tag:blogger.com,1999:blog-22973357.post8721587634297364067..comments2020-07-05T15:55:09.557-04:00Comments on Sabine Hossenfelder: Backreaction: What is the quantum measurement problem?Sabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger236125tag:blogger.com,1999:blog-22973357.post-22790328597131581262019-11-27T09:07:44.379-05:002019-11-27T09:07:44.379-05:00A lot of what you say reminds me of David Bohm, hi...A lot of what you say reminds me of David Bohm, his implicate order. It seems that even in a classical framework, if we look at any arbitrary part of the universe, the rest of the universe seems implicit. For that matter, we perform experiments and they are nothing if not local events, even if we are looking through a telescope, observing, the observations are all local events. And we derive someRick Lubbockhttps://www.blogger.com/profile/01070357751075383393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-52254424698626798262019-11-27T07:08:16.693-05:002019-11-27T07:08:16.693-05:00He also claims to have now written the definitive ...He also claims to have now written the definitive work on the interpretation. Contact him to find where you can get a copy. I like Dr Neumeier - he has corrected a number of misconception I had, but ultimately I find his views over complicated. Still - this is science - who know he may be right.Bill Hobbahttps://www.blogger.com/profile/16338177722812452753noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-82033575256132222732019-11-27T07:01:47.975-05:002019-11-27T07:01:47.975-05:00I have thought about the measurement problem for I...I have thought about the measurement problem for I do not know how long. The conclusion I have reached is its like throwing a dice - how does a one in 6 probability become a 1 once it is thrown. The measurement problem seems exactly the same - except for the dice we know exactly how it becomes a one - in QM we do not not know the mechanism or even if there one. I do not see why that lack ofBill Hobbahttps://www.blogger.com/profile/16338177722812452753noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-77264921958515519952019-11-05T04:41:06.970-05:002019-11-05T04:41:06.970-05:00The thermal interpretation was defined in Section ...The thermal interpretation was defined in Section 2.5 of Part II of my series of preprints; see http://www.mat.univie.ac.at/~neum/physfaq/therm/thermalMain.html . The definite presentation of the thermal interpretation is in Section 9.2 of my recent book Coherent Quantum Physics: A Reinterpretation of the Tradition, de Gruyter, Berlin 2019. https://www.degruyter.com/view/product/537801Arnold Neumaierhttps://www.blogger.com/profile/14996780183059531293noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-4361884538521238422019-11-04T01:25:30.109-05:002019-11-04T01:25:30.109-05:00There is no such thing as superposition. It is bas...There is no such thing as superposition. It is based on an oxymoronic concept that you call the uncertainty principle. But restate it properly, "you can't know the state of rest, position, or the state of unrest, momentum. of ant particle with an accuracy greater that than h/2pi. Well duh, if you are seeking its state of rest you will find a particle and if you are seeking its state of Lumina Celeritas aka Frank Williamshttps://www.blogger.com/profile/16519249596090186765noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-90398536864167349652019-11-03T14:38:09.704-05:002019-11-03T14:38:09.704-05:00One dubious assumption in the MWI case is that the...One dubious assumption in the MWI case is that the alternative 'single world' versions of QM necessarily involve some form of 'collapse'. However, underneath the apparent stark differences we find that both the MWI and Collapse interpretations are actually attempts to prop-up the same idea, the idea that the sets of equations that satisfy the Schrödinger equation correspond to JKNMhttps://www.blogger.com/profile/11779607271869750628noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-83046008350883868522019-11-03T04:54:10.973-05:002019-11-03T04:54:10.973-05:00Thomas Payne: Note that the Schrodinger equation i...Thomas Payne: Note that the Schrodinger equation is not what describes the evolution of a system. The Schrodinger equation is in effect a condition that takes all possible equations of motion and produces a set of wave-functions that describe what we term 'states'. These sets of 'wave functions' are not required to be linear, it just so happens that when we use linear equations weJKNMhttps://www.blogger.com/profile/11779607271869750628noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-34635516535477586072019-11-01T08:36:59.797-04:002019-11-01T08:36:59.797-04:00Nature is local and quantum mechanical.
