tag:blogger.com,1999:blog-22973357.post1166005863186353392..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: Experimental Search for Quantum Gravity 2016Sabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger39125tag:blogger.com,1999:blog-22973357.post-15369126579824490392016-09-27T03:18:02.477-04:002016-09-27T03:18:02.477-04:00akidbelle/J,
I have an answer to your above quest...akidbelle/J,<br /><br /><a href="http://backreaction.blogspot.com/2016/09/dear-dr-b-what-do-physicists-mean-by.html" rel="nofollow">I have an answer to your above question what we mean by "quantum gravity" (very top of thread) here.</a>Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-74387221981559444292016-09-26T12:57:20.059-04:002016-09-26T12:57:20.059-04:00Shantanu,
Not yet. Shouldn't be that much lon...Shantanu,<br /><br />Not yet. Shouldn't be that much longer. I'm about to upload the slides.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-29102368265437680532016-09-26T12:45:33.202-04:002016-09-26T12:45:33.202-04:00Are the recordings of the talks online? I couldn&...Are the recordings of the talks online? I couldn't find the links<br />shantanu Shantanuhttps://www.blogger.com/profile/16322812456382858228noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-33360259800713182512016-09-25T17:20:39.511-04:002016-09-25T17:20:39.511-04:00http://arxiv.org/abs/1609.01421 "in every maj...http://arxiv.org/abs/1609.01421 "<i>in every major theory of physics, challenging mathematical questions arise from the assumption that spacetime is a continuum</i>" Discrete lattice achiral symmetry (e.g., quantum spacetime) fails<b>[1]</b>. Periodic lattices plus quantum spacetime attack vacuum isotropy<b>[2]</b>.<br /><br />Periodic crystals’ unit cells self-similarly tessellate Uncle Alhttps://www.blogger.com/profile/05056804084187606211noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-57624579401143076462016-09-21T05:59:33.485-04:002016-09-21T05:59:33.485-04:00Indeed they are, my bad. "D" is dayligh...Indeed they are, my bad. "D" is daylight, "S" is summer. I was thinking "S" was "standard". Without daylight-saving time, it's just CET. In any case, UTC + two hours.<br />Phillip Helbighttps://www.blogger.com/profile/12067585245603436809noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-16074819153438690312016-09-21T05:52:35.608-04:002016-09-21T05:52:35.608-04:00Phillip,
For all I can tell they're presently...Phillip,<br /><br />For all I can tell they're presently the same. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-87760054761698318452016-09-21T02:51:17.935-04:002016-09-21T02:51:17.935-04:00The times appear to be CEDT, not CEST.
The times appear to be CEDT, not CEST.<br />Phillip Helbighttps://www.blogger.com/profile/12067585245603436809noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-53471327427564717432016-09-20T07:14:14.267-04:002016-09-20T07:14:14.267-04:00Helder,
The broadcast for the first talk was stop...Helder,<br /><br />The broadcast for the first talk was stopped because the speaker hadn't signed the consent form. Sorry about this. The other speakers today have all signed it, so there should be no more interruptions. I will ask about the brightness. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-59672589692827337722016-09-20T05:07:59.438-04:002016-09-20T05:07:59.438-04:00Not CEDT? It lasts until the last Sunday in Octob...Not CE<b>D</b>T? It lasts until the last Sunday in October.<br /><br />Phillip Helbighttps://www.blogger.com/profile/12067585245603436809noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-88591033339769719672016-09-20T04:22:27.409-04:002016-09-20T04:22:27.409-04:00Dear Dr. Hossenfelder,
My name is Helder Lar...Dear Dr. Hossenfelder,<br /><br /> My name is Helder Larraguivel. I started to see the live stream video of one of the lectures, when all the sudden the broadcasting stopped.<br /><br /> Also, the white bright background of the screen and presentation makes it impossible to see anything in the slides. Just so that you could take it into account.<br /><br />Thank you very much for your Helder Larraguivelhttps://www.blogger.com/profile/16336207712819530579noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-34031602259534819442016-09-20T01:14:32.088-04:002016-09-20T01:14:32.088-04:00Don,
Yes, the times are CEST. Don,<br /><br />Yes, the times are CEST. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-80280818407672096962016-09-19T22:57:00.281-04:002016-09-19T22:57:00.281-04:00The times given in the streaming schedule are Fran...The times given in the streaming schedule are Frankfurt time, right?Don Fosterhttps://www.blogger.com/profile/04814669413022486958noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-87125887314991046682016-09-18T17:54:58.194-04:002016-09-18T17:54:58.194-04:00Happy birthday Bee!Happy birthday Bee!David Schroederhttps://www.blogger.com/profile/18048116250413347228noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-26208892712053517622016-09-18T15:30:46.644-04:002016-09-18T15:30:46.644-04:00Cool, thanks Sabine. Can't wait to see these.Cool, thanks Sabine. Can't wait to see