tag:blogger.com,1999:blog-22973357.post3802661997771153796..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: The Oscillating UniverseSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger19125tag:blogger.com,1999:blog-22973357.post-71906344868081990712011-12-10T05:47:30.025-05:002011-12-10T05:47:30.025-05:00Hi Giotis,
I had seen it and marked it for readin...Hi Giotis,<br /><br />I had seen it and marked it for reading. However, it will take a while till I will find the time. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-90699457288421780012011-12-10T03:59:01.063-05:002011-12-10T03:59:01.063-05:00Related subject: Bee did you check Bojowald's ...Related subject: Bee did you check Bojowald's latest paper http://arxiv.org/abs/1112.1899 ? Due to holonomy corrections there is a signature change near the big bang singularity and thus a transition from Euclidean to Lorentzian regime. This is exactly what the Hartle-Hawking wave function postulates i.e. that the Euclidean space is the fundamental one and there was a signature change from Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-42987361526342113622011-11-20T05:27:38.545-05:002011-11-20T05:27:38.545-05:00I don't, but I know people who do.I don't, but I know people who do.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-58647481197945044332011-11-20T05:25:54.550-05:002011-11-20T05:25:54.550-05:00Ok but do you really believe that something that h...Ok but do you really believe that something that has lost its physical meaning already in the derived classical world will aquire it in the fundamental theory?Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-91129336122345822522011-11-20T04:55:46.917-05:002011-11-20T04:55:46.917-05:00Yes. What I mean is that GR is probably not the fu...Yes. What I mean is that GR is probably not the fundamental theory of space and time, and thus fundamentally we don't actually know what time is. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-81901316272252951622011-11-20T04:53:42.455-05:002011-11-20T04:53:42.455-05:00Not sure what you mean Bee. The fact that the time...Not sure what you mean Bee. The fact that the time you are talking about (as a coordinate of a background spacetime manifold) is just a parameter with no physical significance is an old lesson of GR.Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-33899660147787317212011-11-18T19:09:21.778-05:002011-11-18T19:09:21.778-05:00You're welcome Bee, and I'm sure Piper was...You're welcome Bee, and I'm sure Piper was trying to make a point. A rather nice take on the original. Totally random I only bought one Gardner book and I came across the original. Serendipity? <br /><br />In any event, I see you have a new post up re ....wot's this?? ... lesbian erotica and wet t-shirt contests?? Naughty Bee... tell us more. :-)Steven Colyerhttps://www.blogger.com/profile/10435759210177642257noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-36309388108858781092011-11-18T08:09:42.661-05:002011-11-18T08:09:42.661-05:00I am not sure if some of you people have heard of ...I am not sure if some of you people have heard of the <a href="http://eskesthai.blogspot.com/2011/11/occupy-wall-street.html" rel="nofollow">Wayback Machine</a>?<br /><br />You cannot erase the future by eliminating the past?:)If you did you might call it something else but it's roots will have already bee established? <br /><br />The only thing you can do is if you were in opposition is to PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-9618660491063469932011-11-18T01:23:04.343-05:002011-11-18T01:23:04.343-05:00Hi Steven,
Thanks for that! This is funny, I also...Hi Steven,<br /><br />Thanks for that! This is funny, I also came across the story in a book (JD Barrow, Impossibility), but neither in that book, nor in the source I linked to above is there any mentioning of Brown's story. In Piper's version the oscillation seems to be not simply periodic, maybe he was trying to make a point with that? Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-48723724380421613312011-11-17T23:03:22.426-05:002011-11-17T23:03:22.426-05:00On page 43, The New Ambidextrous Universe, by Mart...On page 43, The New Ambidextrous Universe, by Martin Gardner:<br /><br />Frederic Brown has the distinction of having written an entire short short that is palindromic by words. He has given permission to reprint it in full, from his collection of outlandishly funny stories <i>Nightmares and Geezenstacks</i> (Bantam, 1961).<br /><br /><b>THE END<br /><br />Professor Jones had been working on timeSteven Colyerhttps://www.blogger.com/profile/10435759210177642257noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-76817430819442576752011-11-17T23:01:29.107-05:002011-11-17T23:01:29.107-05:00This comment has been removed by the author.Steven Colyerhttps://www.blogger.com/profile/10435759210177642257noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-11568010799487060682011-11-17T22:52:36.094-05:002011-11-17T22:52:36.094-05:00Found it! Original version from 1961 IS a palindro...Found it! Original version from 1961 IS a palindrome. Typing it now ...Steven Colyerhttps://www.blogger.com/profile/10435759210177642257noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8208400318097770122011-11-17T20:25:06.781-05:002011-11-17T20:25:06.781-05:00I saw this in one of my books, not sure it's q...I saw this in one of my books, not sure it's quoted correctly but the version you have is still good, brb ...Steven Colyerhttps://www.blogger.com/profile/10435759210177642257noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-20586712735128090962011-11-15T17:33:07.714-05:002011-11-15T17:33:07.714-05:00http://arxiv.org/abs/1110.5019
http://arxiv.org/ab...http://arxiv.org/abs/1110.5019<br />http://arxiv.org/abs/1106.4859<br />Equation 1<br /><br />The bouncing universe, albeit with spacetime torsion not curvature. Space has no intrinsic chiral discrimination toward mass.<br /><br />http://www.quantumdiaries.org/2011/11/14/lhcb-reports-observation-of-cp-violation-in-charm-welcome-new-physics-or-not/<br />Doesn't count.Uncle Alhttps://www.blogger.com/profile/05056804084187606211noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-135134774603891062011-11-15T07:12:15.912-05:002011-11-15T07:12:15.912-05:00Hi Bee,
I think the field time represents is a fi...Hi Bee,<br /><br />I think the field time represents is a field of dreams, as it was always here and it is us who then were able to come.<br /><br /><i><b>“Time present and time past<br />Are both perhaps present in time future,<br />And time future contained in time past.<br />If all time is eternally present<br />All time is unredeemable”</b></i><br /><br />-T.S Elliot , “Burnt Norton” (1935)<Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-78295794629302978032011-11-15T06:06:15.149-05:002011-11-15T06:06:15.149-05:00Well, yes and no, depends on what you mean with ti...Well, yes and no, depends on what you mean with time. If time 'is' just a parametrization it is replacable by some other parameterization that might also be a field, in particular you can replace any appearance of time that way, though it's not very practical in most circumstances. If time 'is' more than that, then not. To see what I mean, is there time if you have no matter Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-48042740908028899172011-11-15T05:35:06.076-05:002011-11-15T05:35:06.076-05:00"Time is a field. I have made this machine wh..."Time is a field. I have made this machine which reverses the field."<br /><br /><br />Correct. In quantum cosmology time is a field. A massless scalar field or the scale factor is used as internal time with respect to which things evolve. I guess if you could reverse them the universe would start contracting. For the scale factor this is a tautology:-)Giotishttps://www.blogger.com/profile/03594944884584261018noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-2249155105750497712011-11-15T01:23:55.820-05:002011-11-15T01:23:55.820-05:00:-) The Oscillation would have been funnier even a...:-) The Oscillation would have been funnier even as a Palindrome. Do geese see God? And what about the past hypothesis? Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-2297006665555545942011-11-14T18:33:33.785-05:002011-11-14T18:33:33.785-05:00Time troubles me. Me troubles time.Time troubles me. Me troubles time.Christine Cordula Dantashttps://www.blogger.com/profile/05271747374185459530noreply@blogger.com