tag:blogger.com,1999:blog-22973357.post1842915188455689696..comments2020-07-12T10:17:49.861-04:00Comments on Sabine Hossenfelder: Backreaction: Book Review: “Beyond Weird” by Philip BallSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger28125tag:blogger.com,1999:blog-22973357.post-3921085508399030152019-06-26T01:03:43.339-04:002019-06-26T01:03:43.339-04:00Hi all
Thanks, Sabine, for the review of this boo...Hi all<br /><br />Thanks, Sabine, for the review of this book. I read it and it was great fun.<br /><br />One question came to my mind while reading the passages about decoherence: Could what we call „big bang“ have been not so much the „beginning of expansion from an infinite small point“ but rather the moment when decoherence of a prior existing quantum state started? The expanding universe Pascal Häußlerhttps://www.blogger.com/profile/11396713612797829828noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-81593482606786341032019-06-15T11:55:25.972-04:002019-06-15T11:55:25.972-04:00Philip Ball's book sounds very interesting, an...Philip Ball's book sounds very interesting, and I plan to purchase it. Recently I checked out The Reference Frame, and Lubos Motl has a post titled: "Bell's inequality is straightforward, the quantum world is local. I've seen this assertion on his blog on other posts that QM is local, which quite surprised me when I first encountered this position. Bell's book, and many David Schroederhttps://www.blogger.com/profile/18048116250413347228noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-77565311402365483072019-06-12T01:28:10.005-04:002019-06-12T01:28:10.005-04:00Matti,
Yes, that is the part. I think it explains...Matti,<br /><br />Yes, that is the part. I think it explains the problem very well. I doubt that if Ball's explanation doesn't work for you I can do any better. Though I may write something about the topic in future blogpost. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-9584490160286310752019-06-11T10:48:21.935-04:002019-06-11T10:48:21.935-04:00https://www.quantamagazine.org/why-the-many-worlds...https://www.quantamagazine.org/why-the-many-worlds-interpretation-of-quantum-mechanics-has-many-problems-20181018/<br /><br />Is this the part about many worlds and measurement problem? I did not see any problem. It seems like the author did not like the conclusion and therefore decided it was wrong. Maybe I missed a deep point or maybe there is an other argument in the book. Mattihttps://www.blogger.com/profile/16378902135503029904noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-74680546594704745282019-06-11T08:24:07.222-04:002019-06-11T08:24:07.222-04:00The comments here seem to me to underestimate the ...The comments here seem to me to underestimate the importance of the empirical successes of MOND. MOND's empirical successes seem to suggest that something is profoundly wrong with Newtonian-Einsteinian gravitational theory and at least one of Newtonian's 3 laws of motion — and perhaps the 1st law of thermodynamics. My guess is that the necessity of a new paradigm of the foundations of David Brownhttps://www.blogger.com/profile/10537922851243581921noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-13949536929358281372019-06-11T06:31:17.351-04:002019-06-11T06:31:17.351-04:00I don't even know how to deconstruct this.I don't even know how to deconstruct this.Philip Thrifthttps://www.blogger.com/profile/03021615111948806998noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-30734078493279632852019-06-11T01:02:45.763-04:002019-06-11T01:02:45.763-04:00Tim E,
I wrote about the relational interpretatio...Tim E,<br /><br />I wrote about the relational interpretation <a href="http://backreaction.blogspot.com/2006/05/nonlocality.html" rel="nofollow">a long time ago</a> (one of the first things I wrote on this blog). I don't know of course why it receives so little attention but I would guess it's because really it doesn't solve any problem. At least I don't see how. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-91035728912404479552019-06-10T17:42:02.985-04:002019-06-10T17:42:02.985-04:00I find it quite amusing and right to the point how...I find it quite amusing and right to the point how Claes Johnson, a Professor of Applied Mathematics, classifies QM: “Quantum Mechanics is unphysical because its interpretation is statistical which makes it non-physical, because physics is not an insurance company.”Dirk Freylinghttps://www.blogger.com/profile/15330626465475439718noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-30259689761774225542019-06-10T15:51:56.841-04:002019-06-10T15:51:56.841-04:00The description of MOND introducing new forces on ...The description of