Since the...Nature is local and quantum mechanical.<br /><br />Since the 20's physicists know that the phase space of classical mechanics does not applies to molecules, electrons, photons, etc ... because of the non-commutativity of observables.<br />The probabilistic description developed by Bohr, Born, Heisenberg and others is the right one. There is no way to restore classical mechanics and "isometrichttps://www.blogger.com/profile/13630274939107848604noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-4740204365157775222019-11-01T02:57:07.322-04:002019-11-01T02:57:07.322-04:00Udi,
"Usually, the term “non-linear” refers ...Udi,<br /><br /><i>"Usually, the term “non-linear” refers to a process that is obviously non-linear.</i><br /><br />I have no idea what you mean. A process is either linear or not. The meaurement process is not linear, as you can easily check for yourself. This cannot possibly be so hard to understand.<br /><br /><i>"It is an important distinction. If you say that a system is non-linearSabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-74462929407578082102019-10-31T22:45:59.311-04:002019-10-31T22:45:59.311-04:00Sabine wrote:
“State 1 goes to detector eigenstat...Sabine wrote:<br /><br />“State 1 goes to detector eigenstate 1. State 2 goes to detector eigenstate 2. State 1 + State 2 will not go to detector eigenstate 1 + detector eigenstate 2. This means it is not a linear process by definition.”<br /><br />The way you put it, the most obvious way to describe it linearly is the MWI way, where State 1 + State 2 does indeed go to detector eigenstate 1 + Udi Fuchshttps://www.blogger.com/profile/02529460830838964526noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-48184136053341294832019-10-31T02:08:36.153-04:002019-10-31T02:08:36.153-04:00Udi,
"You on the other hand, claim that meas...Udi,<br /><br /><i>"You on the other hand, claim that measurement is non-linear, but you offer no proof for your claim."</i><br /><br />The measurement is non-linear. What do you want me to even prove. I said this in my video and I have said this N>3 times in this comment thread. State 1 goes to detector eigenstate 1. State 2 goes to detector eigenstate 2. State 1 + State 2 will not Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-72499538724962107682019-10-30T21:37:10.921-04:002019-10-30T21:37:10.921-04:00Sabine wrote:
“Well, maybe I am being to polite. ...Sabine wrote:<br /><br />“Well, maybe I am being to polite. The example you named above has two operaters each of which will project one particular state into an eigenstate. What you need is an evolution law that brings *any* initial state (of any system) into a detector eigenstate. Your model is wrong. Have I expressed this clearly enough now?”<br /><br />Don’t worry about being polite with me, Udi Fuchshttps://www.blogger.com/profile/02529460830838964526noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-22915938193179914542019-10-30T17:35:35.761-04:002019-10-30T17:35:35.761-04:00"How can an observer, described solely as an ..."How can an observer, described solely as an uncollapsed superposition of eigenstates as per the Schrödinger equation, measure a definite outcome?"<br /><br />The observer state after the measurement only describes the probabilities of all possible observations. Just like the system state before the measurement described the probabilities of all possible outcomes. The only empirical single_world_interpreterhttps://www.blogger.com/profile/02370138516934087366noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-56072348229230963592019-10-30T02:39:24.164-04:002019-10-30T02:39:24.164-04:00Lawrence Crowell10:49 AM, October 23, 2019
"...Lawrence Crowell10:49 AM, October 23, 2019<br /><br />"This is even though there are some funny things that happen related to Gödel's theorem"<br /><br />What funny things are you referring to?<br /><br />" and something really odd called the Banach-Tarski theorem."<br /><br />It's not odd. It is an abstract mathematical theorem. It would apply in physics if a Steven Evanshttps://www.blogger.com/profile/13898046706669437332noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-29745495789302060172019-10-30T01:50:57.928-04:002019-10-30T01:50:57.928-04:00Udi,
Well, maybe I am being to polite. The exampl...Udi,<br /><br />Well, maybe I am being to polite. The example you named above has two operaters each of which will project one particular state into an eigenstate. What you need is an evolution law that brings *any* initial state (of any system) into a detector eigenstate. Your model is wrong. Have I expressed this clearly enough now?<br /><br />As to many worlds. I have told you previously that Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-27013185831068606252019-10-29T22:29:11.887-04:002019-10-29T22:29:11.887-04:00Sabine wrote:
“You said you can come up with a li...Sabine wrote:<br /><br />“You said you can come up with a linear model. I asked you to provide one. You did. I pointed out that it does not work. Instead of admitting that you were wrong you simply go back to claiming you can come up with a linear model.”<br /><br />I don’t see where you pointed out that my model does not work. The closest statement you made was: “And now please show that Udi Fuchshttps://www.blogger.com/profile/02529460830838964526noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-86811056887323967632019-10-29T17:00:52.381-04:002019-10-29T17:00:52.381-04:00Pavlos,
