On Friday, November 1, 2019 at 3:57:39 AM UTC-6, Bruno Marchal wrote: > > > On 31 Oct 2019, at 23:49, Alan Grayson <[email protected] <javascript:>> > wrote: > > > > On Thursday, October 31, 2019 at 6:04:58 AM UTC-6, Bruno Marchal wrote: >> >> >> On 30 Oct 2019, at 21:50, Alan Grayson <[email protected]> wrote: >> >> >> >> On Tuesday, October 29, 2019 at 5:53:10 PM UTC-6, Alan Grayson wrote: >>> >>> >>> On Tuesday, October 29, 2019 at 5:18:45 PM UTC-6, Brent wrote: >>>> >>>> >>>> On 10/29/2019 3:48 PM, Alan Grayson wrote: >>>> >>>> >>>> On Tuesday, October 29, 2019 at 1:55:17 PM UTC-6, Brent wrote: >>>>> >>>>> >>>>> >>>>> On 10/29/2019 12:46 PM, Alan Grayson wrote: >>>>> >>>>> >>>>> >>>>> On Tuesday, October 29, 2019 at 1:25:43 PM UTC-6, Brent wrote: >>>>>> >>>>>> >>>>>> >>>>>> On 10/29/2019 11:43 AM, Alan Grayson wrote: >>>>>> >>>>>> What does that mean? No one even detects them. They need not even >>>>>>> be absorbed, but could simply fly off to infinity. >>>>>>> >>>>>>> Brent >>>>>>> >>>>>> >>>>>> What exactly is the situation? Interference is destroyed, more and >>>>>> more, as they get hotter, but without any observations? AG >>>>>> >>>>>> >>>>>> Right. >>>>>> >>>>>> Brent >>>>>> >>>>> >>>>> It sounds like some sort of hidden variable (don't take this too >>>>> literally), where the particles send out information of whether >>>>> interference will occur or not, and it doesn't matter if it's observed. >>>>> This could fit into my model of superposition with some modification; >>>>> namely, it you do a which-way experiment, OR if information about >>>>> which-way >>>>> is available, interference is destroyed. And what goes through the slits >>>>> in >>>>> the absence of these conditions is a wave going through both slits. AG >>>>> >>>>> >>>>> OK. Except "send out" doesn't make sense. It implies signaling, >>>>> which would be at less than light speed (c.f. delay choice quantum eraser >>>>> experiment). >>>>> >>>>> Brent >>>>> >>>> >>>> What descriptive term do you prefer? Those IR photons travel at the >>>> SoL. The point is that if there's information available for which-way, >>>> even >>>> if not observed, the interference is destroyed. AG >>>> >>>> >>>> What does "available" mean? The information that left at the speed of >>>> light is not "available" in any conventional sense at the screen or >>>> detector in the experiment. >>>> >>>> Brent >>>> >>> >>> That's the mystery we have to figure out. What we know, is that the >>> particles release IR photons which could be observed, and when that >>> emission occurs, interference disappears. It doesn't even depend on any >>> observations being made. AG >>> >> >> I would revise my interpretation this way; the electron, or whatever, >> behaves as a wave when no information exists to distinguish which-way, and >> that wave goes through both slits producing interference. When such >> information exists, even if it isn't used or measured, the interference >> ceases to exist. Obviously, there's a huge mystery how the existence of >> such information is sufficient to destroy interference, but that's what the >> experimental results demonstrate. AG >> >> >> That huge mystery disappears when you apply QM to the particles *and* to >> the observers and all things they interact with. The interferences are >> never destroyed, >> > > > I don't see how this simplifies anything. Sometimes the local observer > sees interference; sometimes not depending on whether which-way information > exists. How does your model explain this? AG > > > Take the cat C, assuming it well isolated in its box. The cat is in the > state 1/sqrt(2) (a + d). Now imagine that the box was not so well isolated, > and some particle P interact with it. Let us describe the state of the > particle, in case the cat would ba alive by P_a, and P_d if the cat was > dead. As the cat is in the state a + d, the new state is: > 1/sqrt(2) (P_a a + P_d d). OK? > > If I was ware of that particles, I could in principle obtain interference > pattern from that (pure) superposition. In particular, I could erase the > “memory” of the interaction of the particle, so that I can factor again P > from the state above, and get back the interference available from a + d. > > But if I cannot track that particle, I am unable to do that, and the > interaction with the particle has destroyed my mean to get back to the a + > d state, and I am confronted with what I will take as a mixed state. It > looks like a collapse, but it is only because the superposition of the cat > has leaked to the environment in a way making impossible for me to get back > to the a + d state. > > So, there is no collapse, but the fact that the superposition has leaked > in the environment, without me knowing any details on this, makes the state > of the cat equivalent to a mixture of a and d state. FAPP, the cat is > either dead or alive after that unknown and untrackable information. > > We see that a measurement is only an entanglement, and we don’t need a > collapse postulate to explain why even an “unknown measurement made by some > cosmic particle” prevents me to keep the superposition of the cat available > to me. > > Bruno >
Forget about collapse or no collapse; forget about cats. The fact is that with electrons or whatever, sometimes we see interference patterns, and sometime not. In the latter case it occurs when which-way information exists, and it doesn't matter if we use or observe that data by instruments or by human observers. I don't see how your previous message remotely offers an explanation. AG > > > > > > but assuming that the observers are machines and that they obey to QM > explains entirely why they feel like memorising that the interference have > disappeared, and why they are locally right about this. > > Either the observer obeys QM, and inherits the superposition of what they > are observing through measurement/entanglement, or QM is false for the > observer, and we have to wait for some theory of what is an observer, > together with some criteria for when and where we can use QM. > > Bruno > > > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/9d13eee6-5f1c-4a0d-a51a-4a8a6474ff0e%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/9d13eee6-5f1c-4a0d-a51a-4a8a6474ff0e%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/9facd6dd-7ab5-483a-84c9-83f58b9c7c92%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/9facd6dd-7ab5-483a-84c9-83f58b9c7c92%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/04322a49-feef-4f0c-97ce-e5ae51c9e5ef%40googlegroups.com.
