tag:blogger.com,1999:blog-22973357.post8366826206186145183..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: The Planck length as a minimal lengthSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger31125tag:blogger.com,1999:blog-22973357.post-57762545326675204352012-08-24T11:34:37.210-04:002012-08-24T11:34:37.210-04:00About the speed of light limit. I would like to sa...About the speed of light limit. I would like to say that in multitemporal relativities in which other speeds of light could appear (I know, it is a crazy idea, there is no evidence of that although DM/DE are puzzling too, and people usually argue hardly against multitime theories and other geometries beyond the riemannian one), and other extensions of relativistic symmetries, the limit is no Jhttps://www.blogger.com/profile/01942050607289418780noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-84677272703325285892012-02-02T17:21:01.508-05:002012-02-02T17:21:01.508-05:00I guess patience is a virtue.I guess patience is a virtue.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-19134841807215422762012-01-29T09:30:39.520-05:002012-01-29T09:30:39.520-05:00Just as exceeding the speed of light is "impo...Just as exceeding the speed of light is "impossible" because it would turn time "inside out," so exceeding the Plank length limit is "impossible" because it would turn space "inside out." So maybe this is where we need to look when we look for those tiny, curled up "extra dimensions."DocGhttps://www.blogger.com/profile/17359004200002936544noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-35479366885074433512012-01-28T10:51:24.524-05:002012-01-28T10:51:24.524-05:00L.H. Thomas used something Frame like to analyze t...L.H. Thomas used something Frame like to analyze the precession of the electron, parallel transported around an orbit, so something is not quite a geometrical point. Perhaps one might argue that quanta are more fundamental than idealized spacetime geometry, but merely consistent with it.joel ricehttps://www.blogger.com/profile/06048310899055838262noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-87600443996513724062012-01-27T15:20:10.245-05:002012-01-27T15:20:10.245-05:00http://physicsforme.wordpress.com/2012/01/22/are-o...http://physicsforme.wordpress.com/2012/01/22/are-opera-neutrinos-faster-than-light-because-of-non-inertial-reference-frames/Ullahttps://www.blogger.com/profile/16634036177244152897noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-67475897629597081732012-01-27T08:40:57.342-05:002012-01-27T08:40:57.342-05:00In dense aether model the observable reality appea...In dense aether model the observable reality appears like fractal landscape under the fog (or like the undulating water surface being observed via its own ripples). The density fluctuations of dark matter replicate the foamy structure of space-time at short scales (Higgs field). After then two AdS/CFT dual approaches could be applied here:<br /><br />1) Nothing smaller than these density Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-67942233812068500632012-01-27T02:26:47.863-05:002012-01-27T02:26:47.863-05:00Does lightphotons and neutrinos interact at all? N...Does lightphotons and neutrinos interact at all? Neutrinos are still leptons?<br /><br />At c does the photon behave relativistic also then? A photon is massless. c is measured by em-force as Uncle Al points out. You say Planck energy is always higher.Ullahttps://www.blogger.com/profile/16634036177244152897noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-53365778256039427032012-01-27T01:39:59.701-05:002012-01-27T01:39:59.701-05:00Hi Genorb,
Thanks! That is very useful. Best,
B....Hi Genorb,<br /><br />Thanks! That is very useful. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-77617890689019445682012-01-26T22:08:39.469-05:002012-01-26T22:08:39.469-05:00Hi Bee,
It’s indeed interesting to wonder what if...Hi Bee,<br /><br />It’s indeed interesting to wonder what if anything can be defined as the minimum of length and yet as J.S. Bell would point out quite another thing to consider what exactly it is we are attempting to have measured as to be so defined.<br /><br /><i><b>“The concept of 'measurement' becomes so fuzzy on reflection that it is quite surprising to have it appearing in Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-45727742259833458462012-01-26T12:20:50.803-05:002012-01-26T12:20:50.803-05:00Given frequency, wavelength inversely varies with ...Given frequency, wavelength inversely varies with refractive index. Anomalous dispersion reduces local speed of light to 340 m/s (ruby), to 17 meters/sec (BEC), and to zero. Electromagnetic Planck length may suffer interaction wildly altering scale. Gravitation is interaction. Equivalence Principle (EP) composition, field, and photon tests are inert to 5x10^(-14) difference/average. Physics Uncle Alhttps://www.blogger.com/profile/05056804084187606211noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-2031744654841272832012-01-26T08:17:33.415-05:002012-01-26T08:17:33.415-05:00Hi All,
Mead Article
This link expires in 10 d...Hi All,<br /><br /><a href="https://fichiers.umons.ac.be/download.php?id=NzoRjEJbggqRb2Bx#mead-article.pdf" rel="nofollow"> Mead Article </a><br /><br />This link expires in 10 days.<br /><br />Best wishesGenorbhttps://www.blogger.com/profile/01431685127319958296noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-47911782037141222812012-01-26T08:14:25.992-05:002012-01-26T08:14:25.992-05:00This comment has been removed by the author.Genorbhttps://www.blogger.com/profile/01431685127319958296noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-82286242718330524312012-01-26T07:50:58.481-05:002012-01-26T07:50:58.481-05:00Hi Juan,
