tag:blogger.com,1999:blog-4637778157419388168.post8810713979624603351..comments2024-03-21T09:01:08.175-07:00Comments on Physics with an edge: Critique of Verlinde's GravityMike McCullochhttp://www.blogger.com/profile/00985573443686082382noreply@blogger.comBlogger22125tag:blogger.com,1999:blog-4637778157419388168.post-79960194207185546572019-04-29T19:20:23.916-07:002019-04-29T19:20:23.916-07:00The math Verlinde uses seems sloppy to me. I coul...The math Verlinde uses seems sloppy to me. I couldn't make any sense out of his entropy formulas--the units didn't seem to match anything resembling entropy. It's kind of like he decided, "This is going to be entropy, OK?"GM Jacksonhttps://www.blogger.com/profile/02363192260461368016noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-1282447437449135972017-05-12T01:55:14.001-07:002017-05-12T01:55:14.001-07:00The gravity of star is researched by earth measu...The <a href="http://earthmeasured.com/contact-us/" rel="nofollow"> gravity</a> of <a href="http://earthmeasured.com/contact-us/" rel="nofollow"> star</a> is researched by earth measured and also described in and <a href="http://earthmeasured.com/contact-us/" rel="nofollow"> Ezekiel </a> abhishek manehttps://www.blogger.com/profile/16652710713666252839noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-50359111233871618882017-02-21T07:13:06.001-08:002017-02-21T07:13:06.001-08:00I want to understand why physicist Erik Verlind al...I want to understand why physicist Erik Verlind along with physicist Sabine Hossenfelder insist on affirming that there is emerging gravitation, why ?. After all the test performed with "gravitational lenses" belong to General Relativity. Why did Erik Verlind appropriate or steal the Mond Theory?<br />Anonymoushttps://www.blogger.com/profile/02307204255190812419noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-43391922665651947172017-01-02T17:07:11.726-08:002017-01-02T17:07:11.726-08:00Perspective on MOND emergence from Verlinde's ...<a href="https://arxiv.org/abs/1612.09582" rel="nofollow">Perspective on MOND emergence from Verlinde's "emergent gravity" and its recent test by weak lensing</a>Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-61610929273728304162016-12-22T07:25:03.701-08:002016-12-22T07:25:03.701-08:00Zephir: Good question. That's on my to-do list...Zephir: Good question. That's on my to-do list.Mike McCullochhttps://www.blogger.com/profile/00985573443686082382noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-45908553790746650892016-12-21T10:31:40.319-08:002016-12-21T10:31:40.319-08:00Verlinde's emergent gravity vs MOND and the ca...<a href="https://arxiv.org/abs/1612.06282v1" rel="nofollow">Verlinde's emergent gravity vs MOND and the case of eight dwarf spheroidals</a> For a point particle, or outside an extended spherically symmetric massive object, Milgrom's empirical fitting formula is recovered. However, Verlinde's theory departs from MOND when considering the inner structure of galaxies. I'd interested, how the MiHsC theory would handle it.Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-13866249785750027192016-12-12T12:54:27.831-08:002016-12-12T12:54:27.831-08:00First test of Verlinde's theory of Emergent Gr...<a href="https://arxiv.org/abs/1612.03034" rel="nofollow">First test of Verlinde's theory of Emergent Gravity using Weak Gravitational Lensing measurements</a> <br /><br /> versus<br /> <br /> Wang, Tower. "Modified entropic gravity revisited". <a href="https://en.wikipedia.org/wiki/ArXiv" rel="nofollow">arXiv</a>:<a href="https://arxiv.org/abs/1211.5722" rel="nofollow">1211.5722</a>, Kobakhidze, Archil. "Gravity is not an entropic force".<br /> <a href="https://en.wikipedia.org/wiki/ArXiv" rel="nofollow">arXiv</a>:<a href="https://arxiv.org/abs/1009.5414" rel="nofollow">1009.5414</a>, Kobakhidze, Archil. "Once more: gravity is not an entropic force".<br /> <a href="https://en.wikipedia.org/wiki/ArXiv" rel="nofollow">arXiv</a>:<a href="https://arxiv.org/abs/1108.4161" rel="nofollow">1108.4161</a>.<br /><br />Why <a href="http://www.technologyreview.com/view/425220/experiments-show-gravity-is-not-an-emergent-phenomenon/" rel="nofollow">the theories, which failed already are tested again?