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Feb
27
comment What are the 't Hooft papers about classical models underlying QM?
Our theory is now that physicists describing the real world have no way of knowing whether they are describing an ontological event, or just any other solution of their equations (except when it's about cats, where we think we DO know!). The simple reason for this is that Schroedinger's equation is linear. We keep that property throughout. But now I add something new: a true, ontological state should, some way or other, evolve to become again a true, ontological state. That's just a constraint on the set of Schroedinger's equations that we impose. What's wrong with that? Nothing of course,
Feb
27
comment What are the 't Hooft papers about classical models underlying QM?
There's this little point that @Motl failed to grasp about these models: It's the "ontological, true" events described here that are such that any superposition of such events is NOT an ontological event. That's just like cats: the dead cat is ontological, the live one is, but any superposition of the two isn't, or at least, that's the case in our models. Now the superposition of the two cats DOES obey Schroedinger's equation. What I have done is take all "ontological" states of a system and look at the equations they obey. Now superpositions of ontological states also obey the equations.
Dec
27
awarded  Good Answer
Nov
8
comment Will Determinism be ever possible?
sigoldberg1 and Seamus's remarks about Laplace apply if the world is described by real numbers. The problem with real numbers is that they each require infinite sets of digits. If you can't control the millionth digit you will have indeterminism. This problem would not arise if we would have theories based only on integers, or even better, bounded integers.
Nov
7
comment Will Determinism be ever possible?
Indeed, I should have stated more clearly that I mean local reality, and that this should be interpreted in a completely classical sense. But, as you say, this "reality" is not about particles with position, momentum, etc. My minority view is that there is a loophole in the arguments usually employed against local reality.
Nov
4
awarded  Citizen Patrol
Nov
4
answered Will Determinism be ever possible?
Nov
1
comment Is flying really easier on smaller scales?
Apologies to AlanSE, my comments and questions were to be directed to @miceterminator.
Nov
1
revised Is flying really easier on smaller scales?
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Oct
30
comment Is flying really easier on smaller scales?
But this is what I read on my screen, signed by your name. If you didn't mean $\sqrt{\text{diameter}}$, then what are you trying to say?
Oct
28
comment Is flying really easier on smaller scales?
@AlanSE Please explain why you write $\sqrt{\text{diameter}}$ where I would have expected $\text{diameter}^2$, assuming that strength of muscle tissue is more or less size independent. Of course, the energy produced by a muscle scales with its volume, times frequency.
Oct
28
revised Is flying really easier on smaller scales?
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Oct
27
answered Is flying really easier on smaller scales?
Sep
15
revised Why do people categorically dismiss some simple quantum models?
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Sep
12
comment Why do people categorically dismiss some simple quantum models?
In principle, yes, one should be able to construct a Bohmian field theory, but I think it would be inelegant. To my taste, Bohmian mechanics adds far too many "unobservable observables" in the form of pilot waves. This would be awful for field theories, where the pilot wave would be a field functional, or a function of infinitely many particle positions.
Sep
7
comment Why do people categorically dismiss some simple quantum models?
Think of qft as a large set of quantum harmonic oscillators, each oscillating at isolated points in space. Then assume that each oscillator shows interactions only with its direct neighbors. In qft, these are quantum interactions. To most theorists, this looks sufficiently local, no spooky signals.
Sep
7
comment Why do people categorically dismiss some simple quantum models?
@user7348: No, quantum field theory as it stands has causality built in; for that, it is sufficient to demand that all commutators vanish outside the light cone. This guarantees that no signal ever will go faster than light. So qft obeys relativity and has ordinary qm particles in its non-relativistic limit. Everything is fine, no problem with relativity, until you try to understand what the ontology is. You have to remember that spacelike correlations are fine if you can explain them in terms of intial states in the past.
Sep
6
comment Why do people categorically dismiss some simple quantum models?
If you repeat an experiment, or do it many times, you therefore can't modify one observable without affecting an other one, somewhere, somehow. It is difficult to understand how this happens, you have to remember that the vacuum surrounding us is a very complicated entangled state. All this is the real reason why Bell may be violated in the CA. So I ignore Bell, and in that case qm (rather: qft) is local.
Sep
6
comment Why do people categorically dismiss some simple quantum models?
@ user7348: I do not accept Bell's theorem that easily. It is difficult to see exactly what happens, but it is crucial that all CA observables at all times commute. After my unitary mapping, therefore, only observables that are orthogonal to each other are uniquely defined in terms of CA variables. Now, since the mapping is complicated, these observables are different every time you do an experiment. Therefore we can have counterfactual observables that do not commute.
Sep
6
comment Why do people categorically dismiss some simple quantum models?
@ drake: I don't know what theories you talk about. In my theory, obtained from a local mapping from a local CA, the only non-locality is over a small number of lattice sites. Further away, all commutators outside the light cone do vanish.