tag:blogger.com,1999:blog-22973357.post4495885236575137588..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: Dear Dr. B: What is emergent gravity?Sabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger26125tag:blogger.com,1999:blog-22973357.post-55900133693759266982016-12-06T00:48:42.714-05:002016-12-06T00:48:42.714-05:00Even,
Well, I'll have to tell you once again ...Even,<br /><br />Well, I'll have to tell you once again that you don't seem to understand what I'm saying. I did not, not here and not anywhere else, say that 'a reductionist explanation of consciousness [is] the only explanation'. And no, reductionism is not philosophy. It's a hypothesis that is confirmed by countless experiments. Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-87748825142710623742016-12-05T16:38:24.648-05:002016-12-05T16:38:24.648-05:00Sabine,
You keep saying I don't understand you...Sabine,<br />You keep saying I don't understand you. Did it ever occur to you that I do understand what you're saying, but I just have a different point of view? For example, I do not agree that reductionism IS science. Reductionism is philosophy. Science is a method. Particularly, a method that should be kept as free as possible from philosophy and any other predisposed way of viewingAnonymoushttps://www.blogger.com/profile/02260017465845457855noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-65178069815249722592016-12-05T03:48:16.818-05:002016-12-05T03:48:16.818-05:00The discussions about strong emergence do remind m...The discussions about strong emergence do remind me of the discussions on determinism of time. Is the future completely predetermined by the state of the universe now? Yes, if we ascribe to causality.<br /><br />After the fact, we can always find the causes of any event. However, we are stubbornly unable to predict the future. And there are arguments that, in a worst case scenario, we cannot Rob van Son (Not a physicist, just an amateur)https://www.blogger.com/profile/12611755507524401026noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-44885479612011117872016-12-04T02:29:49.561-05:002016-12-04T02:29:49.561-05:00Douglas,
It is possible to have strong emergence ...Douglas,<br /><br />It is possible to have strong emergence but that requires (to make a long story short) a breakdown of effective field theory. And a breakdown not just in a way of "is no longer practical" or "can't be calculated" but in a way of "doesn't follow" and "stops here at this point". There isn't any example of that. <br /><br />I Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-7699594873619184342016-12-03T20:30:30.022-05:002016-12-03T20:30:30.022-05:00Sabine, great blog post as always. As a condensed...Sabine, great blog post as always. As a condensed matter person who just finished teaching undergrad stat mech for the semester, emergence is a favorite topic, and I was thinking about writing a post of my own about emergent gravity, but now that might be superfluous.<br /><br />One question. Isn't your take on strong emergence approaching the "no true Scotsman" argument? I mean,Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-55425728848960721492016-12-03T14:00:43.669-05:002016-12-03T14:00:43.669-05:00I tend to be skeptical of emergent gravity ideas. ...I tend to be skeptical of emergent gravity ideas. There have been several developments in quantum gravity research in the last few decades that indicate that general relativity and quantum mechanics are not as incompatible as once was believed.<br />Loop quantum gravity, asymptotic safety, causal dynamical triangulations: they all hint that a quantized version of GR is well-behaved in the Anonymoushttps://www.blogger.com/profile/07133184819402137578noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8855190887708864112016-12-03T01:35:29.203-05:002016-12-03T01:35:29.203-05:00Evan,
You are plainly wrong to think that it'...Evan,<br /><br />You are plainly wrong to think that it's based on no evidence and I find it remarkable how you simply ignore what I am telling you. I am telling you that to our best current knowledge of the laws of nature the behavior of large objects follows from that of its constituents. There isn't any known way to avoid that. There isn't any known exception. You are clinging ontoSabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-88992921825537016522016-12-02T19:41:10.125-05:002016-12-02T19:41:10.125-05:00Thank you Sabine for your clear explanation. I jus...Thank you Sabine for your clear explanation. I just took a course and learned a little about the work of Erik Verlinde. Promising!Anonymoushttps://www.blogger.com/profile/05141430270554010270noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-7707003460280220352016-12-02T16:51:25.649-05:002016-12-02T16:51:25.649-05:00Sabine,
If you re-read my comment, I made no clai...Sabine,<br /><br />If you re-read my comment, I made no claims. I was just pointing out your claim that free will is "emergent" is a non-evidence based claim. Not only that, it is good to realize the claim is based on a materialistic/reductionist world view, or paradigm. As we all know, all worldviews/philosophies/paradigms ultimately prove themselves limited, so it can be dangerous Anonymoushttps://www.blogger.com/profile/02260017465845457855noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-10650967758325134182016-12-02T00:59:36.886-05:002016-12-02T00:59:36.886-05:00Mars,
That's a good question. I'll bookma...Mars,<br /><br />That's a good question. I'll bookmark this for a future "Dear Dr B." Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-81750430948599384912016-12-02T00:55:15.204-05:002016-12-02T00:55:15.204-05:00Gabe,
That space-time is emergent means you use t...Gabe,<br /><br />That space-time is emergent means you use the qbits to define what "where" and "when" means. Ie, your question makes no sense.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-82166224522432010572016-12-01T12:00:24.714-05:002016-12-01T12:00:24.714-05:00Emergent gravity makes sense to me; emergent space...Emergent gravity makes sense to me; emergent spacetime does not. Can you explain WHERE and WHEN the qubits from which spacetime emerges exist? Are their interactions “happening” in a Platonic heaven?Gabehttps://www.blogger.com/profile/16013606619560424072noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-27827580016486836142016-12-01T11:54:01.091-05:002016-12-01T11:54:01.091-05:00Sabine, I have had a basic question for a long tim...Sabine, I have had a basic question for a long time. What is AdS space? where does it exist in our world?<br />I understand we live in a de-sitter space. Does Anti-de-sitter space exist inside a black hole?<br /><br />Thanks.Marshttps://www.blogger.com/profile/04239781610286869336noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-59988145825016365612016-12-01T11:16:16.294-05:002016-12-01T11:16:16.294-05:00Evan,
