tag:blogger.com,1999:blog-22973357.post2756795155927804348..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: Physics and PhilosophieSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger88125tag:blogger.com,1999:blog-22973357.post-39837689566806149602011-08-29T09:30:25.997-04:002011-08-29T09:30:25.997-04:00It is always interesting to me how complexity aris...It is always interesting to me how complexity arises out of simplicity? :)<br /><br /><i>Investigation of quantum entanglement is currently a very active area. Research is being done on measures for quantifying entanglement precisely, on entanglement of many-particle systems, and on manipulations of entanglement and its relation to thermodynamics.</i> See:<a href="http://cam.qubit.org/node/43" PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-12763840842816889192011-08-29T09:19:21.345-04:002011-08-29T09:19:21.345-04:00Hmmmmm...
A quantum view of a Classical world?Hmmmmm...<br /><br />A quantum view of a Classical world?PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-76095922654267269722011-08-29T09:16:41.043-04:002011-08-29T09:16:41.043-04:00Phil,
Thanks for Bell's "Against Measure...Phil,<br /><br />Thanks for Bell's "Against Measurement". Merits a discussion but later. <br /><br />One thing struck me: "Landau-Lifshitz emphasize, following Bohr, that quantum mechanics requires for its formulation "classical concepts"...."<br /><br />Well, space is the first of these. In the context of non-relativistic quantum mechanics, I don't think weArunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8677563213199235622011-08-29T08:22:15.777-04:002011-08-29T08:22:15.777-04:00Michael Gogins,
Physicalism, mechanism, computati...Michael Gogins,<br /><br /><i>Physicalism, mechanism, computationalism all assume that underlying this unreasonably effective program of human thought is some Turing machine. If there were, we would not be able to identify it. If there were not, we would not be able to prove it.</i><br /><br />A foundational basis of knowledge can exemplify how one may look a the world?<br /><br />Any thoughts PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-51393660205579202632011-08-27T12:40:23.727-04:002011-08-27T12:40:23.727-04:001. The human knowledge limit is given with stabili...1. The human knowledge limit is given with stability of the part of Universe, where we are living in.<br />2. Because the time is defined so. We are livin in random Universe, the direction in which it doesn't change is considered a space, the direction in which it changes in most pronounced way it's called a time.<br />3. AWT considers Universe is random gas and everything else can be Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-53623775512206289752011-08-26T10:09:07.520-04:002011-08-26T10:09:07.520-04:00If there were true, fundamental limits to what we ...If there were true, fundamental limits to what we could know, we would not be able to know what they are.<br /><br />That means, we cannot know whether there is or is not a fundamental theory. However, scientists must of course bet that there is, and that they can learn what it is.<br /><br />Goedel's dilemma, MacKay's logical indeterminacy of a free choice, Bringsjord's appeal to theMichael Goginshttps://www.blogger.com/profile/07300917064580760923noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-25294600805277007072011-08-26T09:42:58.563-04:002011-08-26T09:42:58.563-04:00Ramond should read John M. PierreRamond should read John M. PierrePlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-29743559097012917452011-08-26T09:37:18.467-04:002011-08-26T09:37:18.467-04:00Thank you Eric for your kind words.
As a layman ...Thank you Eric for your kind words.<br /><br /> As a layman I have been following those who know what string theory is about so as to get a better understanding, yet, I am far from understanding the full scope of the subject myself.<br /><br />Goitis, I want to thank you as well. <br /><br /><br /><a href="http://1.bp.blogspot.com/-I-cX71ReRzA/Tfki615hzXI/AAAAAAAACqU/Ka2o8w1IAtQ/s1600/PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-20834425045123415132011-08-26T07:28:34.058-04:002011-08-26T07:28:34.058-04:00Hi Arun,
I could attempt to explain why ‘measurem...Hi Arun,<br /><br />I could attempt to explain why ‘measurement’ should not be part of the formulation of fundamental theory and also why other words such as “apparatus, environment, microscopic, macroscopic, reversible, irreversible, observable, and information” should also be so excluded, yet I would be just echoing a conviction grounded in logic expressed more than 21 years ago which still Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-59081133676194709542011-08-25T14:06:36.151-04:002011-08-25T14:06:36.151-04:00Hi Plato,
Yes AdS/CFT is not used only in QGP but...Hi Plato,<br /><br />Yes AdS/CFT is not used only in QGP but also to study space-like singularities like the ones you found in the interior of a black hole or in the big bang. In this case by examining how the weakly coupled dual field theory behaves when the bulk develops the singularity they are trying to qualitatively understand the nature of the singularity. As far as I know though this kind Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-89624285655784489092011-08-25T13:15:35.161-04:002011-08-25T13:15:35.161-04:00An additional question of interest, one that has a...An additional question of interest, one that has an ontological aspect, would be that of identifying examples in which dynamic organizing principles at the quantum level of description are found to “percolate” upward and reveal themselves as phenomenon at the macroscopic, work-a-day world level. The example that comes to mind is that of John Scott Russell’s “solitary wave” which was first viewed Don Fosterhttps://www.blogger.com/profile/04814669413022486958noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-42465425353286940442011-08-25T12:49:05.197-04:002011-08-25T12:49:05.197-04:00Plato, you bring up many good points. I'm afra...Plato, you bring up many good points. I'm afraid you have me at a disadvantage when talking about the intricacies. I would really have to study string theory to carry on an intelligent conversation with you about it. That I haven't done. But we all have our centers of expertise that we know a lot about, or at least more than our close acquaintances. That is something I would never Erichttps://www.blogger.com/profile/08213251864943443334noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-15547959575362886312011-08-25T09:52:31.041-04:002011-08-25T09:52:31.041-04:00Phil,
