tag:blogger.com,1999:blog-22973357.post9058506489078617448..comments2020-01-17T20:40:07.189-05:00Comments on Sabine Hossenfelder: Backreaction: What if the universe was like a pile of laundry?Sabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger28125tag:blogger.com,1999:blog-22973357.post-62720033474896813112016-11-07T11:27:04.461-05:002016-11-07T11:27:04.461-05:00"The mass of the Higgs is much smaller than t...<i>"The mass of the Higgs is much smaller than the Planck mass. So what? The spatial curvature of the universe is almost zero, the cosmological constant tiny, and the electric dipole moment of the neutron is for all we know absent. Why should that bother me?"</i> <br /><br />Whether or not it bothers you depends on your goal. One sense those questions are important is that they help piein skeehttps://www.blogger.com/profile/17852247942652368610noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-43736039745536846402016-09-01T01:30:34.490-04:002016-09-01T01:30:34.490-04:00Alexey,
Excuse me, I've never called anyone i...Alexey,<br /><br />Excuse me, I've never called anyone in my life a "crook" - it's a word that isn't even in my vocabulary, so please stop accusing me of things I've never done.<br /><br />I think you didn't get the point this post. It wasn't to say that a pile of laundry is a good metaphor, it was to say we all take our inspirations from simple ideas, but in theSabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-4024517021119024422016-09-01T00:36:38.169-04:002016-09-01T00:36:38.169-04:00This comment has been removed by the author.Alexey Gubinhttps://www.blogger.com/profile/13280292959375771555noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-32533556946296309912016-08-28T04:51:52.994-04:002016-08-28T04:51:52.994-04:00In a perfect rotationally symmetric washingmachine...In a perfect rotationally symmetric washingmachine universe, find a breaking symmetry mechanism that produce<br />1) a chromatic number violation for pants<br />2) a parity violation for black socksGiorgio castriota scanderbeghttps://www.blogger.com/profile/00390949260307609476noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-12937314500670260352016-08-26T10:59:26.773-04:002016-08-26T10:59:26.773-04:00@Meta Tron Given a non-commutative construct, rev...<b>@Meta Tron</b> Given a non-commutative construct, reverse the signs of one coordinate (mirror image, S_1 improper rotation axis) and all coordinates (parity inversion, S_2 improper rotation axis). Are sign-reversed constructs <i>exactly</i> superposable upon the originals? If not, non-commutative constructs are chiral.<br /><br />Chiral entities cannot possess S_n symmetries. Baryogenesis&Uncle Alhttps://www.blogger.com/profile/05056804084187606211noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-51265033077387676492016-08-26T06:50:47.520-04:002016-08-26T06:50:47.520-04:00The problem with such speculative ideas is that th...The problem with such speculative ideas is that they are not based on an experimental fact. This leads to inconsistencies as the theory is developed which unfortunately will be explained away by other speculative propositions feeding an infinite loop and diverting human and financial resources from the actual problem. This problem is becoming pandemic in fundamental physics. The firewall problem,Stuart https://www.blogger.com/profile/12767480095489975264noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-27169619984257367142016-08-26T06:24:08.862-04:002016-08-26T06:24:08.862-04:00Steven,
Well, they don't (lie in that subspac...Steven,<br /><br />Well, they don't (lie in that subspace). Really I think you should read the CDT papers I've linked to, I don't get the impression you know what you're talking about.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-42434242773170909412016-08-26T04:49:53.620-04:002016-08-26T04:49:53.620-04:00This comment has been removed by the author.Steven Sagaerthttps://www.blogger.com/profile/00342427666369346793noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-57025534670273994102016-08-26T04:15:50.150-04:002016-08-26T04:15:50.150-04:00Steven,
The paths that you talk about have dimens...Steven,<br /><br />The paths that you talk about have dimension two because they're paths of (classical) particles. If you want to know quantum properties of other things, this generally isn't the case. Eg, Causal Dynamical Triangulation uses the Feynman path integral approach, but the "paths" in this case are space-times each. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-26688121478062731292016-08-26T04:14:10.419-04:002016-08-26T04:14:10.419-04:00Bill,
In Kaluza-Klein one *adds* dimensions. You ...Bill,<br /><br />In Kaluza-Klein one *adds* dimensions. You can then make them unnoticeable by rolling them up ("compactifying") them to small radius. In this case, there will be more dimensions that become accessible at higher energy (short distances), not less. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-47665963269008387922016-08-26T03:50:03.906-04:002016-08-26T03:50:03.906-04:00This comment has been removed by the author.Steven Sagaerthttps://www.blogger.com/profile/00342427666369346793noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-3909964246018384392016-08-25T13:51:54.331-04:002016-08-25T13:51:54.331-04:00Mathematically, the progression is moving from ord...Mathematically, the progression is moving from ordinary smooth manifolds with commutative rings of functions acting locally on their spectra to noncommutative algebras acting on noncommutative spaces (that replace the familiar open sets isomorphic to R^n). This is the essence of noncommutative geometry, where Connes takes the noncommutative algebra to have the full structure of a C*-algebra. Meta Tronhttps://www.blogger.com/profile/03374351626024861978noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-2768001864549378962016-08-25T13:51:24.887-04:002016-08-25T13:51:24.887-04:00"What if the universe was like a pile of laun..."What if the universe was like a pile of laundry?"