Another one who is being annoyed? Well, it ...Evan,<br /><br />Another one who is being annoyed? Well, it seems then I have to repeat it once again. The laws of nature that we have found imply that the equations that determine the behavior of large things follow from the underlying laws. There is no known way to AVOID this. There isn't any known exception to this. If you claim that strong emergence exists, then you are the one making an Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-77334827160571954062016-12-01T10:56:17.980-05:002016-12-01T10:56:17.980-05:00" to our current best knowledge this includes..." to our current best knowledge this includes cells and brains and free will. Fundamentally, you’re all just a lot of interacting particles. Get over it. "<br /><br />If we made even one iota of progress on the hard problem of consciousness, to the "best of our knowledge" might actually mean something. But, we haven't, and it doesn't. This statement is as much "Anonymoushttps://www.blogger.com/profile/02260017465845457855noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-83117583492200357272016-12-01T10:36:49.632-05:002016-12-01T10:36:49.632-05:00David,
Not very much. See, nobody knows how to ap...David,<br /><br />Not very much. See, nobody knows how to apply this (so-far very immature) model to quantum systems. Any such conclusions hence relies on additional assumptions. What you then show is that either the original model or the additional assumptions are incorrect, which isn't much of a statement. Honestly, I have forgotten the details, but I read the papers on that when they came Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-73505448255155522292016-12-01T09:43:04.580-05:002016-12-01T09:43:04.580-05:00Dear Bee, you mention the possible promise of the ...Dear Bee, you mention the possible promise of the research approach largely stimulated by Jacobson's seminal paper that suggests the GR Field Equations are essentially a thermodynamic equation of state - which, ala Verlinde, leads to gravity being possibly considered as an 'entropic force'. What do you think about the claim that experimental results on cold neutrons in a gravitationalAnonymoushttps://www.blogger.com/profile/14318195499972536515noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-88817677226611353212016-12-01T08:31:47.868-05:002016-12-01T08:31:47.868-05:00naivetheorist,
You have made a statement I regard...naivetheorist,<br /><br />You have made a statement I regard irrelevant and I have very unemotionally told you that I think it's irrelevant. As response you complain I'm the one being emotional. Speak of projection. <br /><br />Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-75137527427730882682016-12-01T05:51:31.720-05:002016-12-01T05:51:31.720-05:00B:
"I don't really care what type of the...B:<br /><br />"I don't really care what type of theories you prefer and I don't know how that's relevant for anything.". why do you feel it is necessary or useful to make snarky responses (or do you not realize that your comments can be viewed this way)? such attacks (like Trump's tweets) only make you come across as being both petty and nasty. you might want to try to naivetheoristhttps://www.blogger.com/profile/00425164894020381981noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-29185984083499290712016-12-01T05:34:56.958-05:002016-12-01T05:34:56.958-05:00Uh oh.. yeah..apologies I'd written the questi...Uh oh.. yeah..apologies I'd written the question at an airport while waiting on someone Synchlavierhttps://www.blogger.com/profile/07839149311317002097noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-74772650609351767412016-12-01T05:31:11.750-05:002016-12-01T05:31:11.750-05:00naivetheorist,
You misread my statement. I explic...naivetheorist,<br /><br />You misread my statement. I explicitly explained in the first sentence what the "emergent" means in "emergent gravity" and in the second sentence what we mean by that in theoretical physics. Yes, there are a few physicists who indeed manage to believe in strong emergence. As they say, exceptions prove the rule. I elaborated on the distinction between Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-60960584891756019242016-12-01T04:27:18.384-05:002016-12-01T04:27:18.384-05:00sabine:
"The “emergent” means that gravity i...sabine:<br /><br />"The “emergent” means that gravity isn’t fundamental, but instead can be derived from some underlying structure. That’s what we mean by “emergent” in theoretical physics: If theory B can be derived from theory A but not the other way round, then B emerges from A.". i know you don't want to engage on a discussion about emergence but you should at least define it naivetheoristhttps://www.blogger.com/profile/00425164894020381981noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-62191971756135664262016-12-01T04:16:11.581-05:002016-12-01T04:16:11.581-05:00I am eagerly awaiting your opinion on Erik Verlind...I am eagerly awaiting your opinion on Erik Verlinde's new paper. It made quite a splash over here in the Netherlands. Even outside theoretical physics, or physics as such. But his 2010 paper too made the newspapers, be it in 2009 even before he had written it down. <br />Rob van Son (Not a physicist, just an amateur)https://www.blogger.com/profile/12611755507524401026noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-36871750896321792822016-12-01T02:19:26.428-05:002016-12-01T02:19:26.428-05:00Synchlavier,
The blog is the full website. As in ...Synchlavier,<br /><br />The blog is the full website. As in "I am writing a blog." The "log" in "blog" stands for "log". The individual entries are blogposts, or articles or threads or essays or call them what you wish, but don't call them "blog." <br /><br />Gravitons are the weak-field limit. Finding a graviton might or might not tell you Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-37494950717928901132016-12-01T01:46:56.781-05:002016-12-01T01:46:56.781-05:00While on that note I wonder if you've written ...While on that note I wonder if you've written a blog on why confirmation of the existence of gravitons the quanta of gravity waves in and of itself would still not yield to a theory of quantum gravitySynchlavierhttps://www.blogger.com/profile/07839149311317002097noreply@blogger.com