# Tag Info

1

There is absolutely no "freedom for interpretations" here. Both books should – and all other books that are not completely wrong do – agree with these formulae and agree that $a_n$ never indicates an eigenvalue. In both books and all of science, $a_n$ is the complex probability amplitude such that $|a_n|^2$ represents the probability that the system has ...

0

It's spin-orbit coupling in QCD--ala hyperfine splitting; however, in QCD it's not so fine.

0

Take for example the double-slit experiment interpreted in the Copenhagen sense. The particle leaves as an object with mass, yet passes through the slits as a massless wave, only to collapse again as a particle. We can consider this example as a generalisation of the principle of anti-realism posited by Bohr. Where does the energy "go" when the ...

2

Short answer: no. I'll give some context with the details of the simplest examples. In the context of conservation laws, "energy" refers to the Hamiltonian. In classical mechanics, a quantity without explicit time dependence is conserved iff its Poisson bracket with the Hamiltonian is 0. In quantum mechanics, quantities are promoted to operators on a ...

0

Everything is fundamentally deterministic. However, randomly complex and unknown factors make certain phenomena appear probabilistic. For example tossing a coin has 50/50 probability. But we know that complex/unknowable factors and their random nature make the toss a probabilistic phenomenon. The factors are so random at an immeasurable level that the ...

0

For some counterarguments against Lubos Motl's argumentation against de Broglie-Bohm theory see http://ilja-schmelzer.de/forum/forumdisplay.php?fid=6 and http://ilja-schmelzer.de/realism/Motl.php The first proposal for a Bohmian variant of a relativistic quantum field theory has been made in Bohm's original 1952 paper, for the EM field. For a possibility ...

-1

One should distinguish here de Broglie-Bohm theory for the general situation outside the equilibrium, and that for quantum equilibrium. Entropy is defined as usual by $H=-\int \rho \ln \rho dq$. Outside the quantum equilibrium it is useful to split it into the entropy relative to the quantum equilibrium $H=-\int \rho \ln (\rho/|\psi|^2) dq$. This relative ...

7

Dirac does not intend classical to mean non-quantum mechanics; he intends classical to mean pre-quantum mechanics1. So no, this says nothing about de Broglie–Bohm theory. Dirac opens his paragraph with The necessity for a departure from classical mechanics is clearly shown by experimental results. Dirac is not talking about any theory that one ...

4

Yes, absolutely, Dirac's argument shows that one could never construct a complete theory – which specifies the rules for evolution as well as predictions for the measurement and what happens after the measurement – that would be compatible with the basic facts about the atoms. This no-go theorem applies to Bohmian mechanics because it is just another ...

0

In the many world interpretation of quantum mechanics, there is only a split into different branches when decoherence takes place. So there would be no split in the two slit experiment until the photon hits the photographic plate. At that stage decoherence takes place and there would be a split into a separate Universe (branch) each of which has the photon ...

3

Firstly, I find the hostility against many worlds interpretation inadequate. As far as understanding quantum mechanics goes, the case is far from closed. I believe that it is unlikely, that this question will be answered near future (and it is plausible that it will be never resolved). Nevertheless, something being inherently hard should not suppress our ...

3

As stated by Luboš Motl in another answer, there is no consensus between Everett's interpretation contenders about what it means exactly. The common idea is that no state evolution other than unitary as per Schrödinger should be accepted (no collapse) but that's about it. Indeed it is not clear at all what is supposed to be splitting or branching, and when. ...

3

For the specific case of a fixed number of interacting spinless point particles, there is a Bohmian recipe that works fine: you start with solutions to the Schrodinger equation, construct trajectories from the gradient of the probability current, and assign a probability measure to those trajectories according to the Born rule. That gives you a "classical" ...

-4

deBroglie developed double solution theory, which is the most relevant description of photon and the Bohm / orthodox quantum mechanics are just high/low energy limits of that model. It should be pointed out that de Broglie disagreed with Bohmian mechanics.

2

The assumption of "freedom" in the Bell inequality derivation is a somewhat misleading statement. It is not an assumption of freedom in the philosophic sense. Rather, it is the statement that the experimenter's choice of measurement basis should not be correlated with the quantum state they are measuring. For example, one could set the measurement apparatus ...

0

The Many Worlds Interpretation is a theory of non relativistic quantum mechanics where there is a wavefunction from the configuration space of the entire system (and this is utterly essential) into the joint spin state of the entire system and it evolves according to the Schrödinger equation, and nothing else. No one claims (or has ever claimed) that in one ...

10

There doesn't exist any "totally well-defined" realization of MWI but its champions want to agree with the basic experimental facts so they would almost certainly say that there is no splitting of the worlds when a particle goes through two slits. Instead, if there's any splitting of the worlds at all, and different MWI advocates have different opinions ...

2

The inflationary theory you mention is probably eternal inflation. In this theory there is just one universe but different parts of it are causally disconnected i.e. the different parts cannot affect each other in any way. Whether these constitute a multiverse comes down to terminology. In principle there is a continuous spacelike straight line that links ...

1

This is a profound question at the heart of science. Indeed no little effort has been devoted to trying to understand whether the mathematics of quantum mechanics are simply a contrivance or reflect reality. Surprisingly, Bell discovered an experimental method to answer the question and the result is that quantum weirdness is an intrinsic aspect of nature. ...

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