tag:blogger.com,1999:blog-22973357.post6423930504065854843..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: Book review: “Time Reborn” by Lee SmolinSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger39125tag:blogger.com,1999:blog-22973357.post-13252991780253641042013-05-06T09:33:33.306-04:002013-05-06T09:33:33.306-04:00Hi Bee,
Definitely looking for the right answers ...Hi Bee,<br /><br />Definitely looking for the right answers and any help is much appreciated. Thanks.<br /><br />I did come across this, "<a href="http://physics.stackexchange.com/questions/1073/how-does-classical-gr-concept-of-space-time-emerge-from-string-theory?lq=1" rel="nofollow">How does classical GR concept of space-time emerge from string theory?</a><br /><br />So definitely, what I PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-28791097974123118142013-05-06T02:35:43.467-04:002013-05-06T02:35:43.467-04:00Plato,
I think you're confusing special with g...Plato,<br />I think you're confusing special with general relativity. It's special relativity which introduced space-time, which presently is a fundamental ingredient in all our theories and which is the basis of the idea that 'everything is relative', ie absolute space has no meaning, it's all in the relations etc. Special relativity is not emergent in string theory. General Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-47511384612927771732013-05-06T00:59:44.860-04:002013-05-06T00:59:44.860-04:00More on Smolin and time:
http://www.closertotruth...More on Smolin and time:<br /><br />http://www.closertotruth.com/topic/Is-Time-Real-/187<br />http://www.closertotruth.com/participant/Lee-Smolin/96<br /><br /><br />Plato,<br />"I would need somebody who is well versed in string theory to respond to that accusation." Me too, ...<br /><br />Best.<br />MarkusMhttps://www.blogger.com/profile/03431499396962852389noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-21416292153360374822013-05-05T11:13:58.600-04:002013-05-05T11:13:58.600-04:00Or you can try this locationOr you can try <a href="http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&sqi=2&ved=0CDsQFjAC&url=http%3A%2F%2Ftimereborn.com%2Fwp%2Fwp-content%2Fuploads%2F2013%2F04%2FNature-review-of-TR-4-24-13.pdf&ei=yXaGUc_uOqmajAKNj4HgAw&usg=AFQjCNEyHZJNHJSn0qwpbBAfGvjlQVFntQ&sig2=WJ2WOKjh_WF3eP3zW5Tw0A" rel="nofollow">this location</a>PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-37292612068855099252013-05-05T04:05:46.497-04:002013-05-05T04:05:46.497-04:00I saw today that there is a review of this book in...I saw today that there is a review of this book in the recent issue of Nature by Pedro Ferreira: <a href="http://www.nature.com/nature/journal/v496/n7446/full/496430a.html" rel="nofollow">Clockwork Cosmos</a> (subscription only). It is quite similar to my review, he concludes<br /><br />"Even as I mentally argued with this book, I kept on ploughing through to see how Smolin dealt with the Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-58850969823344842942013-05-04T22:22:32.341-04:002013-05-04T22:22:32.341-04:00It is certainly true that both space and time (or ...It is certainly true that both space and time (or space-time) are determined, not by external and eternal space and time coordinates, but by matter and the various material relationships existing in the universe. This was a powerful insight of relativity theory, and also, incidentally, the basis for the pictorial "research" of artists such as Cezanne, Picasso, Braque and Mondrian, for DocGhttps://www.blogger.com/profile/17359004200002936544noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-83220162949656610432013-05-04T22:13:04.740-04:002013-05-04T22:13:04.740-04:00Hi Bee,
Just to have know that I just finished re...Hi Bee,<br /><br />Just to have know that I just finished reading the book, with my initial realization is in now knowing that it’s certainly not finished with me. <br /><br />Best,<br /><br />Phil<br />Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-35523827958746674962013-05-04T19:04:43.584-04:002013-05-04T19:04:43.584-04:00If space and time, or space-time, are/is relationa...If space and time, or space-time, are/is relational, then if matter is removed there is nothing to relate to. Without objects the concept distance has no reality.Robert L. Oldershawhttps://www.blogger.com/profile/15396555790655312393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-84802410974491404792013-05-04T13:36:29.527-04:002013-05-04T13:36:29.527-04:00Hi MarkusM,
