tag:blogger.com,1999:blog-22973357.post3982581072176790306..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: MAGIC's observation of Gamma Ray burstsSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger37125tag:blogger.com,1999:blog-22973357.post-78277456186363431172008-12-17T14:46:00.000-05:002008-12-17T14:46:00.000-05:00This comment has been removed by the author.PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-17954726190567410222007-10-03T17:46:00.000-04:002007-10-03T17:46:00.000-04:00Hi Alessandro:Thanks for your comment. However, yo...Hi Alessandro:<BR/><BR/>Thanks for your comment. However, your remarks 'it is said in the blog' and 'the author of the blog did not probably know' does not refer to my blog and this post. Best,<BR/><BR/>B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-39579230367483574122007-10-03T17:15:00.000-04:002007-10-03T17:15:00.000-04:00Let us start from the experimental facts. The MAGI...Let us start from the experimental facts. The MAGIC collaboration has detected a short flare (about 2 minutes) from the galaxy Mkn 501; this flare has been seen from energies of about 100 GeV to energies 100 times higher. The data show a time delay of about 4 minutes between the lowest and the highest energy gamma rays; this delay is significant beyond the 95% C.L..<BR/><BR/>Now the alessandro de angelishttps://www.blogger.com/profile/16854621837492704887noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-1625990168789813122007-08-29T17:35:00.000-04:002007-08-29T17:35:00.000-04:00Anonymous and Bee,Thanks!Here's a description of t...Anonymous and Bee,<BR/><BR/>Thanks!<BR/><BR/>Here's a description of the parsec-scale jet producing these Tev gamma-rays:<BR/><BR/>http://arxiv.org/abs/astro-ph/0210482<BR/><BR/>Maybe it's possible to imagine some time and wavelength-dependent effects originating there.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-5834566130249096242007-08-29T13:33:00.000-04:002007-08-29T13:33:00.000-04:00This is what 30 years of String has done to physic...This is what 30 years of String has done to physics. Wild speculations sold as facts form the foundation of career advancement. The authors would be fools not to play the game, so I find Bee's astonishment astonishing.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-32622796702475495902007-08-29T11:21:00.000-04:002007-08-29T11:21:00.000-04:00Hi Kris,Anonymous above is right that interstellar...Hi Kris,<BR/><BR/>Anonymous above is right that interstellar medium wouldn't affect the travel time, but the intensity (Though the frequency dependence depends on the kind of scattering. <A HREF="http://motls.blogspot.com/2007/08/magic-dispersion-of-gamma-rays.html" REL="nofollow">Lubos had something to say about that</A>.) Also, the medium would have to be very thin, otherwise it would have a Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-85205480752038585632007-08-29T09:54:00.000-04:002007-08-29T09:54:00.000-04:00If the observed delay were due to a effect such as...If the observed delay were due to a effect such as scattering as the gammmas propagate through interstellar space, I think this would only effect the intensity of the gammas rays and not affect the time of arrival. Furthermore, one would expect the shorter wavelength photons to be affected less since they have a small scattering cross-section.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-55669588432872667862007-08-29T02:34:00.000-04:002007-08-29T02:34:00.000-04:00Great post Bee!Can anyone bring me up to speed on ...Great post Bee!<BR/><BR/>Can anyone bring me up to speed on the ordinary optical properties of the interstellar and intergalactic media at these wavelengths? Are they well-established?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-30556030442654587102007-08-28T18:48:00.000-04:002007-08-28T18:48:00.000-04:00Thanks for the analysis, Bee!Thanks for the analysis, Bee!eric gissehttps://www.blogger.com/profile/10598878490537720448noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-27599335038103343302007-08-28T13:23:00.000-04:002007-08-28T13:23:00.000-04:00you have already been very kind and patient in you...you have already been very kind and patient in your response, thanks!<BR/><BR/>I shall understand if you don't have time for further dialog, but I shall pursue this using the Martin Reuter case<BR/><BR/>**as far as I know neither sign is a problem to come up with theoretically.