On 10/11/2019 6:25 PM, Alan Grayson wrote:
On Friday, October 11, 2019 at 7:20:43 PM UTC-6, Alan Grayson wrote: On Friday, October 11, 2019 at 6:05:23 PM UTC-6, Brent wrote: On 10/11/2019 2:13 PM, Alan Grayson wrote:On Friday, October 11, 2019 at 1:50:34 PM UTC-6, Brent wrote: On 10/11/2019 11:35 AM, Alan Grayson wrote:On Friday, October 11, 2019 at 12:27:19 PM UTC-6, Alan Grayson wrote: On Friday, October 11, 2019 at 12:10:27 PM UTC-6, Brent wrote: On 10/11/2019 12:18 AM, Alan Grayson wrote: > I am saying that SINCE there is no unique representation, it's a > fallacy to take, say one representation, and assert that the > components in one representation, simultaneously represent the wf. But that's an invalid inference. If there is no unique representation, then there is more than one representation. Some of those consist of a linear composition of components. You seem to infer that because there is no unique representation then representations in terms of components is wrong...but those two things are not only consistent, they are logically equivalent; each one implies the other. Brent No; on the contrary, I think all the representations are valid. What's invalid is singling out one representation and asserting the system is simultaneously in ALL the components of THAT representation. AG I wasn't clear in one or more of my previous comments, but the latter is what I meant. All representations are valid; basic linear algebra. But to ascribe ontological status to one particular set of components, when in general there exists an uncountable set, is a fallacy. I thought I illustrated that point with S's cat. AGContrast the SG experiments with silver atoms. In that case the different bases are equally real, but an atom can be in definite spin state, say UP, which is a superposition of LEFT and RIGHT. This can be confirmed by measuring in the LEFT/RIGHT basis. So did the LEFT/RIGHT components exist when the atom was in the UP state? That sounds like a metaphysical or semantic question about the meaning of "being in" a state. But Schroedinger's cat is different because it is impossible to measure in the |LIVE>+|DEAD> and |LIVE>-|DEAD> basis. That was Schroedinger's point that this superposition is absurd. But why is it absurd? The best answer seems to be Zurek's einselection, meaning it's/not/ because there's an uncountable set of bases in the LIVE/DEAD hyperplane, but because only |LIVE> and |DEAD> are stable states against environmental interaction. Brent There may be some exceptions for my claim. I need to study the silver atom case and get back to you. But in the case of S's cat, I think the problem is with the alleged quantum states of |Live> and |Dead>. What is the operator that has those states as eigenstates? If it can't be specified, maybe the construct makes no sense. AGWell none, or at least none that anyone could possibly implement as a Hermitean projection operator of some instrument. Schrodinger just chose ALIVE/DEAD to emphasize how absurd it was to attribute superpositions to macroscopic objects. But he didn't know /why/ it was absurd. He could have stuck to just the radioactive atom decaying or the geiger counter tube detecting it, but that wouldn't have been obviously absurd. Brent I agree with that! If it shows that superpositions cannot be attributed to macroscopic objects, then perhaps the idea that everything is quantum is precarious, if not false. And if he didn't need a cat, just a radioactive source, what would the consequences have been? AGMaybe Schroedinger wanted to show that superposition was inherently absurd, when interpreted as a radioactive source being decayed and undecayed simultaneously -- which is what I have been claiming on other grounds. AG
But that's not absurd, because it is possible to have a radioactive atom that is isolated from all environment and other degrees of freedom and so it might exist in a superposition. This is how quantum computers gain power compared to classical computers. Qubits exist in superpositions. But it's hard to keep them cold enough and isolated enough for long enough to computer something.
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