these.Statichttps://www.blogger.com/profile/12047878044158328143noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-25058074882034936492016-09-18T11:10:12.442-04:002016-09-18T11:10:12.442-04:00What requires a black hole to have internal volume...What requires a black hole to have internal volume and a singularity? Neither are described by physics. Both are inconsistent with LIGO event GW150914. Black holes (BHs) massing 30 or a billion sols may contain mass within externally-viewed volume or a (2 + L_P)-dimensional event horizon shell (L_P = Planck length)). Mass distribution moments of inertia are the "same" for both cases,Uncle Alhttps://www.blogger.com/profile/05056804084187606211noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-28517892406444627532016-09-18T05:29:44.349-04:002016-09-18T05:29:44.349-04:00Static,
Yes. But I don't know exactly when or...Static,<br /><br />Yes. But I don't know exactly when or where. I'll let you know here once it's online.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-50188621531026233692016-09-18T03:22:35.900-04:002016-09-18T03:22:35.900-04:00This whole conference is happening during my sleep...This whole conference is happening during my sleep schedule, will recordings be available anywhere?Statichttps://www.blogger.com/profile/12047878044158328143noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-24444830572628539442016-09-18T01:46:46.717-04:002016-09-18T01:46:46.717-04:00Tom,
Well, no, most in the community think it doe...Tom,<br /><br />Well, no, most in the community think it does not couple to the expectation value, that's just an approximation. Yeah, you can think of other options, been there done that. Try to write down a consistent theory, publish it, and we can talk. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-70743565517139287052016-09-17T14:02:49.297-04:002016-09-17T14:02:49.297-04:00Thanks - I had not looked at the Schrödinger-Newto...Thanks - I had not looked at the Schrödinger-Newton equation much before. I am reading the "Is Quantum Gravity Necessary" paper by Carlip now. http://arxiv.org/abs/0803.3456. <br /><br />One difference between those papers and what I was talking about is that there seems to be a general agreement that the gravitational field couples to the 'expectation value' . There is also Tom Andersenhttps://www.blogger.com/profile/17562906116020498110noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-23819794048245470182016-09-17T11:41:00.909-04:002016-09-17T11:41:00.909-04:00Tom,
This might also answer your question.Tom,<br /><br /><a href="http://backreaction.blogspot.de/2012/04/schrodinger-meets-newton.html" rel="nofollow">This might also answer your question.</a>Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-57456739163361484172016-09-17T11:39:55.913-04:002016-09-17T11:39:55.913-04:00Tom,
I think you might be interested in Andre Gro...Tom,<br /><br />I think you might be interested in Andre Grosshardt's talk (on Friday), which will address the question you ask.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-63850890084682987832016-09-17T10:37:09.243-04:002016-09-17T10:37:09.243-04:00Sabine,
I will be watching some of the lectures o...Sabine,<br /><br />I will be watching some of the lectures on video. Thanks for the reminder.<br /><br />I fully realize that to most physicists, E = hv is just as true in gravity as it is in electromagnetism, but there exists no experiment to show that this relation also holds for gravity. What if gravity is not quantized at all? Are there any experiments that could detect that? <br /><br />Tom Andersenhttps://www.blogger.com/profile/17562906116020498110noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-91533394010821502922016-09-17T02:44:46.844-04:002016-09-17T02:44:46.844-04:00Captain,
I'm not sure why you ask whether I a...Captain,<br /><br />I'm not sure why you ask whether I agree with what I just wrote in my post. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-19835870374128534482016-09-17T02:28:10.217-04:002016-09-17T02:28:10.217-04:00Hi Bee,
Would you agree that progress in this are...Hi Bee,<br /><br />Would you agree that progress in this area has been slow because the various quantum gravity approaches being researched make no new predictions that can be verified by experiment today? Doesn't matter how much beauty a model has, if nature doesn't agree with it then it is not much use. Shouldn't all models proposed have an obligation to ask nature if their model isPaul Titzehttps://www.blogger.com/profile/18289833231312747076noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-46446992224706003562016-09-17T02:25:55.298-04:002016-09-17T02:25:55.298-04:00Nathan,
First, if you like differential geometry,...Nathan,<br /><br />First, if you like differential geometry, you could do the easy thing and go into GR (classical), which is presently blooming especially in the gravitational wave regime (guess why). Yes, much of it is numerical, but it's close enough to what you seem to be interested in. And what most of us do anyway is that we have what my supervisor used to call 'butter-and-bread'Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.com