**<BR/><BR/>Reuter model has G_k and Lambda_k that run with inverse scale k, leading to a metric g_k<BR/><BR/>the Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-82876210709350909282007-08-28T10:37:00.000-04:002007-08-28T10:37:00.000-04:00PS: You say "They showed they had sufficient sensi...PS: You say <I>"They showed they had sufficient sensitivity to detect positive correlation (energy with speed) and they report they did not find positive correlation."</I> Again, let me point out the problem here is not to have sufficient sensitivity to measure a delay but to find out whether this delay originated during the propagation from the source to us.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-65550681805788782832007-08-28T10:17:00.000-04:002007-08-28T10:17:00.000-04:00Hi Who:The result is a 2.5 sigma signal, I will th...Hi Who:<BR/><BR/>The result is a 2.5 sigma signal, I will think about it should it be confirmed. I don't like to assign probabilities, as they hardly reflect my opinion - I hope the post did a better job there, but since you asked. Probability for the signal to be confirmed with other signals (other sources): 5%. Probability that in case it was confirmed it is a quantum gravitational effect: 10 %Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-25704067828595563642007-08-28T10:15:00.000-04:002007-08-28T10:15:00.000-04:00George Musser(Sciam) follows the conversations qui...George Musser(Sciam) follows the conversations quite a lot. You can see him at cosmic variance and such, stimulated by such conversations. <BR/><BR/>Nurturing the public media reach with regards to science, a scientist would know to correct?<BR/><BR/>I mean we can all learn by the responses given, and of course by our reading from the learned individuals, who present us information on this or anyAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-33510188103822926612007-08-28T09:58:00.000-04:002007-08-28T09:58:00.000-04:00*Yes. I am not saying the result is completely uni...*Yes. I am not saying the result is completely uninteresting, and there is of course a non-vanishing probability that it will be confirmed.*<BR/><BR/>Thanks for the friendly and reasonable reply, Bee. People's tempers seem frayed by this and they seem more worked up than usual.<BR/><BR/>What would you say the result is, and what would you estimate the probability it will be confirmed?<BR/><BR/>Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-29370714267937676652007-08-28T03:38:00.000-04:002007-08-28T03:38:00.000-04:00lol Bee, 'fast' & 'catchy' headlinesI like your an...lol Bee, 'fast' & 'catchy' headlines<BR/>I like your analogy of a packet of photons being like a family pushing its way thru a crowd. The individual members of the family are 'quanta' <BR/><BR/>and higher energy phonoss more affected by QG than lower energy?QUASAR9https://www.blogger.com/profile/00593390598251093182noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-28309910132801894962007-08-27T21:09:00.000-04:002007-08-27T21:09:00.000-04:00Hi Who:Yes. I am not saying the result is complete...Hi Who:<BR/><BR/>Yes. I am not saying the result is completely uninteresting, and there is of course a non-vanishing probability that it will be confirmed. However, for a flare with a delay of the order of minutes I'd think the challenge is not so much detecting the delay, but to cope with the lack of knowledge about the original signal - i.e. confirming that it is indeed a delay, and not a Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-6420197799193424652007-08-27T17:24:00.000-04:002007-08-27T17:24:00.000-04:00but the only thing you get from hyping non-results...but the only thing you get from hyping non-results is more people wasting time with alleged 'effects' and made-up 'predictions'. Yes, I do think scientific publications should be conservative and cautious, especially if they claim to have evidence for new physics. <BR/><BR/><B>Bee, I think they (and Sciam) admit to wanting to stimulate debate</B><BR/><BR/>Reading papers and follow-up articles QUASAR9https://www.blogger.com/profile/00593390598251093182noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-84645084788606967942007-08-27T12:57:00.000-04:002007-08-27T12:57:00.000-04:00Chirping a waveform is not overturning the foundat...