tag:blogger.com,1999:blog-22973357.post2944862699733039286..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: Live Seminar about Dark Matter on FridaySabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger28125tag:blogger.com,1999:blog-22973357.post-90145566377437400862021-04-10T14:39:34.136-04:002021-04-10T14:39:34.136-04:00Any news about when this will be available. I was...Any news about when this will be available. I was only half way through when it disappeared.oporterhttps://www.blogger.com/profile/14511309433874160860noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-83271773984737753392021-04-01T01:14:54.579-04:002021-04-01T01:14:54.579-04:00Good morning Sabine,
it seems to me that such a b...Good morning Sabine,<br /><br />it seems to me that such a blog is really very hard work.<br />I think it's admirable to post something interesting every week - for over 10 years. <br />I could do it too, but only for 3 weeks. And then there are the comments. It would give me a headache too. (Without Seven Evans your blog would become very dreamy....)<br /><br />I asked AstrofisicaUC about Stefan Freundthttps://www.blogger.com/profile/04834262116439292657noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-78023426271313567352021-03-29T20:02:47.710-04:002021-03-29T20:02:47.710-04:00Just checked the Golden Webinars link that Sabine ...Just checked the Golden Webinars link that Sabine posted, where a recording of her seminar on Dark Matter will be presented. It's not yet up at that site, but to my delight my favorite astrophysicist, Stacy McGaugh, posted a seminar titled "Dark Matter and Gravity", which I'm currently watching.David Schroederhttps://www.blogger.com/profile/18048116250413347228noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-3378541646286985612021-03-26T07:03:18.371-04:002021-03-26T07:03:18.371-04:00The difference is that gravitational attraction of...The difference is that gravitational attraction of masses puts the two masses on inertial frames. An electrostatic attraction puts them on accelerated frames. Lawrence Crowellhttps://www.blogger.com/profile/12090839464038445335noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-15288827226489885192021-03-25T13:32:58.509-04:002021-03-25T13:32:58.509-04:00I have not seen the seminar (hoping the video will...I have not seen the seminar (hoping the video will be available soon), thus just guessing here.<br /><br />Two oppositely electrically charged bodies will exert gravity-like (attractive, 1/r^2) force on each other, while they will not interact this way with electrically non-charged bodies. And this does not violate the equivalence principle.<br /><br />Still, since different bodies see M. Artinshttps://www.blogger.com/profile/16671160715854896336noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-25415955517413086202021-03-24T09:42:57.025-04:002021-03-24T09:42:57.025-04:00No, not on my channel, but on this channel
https:...No, not on my channel, but on this channel<br /><br />https://www.youtube.com/channel/UCyCyGFLfUZhaly2WsXJIXAQ<br /><br />As you see, it hasn't yet appeared. I'll post the link here if it goes online. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-89079245770347103102021-03-24T09:31:40.065-04:002021-03-24T09:31:40.065-04:00Any link for this yet? Will it be on your youtube...Any link for this yet? Will it be on your youtube channel? George Heroldhttps://www.blogger.com/profile/10856527872293160233noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-19044459709290773832021-03-23T06:16:58.225-04:002021-03-23T06:16:58.225-04:00This still causes consternation to me. It is maybe...This still causes consternation to me. It is maybe the case, but something that "looks like gravity" is if sufficiently similar is, well ... gravity. This is by that great logic of if it looks like a duck, swims like a duck, quacks like a duck then it is a duck. <br /><br />I have had this idea kicking around, which fits into this multiverse idea, that pocket worlds may have their Lawrence Crowellhttps://www.blogger.com/profile/12090839464038445335noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-67126650574140230712021-03-22T13:22:52.384-04:002021-03-22T13:22:52.384-04:00Lawrence,
I am afraid you are misunderstanding ho...Lawrence,<br /><br />I am afraid you are misunderstanding how superfluid dark matter works. It's a condensate which mediates an additional force that looks like gravity in that it couples to the stress-energy. However, there is nothing in this formalism that says the force needs to couple to all particles. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-12772830595143624872021-03-22T10:21:13.877-04:002021-03-22T10:21:13.877-04:00If this is all gravity, even MOND gravity, this se...If this is all gravity, even MOND gravity, this seems to imply gravity couples differently with photons than with matter. That appears to have issues with one of the statements of the equivalence principle that gravitation acts on mass-energy independent of it's structure. At least this is a caveat that co.ea tomi d if interpret your statement here correctly.<br /><br />Suppose I had one box Lawrence Crowellhttps://www.blogger.com/profile/12090839464038445335noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-82839052949211226422021-03-22T02:50:34.656-04:002021-03-22T02:50:34.656-04:00Of course not. Neutrinos don't couple to photo...Of course not. Neutrinos don't couple to photons, but that doesn't violate the equivalence principle. I don't know what you're even talking about. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-83752539828768245312021-03-22T02:04:56.193-04:002021-03-22T02:04:56.193-04:00It goes against the equivalence principle.It goes against the equivalence principle.Lawrence Crowellhttps://www.blogger.com/profile/12090839464038445335noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-88980899652108294082021-03-20T04:19:01.256-04:002021-03-20T04:19:01.256-04:00It was a live stream. It automatically goes offlin...It was a live stream. It automatically goes offline once finished. It will take a few days for the recording to be uploaded. I'll post a link then. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-70943330196801565962021-03-20T04:17:34.833-04:002021-03-20T04:17:34.833-04:00Was looking forward to watching this live but coul...Was looking forward to watching this live but couldn't find it. Now this video is marked "private."Robert Hunthttps://www.blogger.com/profile/13089978161317813973noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-66862053021896057412021-03-20T02:53:11.429-04:002021-03-20T02:53:11.429-04:00Yes, will be uploaded later. Yes, will be uploaded later. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-26214295466001310462021-03-20T02:52:51.895-04:002021-03-20T02:52:51.895-04:00Too ugly, huh? Can we please get over this? Some p...Too ugly, huh? Can we please get over this? Some particles couple to other particles, others don't. There's no problem with this whatsoever. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-86093436225338514772021-03-19T22:00:47.682-04:002021-03-19T22:00:47.682-04:00Due to a scheduling conflict I only caught snippet...Due to a scheduling conflict I only caught snippets of this towards the very end, but I very much liked what I saw. Sabine, this was a great topic and I think you did a great job of explaining both why it's interesting and how it may get even more so in the near future. Thanks!Terry Bollingerhttps://www.blogger.com/profile/03915136249111338024noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-86480504928119946882021-03-19T17:33:47.348-04:002021-03-19T17:33:47.348-04:00Will it be uploaded to YT later? I couldn't fo...Will it be uploaded to YT later? I couldn't follow it live. siwyhttps://www.blogger.com/profile/14647856211603818156noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-901736844212357102021-03-19T14:29:58.790-04:002021-03-19T14:29:58.790-04:00Thank you very much. I enjoyed your presentation ...Thank you very much. I enjoyed your presentation which was very well organized. I was glad to hear that you are continuing to pursue this research, some. I thought you were very diplomatic during the Q&A when questioners brought up some very speculative ideas.<br /><br />To answer Jim Birch's question, it was announced that an HD version would be put out on the organization's web SteveBhttps://www.blogger.com/profile/17941994830402297327noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-36047295872534899482021-03-19T14:13:24.649-04:002021-03-19T14:13:24.649-04:00A very intersting presentation giving a good impre...A very intersting presentation giving a good impression of the idea perhaps widening the research on what Dark Matter could be.<br />You mentioned the open question of which effects could correspond to the phase transition and how it might show up in obsservations. This reminded me of the split of measuremnts of the Hubble Constant (local/recent versus cosmological/early) in this context? Could M_Malenfanthttps://www.blogger.com/profile/09809944942172355661noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-48486342147235644452021-03-19T14:11:34.257-04:002021-03-19T14:11:34.257-04:00I remember reading your paper on covariant form of...I remember reading your paper on covariant form of Verlinde's work. It maybe don't remember it, but somehow the idea there is are different interactions for baryonic matter and photons does not strike me well. Lawrence Crowellhttps://www.blogger.com/profile/12090839464038445335noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-27982511039812295332021-03-19T14:01:47.399-04:002021-03-19T14:01:47.399-04:00Happy you liked it!Happy you liked it!Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-88937949093182755682021-03-19T14:01:30.916-04:002021-03-19T14:01:30.916-04:00Personally, I would agree with you. But it seems t...Personally, I would agree with you. But it seems to me that different communication channels work for different people and I think it's good to use all of them to reach as many people as possible. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-79864308227006503452021-03-19T13:18:57.367-04:002021-03-19T13:18:57.367-04:00I generally would much rather read something than ...I generally would much rather read something than listen to it--but that was well worth the time I spent watching it. I thought it was well done, which must have required preparation and experience. It does add a bit of color/drama/je-ne-sais-quoi to see and hear a live presentation (when it goes well). A few of the questioners' comments were difficult for me to follow due to their accents, JimVhttps://www.blogger.com/profile/10198704789965278981noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-73063984712682970022021-03-19T13:05:25.592-04:002021-03-19T13:05:25.592-04:00very nice presentation
Stefanvery nice presentation<br />StefanStefan Freundthttps://www.blogger.com/profile/04834262116439292657noreply@blogger.com