MOND introducing new forces on galactic scales isn't right: it is not about distance/scale at all. It introduces new forces at low accelerations, and can become Newtonian ("dark matterless") under the external field effect which is frequently neglected by those trying to falsify MOND. Although ideally one would really try to falsify a relativistic version: we Kirk Moodeyhttps://www.blogger.com/profile/12235699555716621615noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-18608673757823484572019-06-10T12:51:30.834-04:002019-06-10T12:51:30.834-04:00I am a big fan of this blog and Dr. Hossenfelder&#...I am a big fan of this blog and Dr. Hossenfelder's work, but I'm a first time commenter. This seems like a good time to ask a burning question I have had for many years.<br /><br />I read Beyond Weird and was waiting anxiously for a discussion of the relational interpretation of quantum mechanics (as popularized in a recent book by Carlo Rovelli), but it only got a passing mention, which Tim E.https://www.blogger.com/profile/05224465005840479323noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-90440948422835550502019-06-10T08:00:47.449-04:002019-06-10T08:00:47.449-04:00Yes, I already answered this question above. Yes, I already answered this question above. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-59021976397078437392019-06-10T07:21:01.315-04:002019-06-10T07:21:01.315-04:00Dear Sabine,
I wonder if you can clarify why you ...Dear Sabine, <br />I wonder if you can clarify why you state that "there isn’t really such a thing as the Copenhagen interpretation", but then you recognize that in this book one can learn "what the major interpretations of quantum mechanics are (Copenhagen, QBism, Many Worlds, Collapse models, Pilot Waves)", to me taking for granted that all those interpretations exists.<br /callmeishmaelhttps://www.blogger.com/profile/16120292054853679956noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-54925759719021944402019-06-10T04:49:37.049-04:002019-06-10T04:49:37.049-04:00These cats and dogs here are indeed so cute.
Mayb...<a href="https://books.google.de/books?id=JEApDwAAQBAJ&pg=PT317&lpg=PT317&dq=%22Alice+and+Bob%E2%80%99s+boxes+are+wired+together+so+that+they+can+communicate:+the+input+to+one+can+affect+the+output+to+the+other.%22" rel="nofollow">These cats and dogs here</a> are indeed so cute. <br />Maybe QM does not use PR boxes, because it is not only about sharing information but mainly about Reimondhttps://www.blogger.com/profile/04669340425105889539noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-39461140462228199032019-06-10T03:49:36.900-04:002019-06-10T03:49:36.900-04:00My own consideration on books like these is to loo...My own consideration on books like these is to look inside and see if they have at least a sufficiently complete treatment of sum-over-histories in the mix with their other content, at the level of, for example*, Fay Dowker and Rafael D. Sorkin. If they don't, I don't have any interest in reading them.<br /><br />* Hilbert Spaces from Path Integrals<br />Fay Dowker, Steven Johnston, Philip Thrifthttps://www.blogger.com/profile/03021615111948806998noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-24249286810359852642019-06-10T02:07:57.522-04:002019-06-10T02:07:57.522-04:00Peter,
To say the obvious, the best way to answer...Peter,<br /><br />To say the obvious, the best way to answer your question is to read Ball's book. I don't mean anything deep, just that the Copenhagen people didn't exactly write down a clear definition, and no one really knows what Bohr was talking about anyways. So if you ask three physicists what the Copenhagen interpretation is, you'll get four answers. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-36177969507422457342019-06-09T23:04:51.449-04:002019-06-09T23:04:51.449-04:00There are 3 views of QM: philosophical, mathematic...There are 3 views of QM: philosophical, mathematical and physical. The interpretations are philosophical. Hamiltonian, groups, wave function, Hilbert spaces are mathematical. The experimental results are physical. We say we understand QM when we can match observations and calculations. It doesn’t mean we know the Truth because different mathematical formulations can describe the same set of Enricohttps://www.blogger.com/profile/11062542721973950650noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-23170423350045341122019-06-09T21:47:19.099-04:002019-06-09T21:47:19.099-04:00off topic, but ethan siegal is crowing the triump ...off topic, but ethan siegal is crowing the triump of dark matter over mond here, and how the bullet cluster is re-examine to support dark matter, he acknowledge about the speed of