<I>Chirping a waveform is not overturning the foundations of physics</I><BR/><BR/>If seen in "another light":)as the joining of "gravity and electromagnetism" maybe?<BR/><BR/>One does not discount the "geometrical implication" of the absence of? <BR/><BR/>QGP may be one extend, while the other end is? "Strange qualities" of the viscosity allow for an state of inertia for "relativistic flows?"Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-44082421854857786992007-08-27T12:39:00.000-04:002007-08-27T12:39:00.000-04:00Postulating vacuum dichroism based upon a received...Postulating vacuum dichroism based upon a received signal envelope from an unknown orginal shape is madness. This class of ambiguation is used to rationalize superluminal signal propagation. Chirping a waveform is not overturning the foundations of physics.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-21333694813046189742007-08-27T12:19:00.000-04:002007-08-27T12:19:00.000-04:00**Reading papers and follow-up articles with exagg...**Reading papers and follow-up articles with exaggerated claims about testing quantum gravity annoys me considerably. It's like strawberry yogurt where the fineprint says 'no fruit'.**<BR/><BR/>there's fruit. It just might not be strawberries. <BR/>The IACT is a new kind of telescope. Imaging air cherenkov telescope. Theirs is a 17 meter optical dish.<BR/>They can detect the arrival of a single Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-42764259582998826072007-08-27T12:09:00.000-04:002007-08-27T12:09:00.000-04:00Hi Lubos,I don't want to sink any ship. I just wan...Hi Lubos,<BR/><BR/>I don't want to sink any ship. I just want a balanced analysis and presentation of facts and potential explanations. Yes of course theorists should offer explanations, but then they should also take into account all other constraints that there are on a used setup, and give sufficient space to other explanations. Claiming that this signal is an indication for quantum gravity Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-84240270958675487492007-08-27T11:53:00.000-04:002007-08-27T11:53:00.000-04:00Dear Sabine, expectations are built-in in papers b...Dear Sabine, expectations are built-in in papers but one must still distinguish what is an expectation and what is a fact. The real point I don't understand is why you write papers on mutated Lorentz invariances and similar stuff if you're actually so skeptical - much like I am - that these effects exist.<BR/><BR/>When we say that the origin will be delayed because of astrophysical reasons, we Luboš Motlhttps://www.blogger.com/profile/17487263983247488359noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-44626260115638635062007-08-27T11:30:00.000-04:002007-08-27T11:30:00.000-04:00If the earth's gravitational self-energy does not ...<A HREF="http://physics.ucsd.edu/~tmurphy/apollo/apollo.html" REL="nofollow">If the earth's gravitational self-energy does not precisely obey the Equivalence Principle, the orbits of the earth and moon around the sun would be slightly displaced from one another (think of this as a modification of Kepler's third law), which would show up as a signal in our lunar range data. <B>Various Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8672009344828174322007-08-27T11:07:00.000-04:002007-08-27T11:07:00.000-04:00If one was to assume that such a place existed tha...If one was to assume that such a place existed that satellites could have found "stationary orbits" then why not the position indicated in the sun earth relation L1 or L2. Routes in space?<BR/><BR/>In space such a equilibrium could be struck? Could be the "<A HREF="http://www.cerncourier.com/objects/2004/CCEsym2_12-04.jpg" REL="nofollow">tipping point</A>."<BR/><BR/>Layman thinking.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-64394946714465557122007-08-27T10:41:00.000-04:002007-08-27T10:41:00.000-04:00Yes of course the source was not given,Bee:assumin...Yes of course the source was not given,<BR/><BR/><BR/><B>Bee</B>:<I>assuming a parameter dependent blurring has taken place that distorts the signal differently in different energy regimes. If one reconstructs the original signal with that assumption, one can examine it for certain features, and ask for the parameter that optimizes that feature. </I><BR/><BR/>Lensing would have had to be Anonymousnoreply@blogger.com