</a><br /><br />@McCulloch: IMO just the usage of integral factor (co-moving cosmic diameter) rather than running value (product of Hubble constant and speed of light) makes the estimation of quantum effects with MiHsC more precise than with MOND. Technically, the MOND should be more exact for very lightweight dark matter, but this matter exhibits filaments between galaxies, for which the holographic models generally work better, than any modifications of relativity (which lead to spherical symmetry of dark matter around massive bodies in general).Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-66125561343599073652016-12-11T09:24:41.246-08:002016-12-11T09:24:41.246-08:00Zephir: I now use Theta = 8.8x10^26m which is the ...Zephir: I now use Theta = 8.8x10^26m which is the co-moving cosmic diameter, ie: the diameter now, rather than the diameter when the light was emitted.Mike McCullochhttps://www.blogger.com/profile/00985573443686082382noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-50936693424659237732016-12-07T13:05:43.378-08:002016-12-07T13:05:43.378-08:00BTW MiHsC also uses diameter of observable Univers...BTW MiHsC also uses diameter of observable Universe for it - how this value is determined? Being an integral quantity of the red shift, it could explain, why MiHsC gives slightly better predictions than MOND.Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-45754286847025637162016-12-07T13:00:50.801-08:002016-12-07T13:00:50.801-08:00The epicycles had low adjustability, as they were ...The epicycles had low adjustability, as they were tightly fitted to experimental data. They enabled to predict solar eclipses with high precision (few hours). MiHsC doesn't predict 153 galaxies, it predicts their rotational acceleration from observable mass.Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-74675247108365177422016-12-04T13:36:44.808-08:002016-12-04T13:36:44.808-08:00Zephir: MiHsC is infinitely better than the epicyc...Zephir: MiHsC is infinitely better than the epicycles because it has zero adjustability, the epicycles had huge adjustability. Verlinde's stuff is extremely complex, has a huge number of assumptions and is never compared with any data. It is falsified because it cannot explain dwarf galaxies. In contrast MiHsC predicts the 153 galaxies in the SPARC catalogue exactly, including dwarfs, without any adjustment, and it is a simple as you can get.Mike McCullochhttps://www.blogger.com/profile/00985573443686082382noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-49607562811633722762016-12-04T08:58:42.188-08:002016-12-04T08:58:42.188-08:00BTW How the MiHSC theory accounts to the fact, tha...BTW How the MiHSC theory accounts to the fact, that some galaxies poor of dark matter, whereas some others have surprisingly high content of dark matter? The holographic model holds somewhat stronger position here, as it allows the dark matter to depend on the amount of matter in their neighborhood. Of course I'm aware that it occasionally would fail just from the same reason, but still...Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-82588904914287485112016-12-04T07:14:28.431-08:002016-12-04T07:14:28.431-08:00The general socio-psychological principles, which ...The general socio-psychological principles, which kept the epicycle model and stringy/susy models in the game long after these models were disproved by observations are the same, only people involved changed. But once you'll establish larger group of sympathizers around your theory, you'll face similar problem like the epicycle theory: the formal agreement of theory with experiments still doesn't imply, that the underlying physical mechanism cannot be different.<br /><br />As for latest Verlinde's model, it's based on projective holographic geometry more, than on emergent mechanism. If you remember what I criticized about your theory (i.e. the explanation of very local effects with very distant ones), then exactly the same could be applied to Verlinde theory also. In this respect your theory shares more common aspects with Verlinde model, than you may be probably willing to admit in a given moment... ;-)Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-348304898406212052016-12-02T01:14:37.777-08:002016-12-02T01:14:37.777-08:00Zephir: The way you describe it, it sounds like an...Zephir: The way you describe it, it sounds like an priesthood where you have to memorise complex texts to gain admittance and lay people then dutifully stand back in awe.. Yes, that sounds like the mainstream :) As for