tag:blogger.com,1999:blog-22973357.post3263586412276275088..comments2020-07-12T10:17:49.861-04:00Comments on Sabine Hossenfelder: Backreaction: What is analogue gravity and what is it good for?Sabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger42125tag:blogger.com,1999:blog-22973357.post-33548485094263805432014-03-04T10:43:16.767-05:002014-03-04T10:43:16.767-05:00kashyap,
I don't have much to say about that ...kashyap,<br /><br />I don't have much to say about that because I'm not sure either. But who knows, it seems quite possible to me that there will be a mutual inspiration and exchange of tools and techniques which might or might not turn out to lead to something. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-62567293567470271292014-03-04T10:40:58.118-05:002014-03-04T10:40:58.118-05:00Giotis,
As I've said several times before, wh...Giotis,<br /><br />As I've said several times before, when I say "quantum gravity" I mean "the theory of quantum gravity" which explains certain facts about nature, eg what happens to collapsing matter, what happened in the beginning of the universe, what happens to the gravitational field of electrons going through a double slit etc. What you mean when you say "Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-36556735523283986642014-03-03T20:12:34.597-05:002014-03-03T20:12:34.597-05:00Thanks for the input Bee, didn't mean to talk ...Thanks for the input Bee, didn't mean to talk past you! <br /><br />I would definitely add that I can't really imagine anything not being amenable to mathematical description. Mathematics can be thought of more as the study of structure (as opposed to everything being built from numbers, which are simply fixed points in the structure of the natural numbers), which the universe clearly petehttps://www.blogger.com/profile/12969621709127674152noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-27648512853872829762014-03-03T12:20:19.427-05:002014-03-03T12:20:19.427-05:00Hi Bee: I am not sure how experiments or theory in...Hi Bee: I am not sure how experiments or theory in condensed matter would help high energy physics.Suppose they find monopoles,axions,Majorana fermions or even black holes (as they may have found some of these as quasi-particles already)would it make any difference as to the existence of these as actual particles at high energies? I am not even sure if such efforts have helped in finding correct Anonymoushttps://www.blogger.com/profile/10732897306667764590noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-24494116819675141012014-03-02T18:04:45.283-05:002014-03-02T18:04:45.283-05:00Giotis,
That is simply a limited view.
Many more t...Giotis,<br />That is simply a limited view.<br />Many more things in physics or math as intelligible (IFT) than by consistency.<br />Consider gluon and quark jets as influencing (TD just wrote on this). The bumps and anomalies vanish in a higher intelligible conception.<br />One can measure particles in a region of space and use statistical methods without a higher concept of gravity or what L. Edgar Ottohttps://www.blogger.com/profile/00525169618204198073noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-39594871801188552082014-03-02T17:13:53.258-05:002014-03-02T17:13:53.258-05:00“…which might be many things but not an approach t...“…which might be many things but not an approach to quantum gravity”<br />It’s definitely an approach to QG. The theory in the bulk dual to the Conformal field theory must be a consistent theory of QG since the CFT is UV complete.<br />Did you know for example that you case use AdS/CFT to understand space-like singularities in the bulk beyond the SUGRA approximation?<br />Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-80338999418567935752014-03-02T02:42:36.041-05:002014-03-02T02:42:36.041-05:00Vince,
You're confusing the value of a functi...Vince,<br /><br />You're confusing the value of a function with its derivative. Also, most of the string theorists are working on AdS/CFT, which might be many things but not an approach to quantum gravity. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-88692381535932570912014-02-28T19:23:04.587-05:002014-02-28T19:23:04.587-05:00Wes,
Let us consider there is some sort if general...Wes,<br />Let us consider there is some sort if general background. (Martin Gardner used the term Phaneron).<br />We debate, discover, or impose some sort of understanding on it and even wonder if it is there regardless of how we think about it or ourselves.<br /><br />If I map it as an invariant ordered coordinate system of crystalline pixel like regions where pixels may include issues of L. Edgar Ottohttps://www.blogger.com/profile/00525169618204198073noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-15147791041409642292014-02-28T16:51:50.396-05:002014-02-28T16:51:50.396-05:00Hi Sabine,