How is one to relate the mathematics of a p...Phil,<br /><br />How is one to relate the mathematics of a physical theory to the physical world, without "apparatus", "experiment", "measurement", etc.?<br /><br />-ArunArunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-54494607057497513432011-08-25T09:46:12.596-04:002011-08-25T09:46:12.596-04:00Christine,
So yes, I mean von Neuman entropy. (I&...Christine,<br /><br />So yes, I mean von Neuman entropy. (I'm very poor at remembering names associated with concepts. I guess it comes from having learned some mathematics from Soviet textbooks, where Gauss was replaced by Ostrogradsky and so on.)<br /><br />-ArunArunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-40098254577490768752011-08-25T09:30:15.675-04:002011-08-25T09:30:15.675-04:00Hi Christine,
I mean if the universe is described...Hi Christine,<br /><br />I mean if the universe is described by a density matrix ρ then in the usual double slit experiment or other experiment, Trace( ρ log(ρ))changes. Can we do measurements without a change?<br /><br />Hi Phil,<br />Can you explain more why "measurement" is not part of any fundamental physical theory?<br /><br />I happen to think it has to be.<br /><br />-ArunArunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-82897052877144955072011-08-25T09:17:29.123-04:002011-08-25T09:17:29.123-04:00Hello Eric,
Just curious how you wipe out a model...Hello Eric,<br /><br />Just curious how you wipe out a model for understanding by attaching the word string theory?:)<br /><br />Historically I have demonstrated how Lee Smolin himself tried to explain "the Thing."<br /><br />You see, it is a method by which to attempt to explain what is going on inside the black hole?<br /><br />Consider this for a second.<br /><br />I linked a "PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8125686528678451522011-08-24T16:56:58.402-04:002011-08-24T16:56:58.402-04:00I should add that my understanding is that the geo...I should add that my understanding is that the geometry of the halo around galaxies is produced by subtracting the actual measurement of light being bent coming from outside each galaxy to the amount that light should be bend from the known distribution of nucleons in the galaxy.<br /><br />Bee, if I'm incorrect in how they calculate the galactic halo maybe you could weigh in, or even if I&#Erichttps://www.blogger.com/profile/08213251864943443334noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-48622053892235169552011-08-24T16:32:52.291-04:002011-08-24T16:32:52.291-04:00This comment has been removed by the author.Erichttps://www.blogger.com/profile/08213251864943443334noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-37292508859413221212011-08-24T16:01:30.482-04:002011-08-24T16:01:30.482-04:00Plato, you have once again come through with refer...Plato, you have once again come through with references. But as I remember more about the talk that Steven Weinberg gave at CERN his final conclusion was string theory may not be the correct theory. That asymptotic safety and confinement may it.<br /><br />Of course that is one man's opinion. But I happen to share it. Also I don't know how Ads cft fits in string theory or if it requires Erichttps://www.blogger.com/profile/08213251864943443334noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-60172510304818730342011-08-24T10:23:35.435-04:002011-08-24T10:23:35.435-04:00Last link for Juan Maldacena did not work, pic mig...Last link for <a href="http://www.sns.ias.edu/~malda/nature6-12-03.pdf" rel="nofollow">Juan Maldacena</a> did not work, <a href="http://www.nature.com/nature/journal/v423/n6941/images/423695a-f1.0.jpg" rel="nofollow">pic</a> might be more useful for people here now? Look carefully:)<br /><br />Best,<br /><br /><br />http://www.sns.ias.edu/~malda/nature6-12-03.pdfPlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-57659298933077169542011-08-24T10:16:05.910-04:002011-08-24T10:16:05.910-04:00This comment has been removed by the author.PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-57877801120750390812011-08-24T10:01:36.255-04:002011-08-24T10:01:36.255-04:00Juan Maldacena:The strings move in a five-dimensio...<a href="http://www.nature.com/nature/journal/v423/n6941/full/423695a.html;jsessionid=AA09912C40810B705B2CE65ABC4DE672" rel="nofollow">Juan Maldacena</a>:<i>The strings move in a five-dimensional curved space-time with a boundary. The boundary corresponds to the usual four dimensions, and the fifth dimension describes the motion away from this boundary into the interior of the curved space-time. PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-66487680162568430482011-08-24T09:55:38.956-04:002011-08-24T09:55:38.956-04:00Holography encodes the information in a region of ...<i>Holography encodes the information in a region of space onto a surface one dimension lower. It sees to be the property of gravity, as is shown by the fact that the area of the event horizon measures the number of internal states of a blackhole, holography would be a one-to-one correspondance between states in our four dimensional world and states in higher dimensions. From a positivist PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-51654836265799210752011-08-24T09:32:56.782-04:002011-08-24T09:32:56.782-04:00Thank you Goitis and Bee for the exchanges on 8?:)...Thank you Goitis and Bee for the exchanges on 8?:)<br /><br /><a href="http://asymptotia.com/2011/08/04/heretic/" rel="nofollow">Clifford</a>:<i>The point is that de Sitter is not a nice bystander at all, so why are we sure that our most basic rules of quantum theory are complete enough for the job of understanding it? (I mentioned this near the end of the discussion. The good news was that I wasPlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-10134554886641849512011-08-24T06:06:08.274-04:002011-08-24T06:06:08.274-04:00Hi Bee,
I would agree with pov but with one obje...Hi Bee, <br /><br />I would agree with pov but with one objection. When the gravitational (geometric) side is well defined at small curvatures the strongly coupled field theory is not. So what's the point of talking about a theory that is equal 'real'? We can't do physics in the strong coupling limit and we can't describe anything or make predictions. In other words we don'Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.com