"Formerly it was believed that i...Hi MarkusM,<br /><br />"<i>Formerly it was believed that if all things vanish from this world, space and time would remain, but according to the theory of relativity, space and time vanish together with all things.</i>"<br />- <b>Albert Einstein</b> 1921 <br /><br />Your last quote would fall into a certain category with respect to Lee Smolin's book, and with respect to what PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-68141905197031793462013-05-04T02:44:24.911-04:002013-05-04T02:44:24.911-04:00T h ray,
at least at some time Einstein held the ...T h ray, <br />at least at some time Einstein held the following view, which I find quite remarkable:<br />"Formerly it was believed that if all things vanish from this world, space and time would remain, but according to the theory of relativity, space and time vanish<br />together with all things."<br />- Albert Einstein 1921 MarkusMhttps://www.blogger.com/profile/03431499396962852389noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-60362840040499527732013-05-03T14:29:33.154-04:002013-05-03T14:29:33.154-04:00Bee,
I have the book on Kindle, though I have not...Bee,<br /><br />I have the book on Kindle, though I have not gotten far into it. I'm finding the reviews very interesting, though!<br /><br />Allow me to speculate that what Lee means by real is what Einstein meant by "physically real:" " ... independent in its properties, having a physical effect but not itself influenced by physical conditions."<br /><br />In general t h rayhttps://www.blogger.com/profile/00150085167540063914noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-69596529249579752662013-05-02T13:36:06.851-04:002013-05-02T13:36:06.851-04:00Hi Bee,
TyTung: P.S. I am not defending Platonism...Hi Bee,<br /><br /><b>TyTung</b>: <i>P.S. I am not defending Platonism, I am just questioning a possible categorical mistake in his argument.</i> <br /><br />I have been dealing from this perspective as well, so what you offer Bee as explanation to tytung still to me has to be considered.<br /><br />I will say there is a cultural perspective here(Science in society perspective holding 3%), PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-57514647747653578462013-05-02T11:19:55.924-04:002013-05-02T11:19:55.924-04:00Without wishing to upset you further, let me just ...<br />Without wishing to upset you further, let me just explain my general policy regarding new ideas.<br /><br />I ask the author to: First - "Show Me The Predictions!"<br /><br />When I see them I have a better feeling for whether or not to invest time in studying the new idea.<br /><br />With so much crackpottery and pseudo-science coming at us from professionals and amateurs alike,Robert L. Oldershawhttps://www.blogger.com/profile/15396555790655312393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-50227513881817495822013-05-02T03:55:59.069-04:002013-05-02T03:55:59.069-04:00Concerning platonism, emergence, etc., Witten late...Concerning platonism, emergence, etc., Witten lately gave a very interesting interview here:<br />http://www.wissenschaft.de/wissenschaft/inhalt/aktuelles_heft.html<br /><br />E.g. <br />"Sie sind auch ein großer Mathematiker. Existieren algebraische und geometrische Systeme für Sie absolut und an sich, oder halten Sie diese für nützliche Instrumente und Erfindungen?"<br /><br />"MarkusMhttps://www.blogger.com/profile/03431499396962852389noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-69593082405757661292013-05-02T03:43:47.989-04:002013-05-02T03:43:47.989-04:00Hi Tytung,
I disagree that "outside" is...Hi Tytung,<br /><br />I disagree that "outside" is a relation between two physical systems, though the word arguably has its origin in a physical image. I would suggest you replace it with "not part of" or something else that doesn't suggest a location. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-58099921244332333502013-05-02T03:40:17.040-04:002013-05-02T03:40:17.040-04:00Robert,
Are you really telling me you are not abl...Robert,<br /><br />Are you really telling me you are not able to a) look at Lee's Wikipedia page and find <a href="http://en.wikipedia.org/wiki/The_Life_of_the_Cosmos" rel="nofollow">the one book among a total of four that explains his idea in great detail</a> and b) Do a search for "cosmological natural selection" on the arxiv, which would have lead you <a href="http://arxiv.org/Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-71126927731055908512013-05-02T02:48:25.596-04:002013-05-02T02:48:25.596-04:00Hi Bee,