I'd like to illuminate one final po...Hi Sabine,<br />I'd like to illuminate one final point and I promise to shutup forever more on this blog. Non- neutral massive charges do not have linear paths through empty space. Whenever they are accelerated they deflect. This corresponds to the up-down degrees of freedom shown in the Stern-Gerlach apparatus. But a neutral massive particle made up of individual non-neutral individual Erichttps://www.blogger.com/profile/08213251864943443334noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-18189129931541034542014-02-28T15:34:28.778-05:002014-02-28T15:34:28.778-05:00Now the whole point of posting the email I sent to...Now the whole point of posting the email I sent to Kevin Knuth was to point out that mathematics, like science, is a PROCESS which includes an entity z, a proper subset of entity z called, purely for convenience, entity x, and a PROCESS y such that when entity x is applied to process y the entity z, or a reasonably close approximation thereof, results. I thoroughly understand what your post is PonderSeekDiscoverhttps://www.blogger.com/profile/00913503952284529871noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-52162994129783636782014-02-28T15:33:12.675-05:002014-02-28T15:33:12.675-05:00Sabine,
I apologize, I should have posted my comm...Sabine,<br /><br />I apologize, I should have posted my comment to the Nature=Mathematics post. I became interested in the comment which links to said post:<br /><br />“Consider that mathematics is not in fact a language able to describe all of nature. What would we do if we had reached its limits?”<br /><br />You suggest that we can use simpler systems to model, hence, distill information about,PonderSeekDiscoverhttps://www.blogger.com/profile/00913503952284529871noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-766743641256272062014-02-28T15:10:58.714-05:002014-02-28T15:10:58.714-05:00I'm not a string theorist, but I highly doubt ...I'm not a string theorist, but I highly doubt that string theory is falling out of favor. Thousands of people are still working on it.<br /><br />And I'm not expert on analogue gravity, but studying analogue gravity makes as much sense to me as using the rubber sheet analogy to study general relativity in the solar system.bobbyhttps://www.blogger.com/profile/08418289952896034658noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-5601945545147758602014-02-28T15:10:40.047-05:002014-02-28T15:10:40.047-05:00This comment has been removed by the author.bobbyhttps://www.blogger.com/profile/08418289952896034658noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-71118192187431738282014-02-28T13:50:19.065-05:002014-02-28T13:50:19.065-05:00Sabine: "I don't know how we can possibly...Sabine: "I don't know how we can possibly tell that mathematics is the ultimate and final language to describe reality."<br /><br />Let's underline that last phrase: "to describe reality."<br /><br />Seems to me that what you (we) are talking about is not simply the description of reality but the representation of reality and one should clarify that as follows: the DocGhttps://www.blogger.com/profile/17359004200002936544noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-77830777028947829362014-02-28T04:04:49.831-05:002014-02-28T04:04:49.831-05:00Pete,
Please see my reply to Wes. You're talk...Pete,<br /><br />Please see my reply to Wes. You're talking past me. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-50338134823759129712014-02-28T04:03:22.360-05:002014-02-28T04:03:22.360-05:00Wes,
You write:
"Sabine, I wholeheartedly d...Wes,<br /><br />You write:<br /><br /><i>"Sabine, I wholeheartedly disagree with you regarding mathematics! [...] I’ve spent a great deal of time meditating on this argument and if you truly understand it and its implications, there is no way you can argue that mathematics – Platonic forms – have no existence"</i><br /><br />That is almost certainly true because "existence" isSabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-11312865941691309752014-02-27T20:01:32.720-05:002014-02-27T20:01:32.720-05:00Great article,
I have to agree with Wes (though I...Great article,<br /><br />I have to agree with Wes (though I'll leave all of the mystical stuff and religious connotations out) when he talks about mathematics and its relationship with the world. I just don't see how the idea of mathematics being a "useful tool" holds any water when you see pure mathematical structures being used to predict particles years before they're petehttps://www.blogger.com/profile/12969621709127674152noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-63768777693382492142014-02-27T19:58:29.861-05:002014-02-27T19:58:29.861-05:00Eric,
I do not know which you are. I am here quite...Eric,<br />I do not know which you are. I am here quite by accident. I did not mean to interrupt the continuity of your posts.<br />Zephir 's problem I feel is not necessarily his concepts but unwarranted disrespect for Sabine 's indulgence. Sorry, if I have nothing to share with you. But make no mistake, with the honor to be here with care for foundations and frontiers one day you may L. Edgar Ottohttps://www.blogger.com/profile/00525169618204198073noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-20688009104598650932014-02-27T19:26:21.679-05:002014-02-27T19:26:21.679-05:00Otto, yes you like to talk, and you do it very wel...Otto, yes you like to talk, and you do it very well. But I think rather than actually listening or absorbing info you are always thinking about what you are going to say next. I've found that many people are like you in that they enjoy being annoying and content free... either saying meaningless drivel or repeating the same thing over and over again, ad infinitum. That's why I no longer Erichttps://www.blogger.com/profile/08213251864943443334noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-2052817316136927242014-02-27T19:17:05.881-05:002014-02-27T19:17:05.881-05:00Eric,
Pardon my thought experiment.
