i am pretty new to quantum field theory(only had my first lesson on it(1 semester on it)) so please cut me some slack.
OK, but in view of this, perhaps statements as strong as your previous:
 "With these ideas you can pretty easily kill major parts of quantum field theory."
should be toned down, or rephrased, when in a public forum.
 Ok i will do that i am sorry!
 This is a novel natural interpretation of QM that could be named 'intrinsic periodicity'. The idea, proposed by Dolce, is a 'conceptual' relativistic reconsideration of the 'de Broglie periodic phenomenon' at the base of the wave-particle duality: "Similarly to a "particle in a box" or to a "vibrating string", the constraint of intrinsic periodicity can be used as semi-classical quantization condition, with remarkable matching to ordinary relativistic quantum mechanics." ... without introducing any hidden variable. Title: Compact Time and Determinism for Bosons: foundations (Foundations of physics, 2011) Author: Donatello Dolce Abstract: Free bosonic fields are investigated at a classical level by imposing their characteristic de Broglie periodicities as constraints. In analogy with finite temperature field theory and with extra-dimensional field theories, this compactification naturally leads to a quantized energy spectrum. As a consequence of the relation between periodicity and energy arising from the de Broglie relation, the compactification must be regarded as dynamical and local. The theory, whose fundamental set-up is presented in this paper, turns out to be consistent with special relativity and in particular respects causality. The non trivial classical dynamics of these periodic fields show remarkable overlaps with ordinary quantum field theory. This can be interpreted as a generalization of the AdS/CFT correspondence. http://arxiv.org/abs/0903.3680 http://www.springerlink.com/content/g324131430841515/ Title: Gauge interaction as periodicity modulation (Annals of Physics, 2012) Abstract: The paper is devoted to a geometrical interpretation of gauge invariance in terms of the formalism of field theory in compact space–time dimensions (Dolce, 2011) [8]. In this formalism, the kinematic information of an interacting elementary particle is encoded on the relativistic geometrodynamics of the boundary of the theory through local transformations of the underlying space–time coordinates. Therefore gauge interactions are described as invariance of the theory under local deformations of the boundary. The resulting local variations of the field solution are interpreted as internal transformations. The internal symmetries of the gauge theory turn out to be related to corresponding space–time local symmetries. In the approximation of local infinitesimal isometric transformations, Maxwell’s kinematics and gauge invariance are inferred directly from the variational principle. Furthermore we explicitly impose periodic conditions at the boundary of the theory as semi-classical quantization condition in order to investigate the quantum behavior of gauge interaction. In the abelian case the result is a remarkable formal correspondence with scalar QED. http://www.sciencedirect.com/science...03491612000255 http://arxiv.org/abs/1110.0315 Title: On the intrinsically cyclic nature of space-time in elementary particles (Journal of Physics: Conference Series, 2012) Abstract: We interpret the relativistic and quantum behavior of elementary particles in terms of elementary cycles. This represents a generalization of de Broglie hypothesis of intrinsically "periodic phenomenon". Similarly to a "particle in a box" or to a "vibrating string", the constraint of intrinsic periodicity can be used as semi-classical quantization condition, with remarkable matching to ordinary relativistic quantum mechanics. In this formalism the retarded and local variations of four-momentum characterizing relativistic interactions can be equivalently expressed in terms of retarded and local variations of "de Broglie internal clock" space-time periodicity. http://iopscience.iop.org/1742-6596/343/1/012031 Title: de Broglie Deterministic Dice and emerging Relativistic Quantum Mechanics (Journal of Physics: Conference Series, 2011) Abstract: Generalizing the de Broglie hypothesis of intrinsically periodic matter fields, it is shown that the basic quantum behavior of ordinary field theory can be retrieved in a semi-classical and geometrical way from the assumption of intrinsic periodicity of elementary systems. The geometrodynamical description of interactions that arises in this theory provides an intuitive interpretation of Maldacena's conjecture and it turns out to be of the same type of the one prescribed by general relativity. http://iopscience.iop.org/1742-6596/306/1/012049/ http://arxiv.org/abs/1111.3319 Title: Clockwork quantum universe (IV prize, FQXi, 2011) Abstract: Besides the purely digital or analog interpretations of reality there is a third possible description which incorporates important aspects of both. This is the cyclic interpretation of reality. In this scenario every elementary system is described by classical fields embedded in cyclic space-time dimensions. We will address these cyclic fields as "de Broglie internal clocks". They constitute the deterministic gears of a consistent deterministic description of quantum relativistic physics, providing in addiction an appealing formulation of the notion of time. http://www.fqxi.org/community/essay/...s/2011.1#dolce Title: Quantum Mechanics from Periodic Dynamics: the bosonic case ( AIP Conf. Proc.) Abstract: Enforcing the periodicity hypothesis of the "old" formulation of Quantum Mechanics we show the possibility for a new scenario where Special Relativity and Quantum Mechanics are unified in a Deterministic Field Theory [arXiv:0903.3680]. A novel interpretation of the AdS/CFT conjecture is discussed. http://arxiv.org/abs/1001.2718 http://proceedings.aip.org/resource/...sAuthorized=no Title: Deterministic Quantization by Dynamical Boundary Conditions ( AIP Conf. Proc.) Abstract: We propose an unexplored quantization method. It is based on the assumption of dynamical space-time intrinsic periodicities for relativistic fields, which in turn can be regarded as dual to extra-dimensional fields. As a consequence we obtain a unified and consistent interpretation of Special Relativity and Quantum Mechanics in terms of Deterministic Geometrodynamics. http://arxiv.org/abs/1006.5648 http://proceedings.aip.org/resource/...sAuthorized=no
 Zeilinger's interpretation from his 1999 paper(A foundational principle for quantum mechanics) is my vote. I don't know if it is the same as "quantum logic".
 Zeilinger's information interpretation from his paper in 1999 (a foundational principle for QM) I don't know if this is the same as quantum logic.