No, it is not part of the physical univer...Hi Bee,<br /><br />No, it is not part of the physical universe. <br /><br />But what I was saying is that even if there is a Platonic realm of abstract mathematical entities, since it is not physical we cannot say it lies outside of our physical universe. <br />"Outside" is a relationship between two physical systems.<br />But Smolin seems to be using this point to argue for the tytunghttps://www.blogger.com/profile/05777947785613061617noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-66553601296921858372013-05-01T22:37:33.394-04:002013-05-01T22:37:33.394-04:00If Smolin's ideas led to a first-rate predicti...<br />If Smolin's ideas led to a first-rate prediction that would offer a definitive test of his ideas, I think the response would have readily identified that prediction.<br /><br />I strongly suspect that Smolin's predictions regarding his cosmological musings are of the plastic variety that have become so popular over the last 40 years. Sort of like: 'One prediction can shape-shiftRobert L. Oldershawhttps://www.blogger.com/profile/15396555790655312393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-22817742118870506462013-05-01T12:20:53.651-04:002013-05-01T12:20:53.651-04:00/*What does he mean when he says the vast majority.../*What does he mean when he says the vast majority of physicists think time is emergent*/<br /><br />It's just "politically correct" replacement for aether model, in which every object is composed from many others in emergent way, i.e. like density fluctuations of gas. Or at least I don't know about any better physically relevant example of emergence. Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-60311341335031977392013-05-01T12:15:34.329-04:002013-05-01T12:15:34.329-04:00/*seemingly puzzling fact that mathematical truth .../*seemingly puzzling fact that mathematical truth is eternal and timeless, while the world that physicists are trying to describe with that mathematics isn’t.*/ <br /><br />It just indicates, that the <a href="http://www.harpers.org/archive/2011/12/0083720" rel="nofollow">math cannot be</a> the complete/exact description of reality. Regarding the atemporal universe, the space concept is closely Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-26670129395067845012013-05-01T11:24:06.526-04:002013-05-01T11:24:06.526-04:00Hi Rastus,
Yes, "emergent" and also &qu...Hi Rastus,<br /><br />Yes, "emergent" and also "complex" have become very fashionable words, and they are frequently used quite sloppily without much content. However, physicists normally use the word with a quite clear meaning. It is commonly used to describe properties of a system that do not make sense, or do not even exist, at the fundamental level (degrees of freedom) butSabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-90787427708595581022013-05-01T11:04:48.976-04:002013-05-01T11:04:48.976-04:00Hi Tytung,
I don't know what you mean when yo...Hi Tytung,<br /><br />I don't know what you mean when you say "truth" could be "mental". Mental processes are for all we know consequences of the fundamental interactions of particles in the standard model. The standard model is a mathematical theory. So forget about "mental": is this mathematics part of our universe or isn't it? Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-74588006429764412842013-05-01T11:01:32.532-04:002013-05-01T11:01:32.532-04:00Hi Robert,
Lee has written a whole book about his...Hi Robert,<br /><br />Lee has written a whole book about his idea cosmological natural selection (changing laws), and there's half a dozen or so of papers on the arxiv about the predictions, you'll manage to find references if you care to look. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-31994858866512125012013-05-01T10:59:21.850-04:002013-05-01T10:59:21.850-04:00Hi Giotis,
I presently can't recall anything ...Hi Giotis,<br /><br />I presently can't recall anything about Aachen, but that doesn't mean I haven't been there (my mother tends to know this better than me). I'm scheduled for a seminar there in July. My semi-sarcastic remark about the string theorists referred to those who criticized Lee's last book but didn't find it necessary to read it. They'll probably hate thisSabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-23525588263505544642013-04-30T21:23:23.064-04:002013-04-30T21:23:23.064-04:00Are there ways to test Smolin's ideas, such as...<br />Are there ways to test Smolin's ideas, such as the main one that basic laws change with time.<br /><br />Is this discussed in the book?Robert L. Oldershawhttps://www.blogger.com/profile/15396555790655312393noreply@blogger.com