<br /><br />You would still be missing 1 sock.TheBigHenryhttps://www.blogger.com/profile/04917973198063733316noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-38566062468973065532016-08-25T13:12:19.836-04:002016-08-25T13:12:19.836-04:00No mention of Kaluza-Klein as an example of dimens...No mention of Kaluza-Klein as an example of dimensional reduction? Maybe I'm just not getting it. Anyway, love the blog and the ideas you're proposing.Billhttps://www.blogger.com/profile/13243006930165511059noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-4314544585761809512016-08-25T00:49:29.225-04:002016-08-25T00:49:29.225-04:00andrew,
To my knowledge, no. andrew,<br /><br />To my knowledge, no. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-82595300118546115002016-08-24T18:14:02.171-04:002016-08-24T18:14:02.171-04:00There also doesn't seem to be an active hyperl...There also doesn't seem to be an active hyperlink with the reference, 1304.7247, concerning the differing types of random walk, which seems to be here:<br /><br />http://arxiv.org/pdf/1304.7247.pdfWes Hansenhttps://www.blogger.com/profile/00913503952284529871noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-65352582887520599812016-08-24T17:44:57.304-04:002016-08-24T17:44:57.304-04:00Interesting piece, as always. Re taking the time o...Interesting piece, as always. Re taking the time out of spacetime are you suggesting that this step toward quantum gravity may in any way require repudiation of the spacetime notion and thus GR? Tam Hunthttps://www.blogger.com/profile/05919461715412820636noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-1742350789570281822016-08-24T15:58:03.028-04:002016-08-24T15:58:03.028-04:00No the insight is very good. It's obvious, but...No the insight is very good. It's obvious, but not pejoratively for the individual to speak first. <br />But even good insights say little about the future direction of research science. What must be true is the one that speaks there. This excerpt says the most: <br />"<i>I find it intriguing that several different approaches to quantum gravity share a behavior like this.</i>"piein skeehttps://www.blogger.com/profile/17852247942652368610noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-22583690775757889022016-08-24T15:48:39.357-04:002016-08-24T15:48:39.357-04:00Bee,
"Or against trusting a mathematical the...Bee,<br /><br />"Or against trusting a mathematical theory in the absence of observation.."<br /><br />Disagree. A mathematical theory can exist independent of observation, while an observation without theory-dependence is meaningless. Think: Penzias & Wilson and CMB. If the big bang theory of cosmology had not preceded its discovery, what would one have called the radiation butt h rayhttps://www.blogger.com/profile/00150085167540063914noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8427794198096221362016-08-24T14:07:35.145-04:002016-08-24T14:07:35.145-04:00Do either of these definitions of dimension coinci...Do either of these definitions of dimension coincide with fractal dimension?andrewhttps://www.blogger.com/profile/08172964121659914379noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-38553599699561186802016-08-24T13:38:36.511-04:002016-08-24T13:38:36.511-04:00"The shirts and towels, they’re really crinkl..."The shirts and towels, they’re really crinkled and interlocked two-dimensional surfaces." That part sounds a bit misleading because the pile is physically still 3D and the 2D surface is mathematical. I only mention this because you mention near the end, "walk in space, not space-time, and so it’s not a real physical process"; some forget to consider what can only be a Louis Tagliaferrohttps://www.blogger.com/profile/16698865662162457632noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-22061594003561190112016-08-24T13:31:46.682-04:002016-08-24T13:31:46.682-04:00"What if the universe was like a pile of laun..."<i>What if the universe was like a pile of laundry?"</i> The subjunctive case of "to be," "were like," is better.<br /><br />Running dimensionality and the Casimir effect suggest atomic force microscopy for measuring gravitation/distance. EM relative amplitude suggests otherwise. If gravitation is fractal at small separations, magnification or tessellation won&#Uncle Alhttps://www.blogger.com/profile/05056804084187606211noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-4798186283754871792016-08-24T12:53:00.569-04:002016-08-24T12:53:00.569-04:00Glenn,
Yes, that's where the link should have...Glenn,<br /><br />Yes, that's where the link should have pointed! I've fixed this now, thanks for letting me know.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-52050511434136077452016-08-24T12:38:06.034-04:002016-08-24T12:38:06.034-04:00Big Henry,
Thanks for letting me know, I've f...Big Henry,<br /><br />Thanks for letting me know, I've fixed this!Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-14464565173810174392016-08-24T12:37:51.376-04:002016-08-24T12:37:51.376-04:00t h ray,
Or against trusting a mathematical theor...t h ray,<br /><br />Or against trusting a mathematical theory in the absence of observation...Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.com