collision which is attributed to magnetic fields here<br /><br />https://www.forbes.com/sites/startswithabang/2019/06/06/scientists-discover-spaces-largest-intergalactic-bridge-solving-a-huge-dark-matter-puzzle/?neohttps://www.blogger.com/profile/16769182614452171312noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-70520744887466392592019-06-09T17:53:28.514-04:002019-06-09T17:53:28.514-04:00OK, a quick read of the first 1/3 of the book conf...OK, a quick read of the first 1/3 of the book confirms a suspicion of mine about human nature: We are a very noisy species. Sometimes out of that noise, pristine clarity emerges... and sometimes not. Quantum remains in the "not" column.Terry Bollingerhttps://www.blogger.com/profile/03915136249111338024noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-84578476076168748462019-06-09T17:28:44.737-04:002019-06-09T17:28:44.737-04:00Good review. I don't usually buy pop-q books e...Good review. I don't usually buy pop-q books either -- I recommend Feynman's QED to folks instead -- but your description makes this one sound (maybe?) worthwhile. The $$-sound is some cash landing in Philip Ball's Amazon account... :)Terry Bollingerhttps://www.blogger.com/profile/03915136249111338024noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-89208875719977535702019-06-09T07:16:46.034-04:002019-06-09T07:16:46.034-04:00Dr. Hossenfelder: Your work is mentioned in this p...Dr. Hossenfelder: Your work is mentioned in this post.<br /><br />David Brown: Although MOND would modify gravity, it would only do so at galaxy scale distances; even on our solar scale and laboratory scale we need no change to our existing models of gravity. So the modification you are talking about has nothing to say about quantizing gravity, which is the only way a new theory of gravity would Dr. A.M. Castaldohttps://www.blogger.com/profile/17988116835722393503noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-33284547138843518172019-06-09T03:34:35.966-04:002019-06-09T03:34:35.966-04:00A weird duck in the icehole seems an apt way of pu...A weird duck in the icehole seems an apt way of putting it.martenhttps://www.blogger.com/profile/02423871089614417690noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-69284401098593542262019-06-09T03:06:51.837-04:002019-06-09T03:06:51.837-04:00Forgive me, but I feel "there isn’t really su...Forgive me, but I feel "there isn’t really such a thing as the Copenhagen interpretation" is one of those true but not very helpful things that experts like to say. <br /><br />For example, this is in the Encyclopedia Brittanica: "Bohr's viewpoint, which became known as the Copenhagen interpretation of quantum mechanics, was that reality can be ascribed only to a measurement.&Jeffhttps://www.blogger.com/profile/06140726210295297492noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-44758160807874274752019-06-08T12:26:30.579-04:002019-06-08T12:26:30.579-04:00I too just finished Ball's book and am still s...I too just finished Ball's book and am still sorting out my thoughts about it, but I'd certainly recommend it to anyone who is already somewhat familiar with the subject. It's refreshingly non-polemical, doesn't shy away from asking all the hard questions, and doesn't get bogged down in historical disputes over exactly what some dead guy meant when he said such-and-such.<br />Dan S.https://www.blogger.com/profile/13437237801383466177noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-18793340745860139782019-06-08T12:22:17.058-04:002019-06-08T12:22:17.058-04:00Could you help me understand and flesh this out a ...Could you help me understand and flesh this out a little? Or is it just superposition?<br /><br />"....there isn’t really such a thing as the Copenhagen interpretation), and, best of all, clears out the idea that many worlds solves the measurement problem (it does not).<br /><br />In Ball’s book, you will learn just what quantum mechanics is (uncertainty, entanglement, superpositions, (de)PeterO73https://www.blogger.com/profile/01144387828286661393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-42420742830957116412019-06-08T10:58:11.524-04:002019-06-08T10:58:11.524-04:00Thanks so much for this Sabine. I'm glad it mo...Thanks so much for this Sabine. I'm glad it mostly worked for you. It's a funny thing about the PR box (cats and dogs) analogy. When Sandu Popescu explained this to me (without cats & dogs, but same thing), a penny really dropped for me about how the issue was related to sharing of information - and how one could formulate a Bell experiment in these terms in a way that added a fresh Philip Ballhttps://www.blogger.com/profile/09986655706443117158noreply@blogger.com