There is s big...Eric,<br />Pardon my thought experiment.<br />There is s big difference between dimensionless and dimensions.<br />Also between meaningless and meaning free.<br />I would welcome being convinced by your view if I did not think it a logical but coincidental case. Maybe my mind is just a non linear stray voltage accelerator afterall, luck if the draw in some jumbled analog of cosmic rays and L. Edgar Ottohttps://www.blogger.com/profile/00525169618204198073noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-57308914963505988172014-02-27T18:30:43.794-05:002014-02-27T18:30:43.794-05:00The interesting part of this whole discussion is w...The interesting part of this whole discussion is when you accelerate a subatomic massive particle. Photons are known to have their spin plane orthogonal to any acceleration. They have left and right circular polarization - that's it. So their degrees of freedom would agree with the fact that they do not have the Higgs. There spin plane does not bend into the direction of acceleration.<br /><Erichttps://www.blogger.com/profile/08213251864943443334noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-75381898935639841772014-02-27T18:13:52.060-05:002014-02-27T18:13:52.060-05:00The Lorentz Force equation in an organized electro...The Lorentz Force equation in an organized electromagnetic field is<br /> <br />F = q(E + V X B)<br /><br />If we transform those motions to the first derivative of the original the equation changes to<br /><br />F = q(E + A X B)<br /><br />I simplified the E side because in a truly random field everywhere is an inertial reference when moving at constant velocity. It wouldn't essentially Erichttps://www.blogger.com/profile/08213251864943443334noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-28185829943372142522014-02-27T17:59:15.434-05:002014-02-27T17:59:15.434-05:00Wes,
I certainly praise the depth of your comments...Wes,<br />I certainly praise the depth of your comments.<br /><br />By their fruits you shall know them<br />Not a sparrow falls that X does not know it as if to supply a landscape of meaning.<br />Apples start as pairs, one falls, the other grows. The mythical one that fell on Newton's head did not knock him out but upon awakening in the real positive solid world he saw at first an afterglowL. Edgar Ottohttps://www.blogger.com/profile/00525169618204198073noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-62143391565687024102014-02-27T17:53:37.919-05:002014-02-27T17:53:37.919-05:00The degrees of freedom of the electromagnetic forc...The degrees of freedom of the electromagnetic force in the macroscopic world is the Lorentz Force. What is unspoken, and unnoticed, is that the electromagnetic forces derived in the Lorentz Force equation come from an ORGANIZED electromagnetic field. In other words, previous accelerations of charges that have still left their effects are used to model the electromagnetic fields. Perhaps we can Erichttps://www.blogger.com/profile/08213251864943443334noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-85090566595007695712014-02-27T17:38:48.793-05:002014-02-27T17:38:48.793-05:00Hi Sabine,
I think this is a category of physics t...Hi Sabine,<br />I think this is a category of physics that is ripe for the plucking. In fact, I think we can do better than just use macroscopic analogues to model gravity, though I think that is useful. A good way to organize one's thoughts is to categorize forces, including gravity, according to the level of organization of the underlying substance, whatever that is. This has deep Erichttps://www.blogger.com/profile/08213251864943443334noreply@blogger.com