me, I'd like to know the real answer, and I have no desire to join such a group.Mike McCullochhttps://www.blogger.com/profile/00985573443686082382noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-611104992689918112016-12-02T01:05:21.045-08:002016-12-02T01:05:21.045-08:00David: Complexity is not impressive in science, si...David: Complexity is not impressive in science, simplicity is.Mike McCullochhttps://www.blogger.com/profile/00985573443686082382noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-1227837360243510952016-12-01T17:05:57.597-08:002016-12-01T17:05:57.597-08:00/* MiHsC is simple. Emergent gravity is complex an.../* MiHsC is simple. Emergent gravity is complex and Byzantine */<br /><br />Why not to learn from recent past of stringy/susy models (theory is too strong word here)? The complex and opaque models provide the occupation for more theorists, the larger groups of theorists is more loud and influential in their promotion. Occupational circle gets closed. Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-65399250579608906652016-11-26T15:56:48.876-08:002016-11-26T15:56:48.876-08:00Reading Erik Verlinde's paper, or I should say...Reading Erik Verlinde's paper, or I should say attempting to read it, makes me appreciate the extraordinary intelligence of some people; how they can take so many disparate concepts and weave them into what appears to be a coherent whole. I'm glad you provided an overview, to save me from a brain meltdown!David Schroederhttps://www.blogger.com/profile/18048116250413347228noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-8754507480438960702016-11-19T21:50:53.910-08:002016-11-19T21:50:53.910-08:00The recent emdrive paper from NASA was the proxima...The recent emdrive paper from NASA was the proximate reason for me mentioning the Bohmian interpretation, yes, though the Couder oil pan experiments are fascinating and convincing evidence for the pilot wave interpretation, or at least evidence for some QM variant beyond the Copenhagen interpretation. The Copenhagen interpretation has long struck me as far too metaphysical for its own good. <br /><br />Looking forward to reading your own work when it busts past the gatekeepers. They can't hold it back much longer. :) Anonymoushttps://www.blogger.com/profile/02549544553593188675noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-78862072896851543352016-11-19T02:49:49.992-08:002016-11-19T02:49:49.992-08:00Duane. Well, I don't accept either of those QM...Duane. Well, I don't accept either of those QM interpretations. I have an informational interpretation of quantum mechanics that I think is better and that I am trying to publish (I've submitted it 4 times so far). It is testable.. I guess you are referring to the NASA EW hypothesis for the emdrive. I looked through it last year and, although I admire those EW guys for the experiments they do, I'm afraid I don't believe their hypothesis (at least, the version I saw last year) since there were too many arbitrary adjustable parameters (they had 3), too much was hidden in complex computer modelling, their 'acoustic vacuum' model appeared contrived and in my opinion would produce a different kind of nature to the one we see.Mike McCullochhttps://www.blogger.com/profile/00985573443686082382noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-35740411579169534572016-11-18T20:28:43.635-08:002016-11-18T20:28:43.635-08:00Oddball Query. Can MiHsC survive "transplanta...Oddball Query. Can MiHsC survive "transplantation" from Copenhagen Interpretation QM to Bohmian/ pilot wave QM?Anonymoushttps://www.blogger.com/profile/02549544553593188675noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-82308791261508010072016-11-15T11:45:55.042-08:002016-11-15T11:45:55.042-08:00Mike - Brlliant! I hope you put your critique wher...Mike - Brlliant! I hope you put your critique where it belongs in the discussion of the paper! IANAS (I Am Not A Scientist) so I don't (yet) know where to look to check for it.Andrew Jaremkohttps://www.blogger.com/profile/07781060305332803073noreply@blogger.comtag:blogger.com,1999:blog-4637778157419388168.post-16294745880569841632016-11-13T00:20:52.703-08:002016-11-13T00:20:52.703-08:00Totally missed that refutation of Verlinde. Thanks...Totally missed that refutation of Verlinde. Thanks Mike!qraalhttps://www.blogger.com/profile/13436948899560519608noreply@blogger.com