Unfortunately, I cannot be of help. I on...Hi Juan,<br /><br />Unfortunately, I cannot be of help. I only have a printed version of the paper, and presently no journal access, so cannot download a PDF. Maybe somebody else can send one? Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-81009851899054848242012-01-26T07:34:01.411-05:002012-01-26T07:34:01.411-05:00Where could I get a free copy of the paper? I am v...Where could I get a free copy of the paper? I am very interested into study it!<br />Best wishes!Jhttps://www.blogger.com/profile/01942050607289418780noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-75218815338730138652012-01-26T04:48:56.195-05:002012-01-26T04:48:56.195-05:00Thanks Bee for taking the time to answer these que...Thanks Bee for taking the time to answer these questions.Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-6205258686090562062012-01-26T04:29:52.206-05:002012-01-26T04:29:52.206-05:00The photon's energy always exceeds the Planck ...The photon's energy always exceeds the Planck energy in some restframe. But yes, if that is what you mean, if it interacts with the particle at very high energies, a microscope isn't anymore a very good analogy since, as you say, you'd have a very inelastic scattering and you'd have to figure out what was going on from the outgoing particles rather than watching photons on a Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-78287966636419169712012-01-26T04:25:48.831-05:002012-01-26T04:25:48.831-05:00The Compton wavelength as a limit for which positi...The Compton wavelength as a limit for which positions measurements become ill defined due to creation of particles. I mean if the energy of the photon exceeds some limit according to QFT particles would be created.Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-10574656691697314292012-01-26T04:20:01.396-05:002012-01-26T04:20:01.396-05:00I am probably misunderstanding the question. The C...I am probably misunderstanding the question. The Compton wavelength of what?Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-41704629363844827732012-01-26T04:16:38.783-05:002012-01-26T04:16:38.783-05:00and what is the relation with the Compton waveleng...and what is the relation with the Compton wavelength?Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-55798060747896182712012-01-26T04:13:50.001-05:002012-01-26T04:13:50.001-05:00Hi Aaron,
Yes, without spherical symmetry one may...Hi Aaron,<br /><br />Yes, without spherical symmetry one may expect that volumes are the relevant quantity to talk about. <a href="http://arxiv.org/abs/hep-th/0303037" rel="nofollow">This argument has been made eg here (page 5/6)</a>, and though plausible it is not particularly bloggable if you see what I mean. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-23501201122981885832012-01-26T04:03:49.432-05:002012-01-26T04:03:49.432-05:00Hi Giotis,
No, he does it fully relativistic also...Hi Giotis,<br /><br />No, he does it fully relativistic also, I just haven't added the more complete argument here. If you turn up the energy of the photon you can get down the wavelength. If you don't take into account gravity, you can do this arbitrarily. The point is here that when you reach Planckian energies, you start perturbing the particle you are trying to measure in such a way Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-35397694600867095422012-01-26T04:00:15.730-05:002012-01-26T04:00:15.730-05:00Hi Bee,
The Compton wavelength limit normally wou...Hi Bee,<br /><br />The Compton wavelength limit normally would have a priority. But I guess he considers non relativistic physics only.Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-1055389056258235362012-01-26T01:42:09.756-05:002012-01-26T01:42:09.756-05:00Hi Plato,
It's not so much my choice of font ...Hi Plato,<br /><br />It's not so much my choice of font as the default that came with the template. You are right, the italics are difficult to see. I'll try to change the font, I'm not a big fan of arial anyway. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-73929665950407735652012-01-25T18:30:50.518-05:002012-01-25T18:30:50.518-05:00Hi Bee,
The derivation of the Heisenberg principl...Hi Bee,<br /><br />The derivation of the Heisenberg principle, interestingly enough, does not involve the electric charge, i.e., how the photon couples to the particle is not relevant.<br /><br />For the gravity case, G enters, however, we are only after Δx. I suppose a careful argument using EM analogous to the Mead argument would yield<br /><br />Δ x ≥ fine structure constant * compton Arunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-54952151632814346072012-01-25T16:26:13.085-05:002012-01-25T16:26:13.085-05:00Shouldn't that be generalized to a Planck volu...Shouldn't that be generalized to a Planck volume instead?<br /><br />Which you could combine the the Heisenberg uncertainty principle to ensure that singularities are not observable? <br /><br />Namely:<br />$ <br />\Delta volume \times \Delta mass \geq <br />\frac{\hbar \times length_planck}{c}<br />$Anonymousnoreply@blogger.com