I like your idea of a nanodetector very m...Pavlos,<br /><br />I like your idea of a nanodetector very much! In fact, allow me to go one up on it:<br /><br />Imagine creating a detector so miniscule that it barely has enough states to go chaotic… or perhaps not even that many, just 'a lot' of states.<br /><br />If observation is nothing more than statistical irreversibility, what happens when such a nanodetector 'sees' an Terry Bollingerhttps://www.blogger.com/profile/03915136249111338024noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-40989517513530711782019-10-29T15:45:22.806-04:002019-10-29T15:45:22.806-04:00In Basic QM courses, the wave packet collapse is a...In Basic QM courses, the wave packet collapse is a separate postulate A, describing a very different process from the continuous evolution B driven by differential equations (Schrodinger equation). It is described mathematically by a projection which is fundamentally something unlocal and discontinuous. Most efforts have been toward reducing A to B, that is either showing that this kind of F henry-couannierhttps://www.blogger.com/profile/13933350696243790692noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-11080382654130100132019-10-29T10:24:36.766-04:002019-10-29T10:24:36.766-04:00single_world: How can an observer, described solel...single_world: How can an observer, described solely as an uncollapsed superposition of eigenstates as per the Schrödinger equation, measure a definite outcome? I think Sabine would hold that measurement cannot take place if both the observer and the observed are both described by the uncollapsed Schrödinger equation; you need something else, specifically a collapse postulate, which is Thomas Paynehttps://www.blogger.com/profile/10484887364914470241noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-49206125528330877102019-10-29T05:49:19.383-04:002019-10-29T05:49:19.383-04:00Nano-cat experiments have been done. I don't h...Nano-cat experiments have been done. I don't have references at the tips of my fingers, but Schrödinger cats that are nanobots have been employed to look at these issues.Lawrence Crowellhttps://www.blogger.com/profile/12090839464038445335noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-68385952904853562202019-10-29T04:43:26.547-04:002019-10-29T04:43:26.547-04:00"The P(Y=y|X=x, ψ) is the conditional probabi..."The P(Y=y|X=x, ψ) is the conditional probability computed by Bayes' rule. This is completely in line with a collapse phenomenology."<br /><br />I just told you why this is almost never the case. Whether psi -> |x> or not cannot be irrelevant to the alleged necessity of the collapse, since psi -> |x> is precisely what "collapse" means.<br /><br />What single_world_interpreterhttps://www.blogger.com/profile/02370138516934087366noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-52343982994878368272019-10-29T04:16:00.145-04:002019-10-29T04:16:00.145-04:00>Does a branch with a larger weight correspond ...>Does a branch with a larger weight correspond to more worlds than a >small weight one?<br />Andrei: I don't think so. As far as as I understand, in MWI one branch = one world.Pascalhttps://www.blogger.com/profile/14201150679841329835noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-51887584363423732582019-10-29T03:52:34.298-04:002019-10-29T03:52:34.298-04:00Many worlds, if still included in measurable conti...Many worlds, if still included in measurable continuum without wasted unrealized events of parallel worlds, can solve the measurement problem. <br /><br />That can be modelled in minimum with two antipodal causal continuums which do not interact with each other but fall fundamentally at the same rate.<br /><br />We say the position/polarization of measurer choose either continuum when measuring. Eusahttps://www.blogger.com/profile/14114706429392111062noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-11603839965675881722019-10-29T01:47:23.104-04:002019-10-29T01:47:23.104-04:00Measurement does not rule out the observer; measur...Measurement does not rule out the observer; measurement certainly involves the observer. Gokul Gopisettihttps://www.blogger.com/profile/00044660491634948291noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-62697219973336225382019-10-29T01:36:51.958-04:002019-10-29T01:36:51.958-04:00This link on the results of Heriot-watt experiment...This link on the results of Heriot-watt experiment, Edinburg, https://phys.org/news/2019-09-quantum-entitled-facts.html, test Wigner's friend paradox.<br /><br />The gist is this:<br />"Science is based on facts that are established by independent observations agreed by everyone. . . In the 1960s, the renowned scientist, Eugene Wigner, proposed an intriguing thought experiment. An Gokul Gopisettihttps://www.blogger.com/profile/00044660491634948291noreply@blogger.com