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 Quote by Aidyan I wouldn't place at the same level the "Don't know / Agnostic /" option with the "Shut up and calculate". These are very different categories.
While nice in theory, "shut up and calculate" has two very serious problems:
• The premise that what you calculate has anything to do with real world (observations, experimental measurements, etc) is by definition an interpretation.
• By refusing to actively conceptualize what you're doing, you're stuck with whatever crazy thing your subconscious decides to come up with in the learning process.

I'm sure some people can overcome these obstacles when they need to do so -- but I suspect that most people just wind up thoroughly locking themselves into an interpretation without knowing what it is or that they have even done so.

 Quote by Hurkyl While nice in theory, "shut up and calculate" has two very serious problems: The premise that what you calculate has anything to do with real world (observations, experimental measurements, etc) is by definition an interpretation. By refusing to actively conceptualize what you're doing, you're stuck with whatever crazy thing your subconscious decides to come up with in the learning process. I'm sure some people can overcome these obstacles when they need to do so -- but I suspect that most people just wind up thoroughly locking themselves into an interpretation without knowing what it is or that they have even done so.
Well put.
Most people that think they follow the "shut up and calculate" way (not only in QM, but in physics in general) are just not being honest with themselves and as you say either don't realize that to connect calculations to observations there is always some degree of interpretation and conceptualization, or are holding on to a certain interpretation (conscioussly or not) and refuse to admit it for whatever the reasons.

 Quote by Hurkyl While nice in theory, "shut up and calculate" has two very serious problems: The premise that what you calculate has anything to do with real world (observations, experimental measurements, etc) is by definition an interpretation. By refusing to actively conceptualize what you're doing, you're stuck with whatever crazy thing your subconscious decides to come up with in the learning process. I'm sure some people can overcome these obstacles when they need to do so -- but I suspect that most people just wind up thoroughly locking themselves into an interpretation without knowing what it is or that they have even done so.
When I put the three options together, I really just imagined the "Shut up and calculate" interpretation to be pretty much equivalent to a position that you simply do not care what's actually going on as long as the calculations represent stuff that's actually going on in the end, no matter how they got there. But maybe it's right that they should've been separate options.

But well, since this is already the second one, I'm not about to do another poll!

 Quote by TrickyDicky Well put. Most people that think they follow the "shut up and calculate" way (not only in QM, but in physics in general) are just not being honest with themselves and as you say either don't realize that to connect calculations to observations there is always some degree of interpretation and conceptualization, or are holding on to a certain interpretation (conscioussly or not) and refuse to admit it for whatever the reasons.
Indeed. I think that's a basic error in science, because it's my personal belief that one should always try to match his map with the territory as accurately as possible, and always search for the Truth, but that's my opinion :P

 Tags copenhagen, ensemble, interpretation, many worlds, wavefunction