tag:blogger.com,1999:blog-22973357.post8453421766183503897..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: Recreating the Big Bang?Sabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger25125tag:blogger.com,1999:blog-22973357.post-11096149675639432832018-12-06T15:10:46.963-05:002018-12-06T15:10:46.963-05:00Since we are in fact quite clever, we accelerate i...Since we are in fact quite clever, we accelerate isotopically pure 208 Pb in the LHC,jmj2001https://www.blogger.com/profile/10759011542358824635noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-45387022088273242672009-07-28T05:55:00.009-04:002009-07-28T05:55:00.009-04:00Dear Stefan,
I did try contacting the authors of t...Dear Stefan,<br />I did try contacting the authors of that paper, without luck. It's perhaps understandable, since the work is 10 years old.<br />Thanks for responding, I'll follow your advice.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-1153909654097780252009-07-27T16:12:35.849-04:002009-07-27T16:12:35.849-04:00Hi anonymous,
My argument is that their abundanc...Hi anonymous,<br /><br /><i>My argument is that their abundance IS small, but definitively non-zero, and seems to increase with energy. ... My point is: although individual light nuclei would (indeed) have a small survival rate, their overall abundance at those temperatures would not be zero, and may even increase with energy.</i><br /><br />True, besides just the binding energy, there are otherstefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-3059850661015938212009-07-27T07:25:34.942-04:002009-07-27T07:25:34.942-04:00Dear Stefan,
At the T = 10 MeV limit (LHS of the r...Dear Stefan,<br />At the T = 10 MeV limit (LHS of the referred BBNS figure) photon disintegration is said to be responsible for the small amount of d, and A=3 nuclei. My argument is that their abundance IS small, but definitively non-zero, and seems to increase with energy. The pion-pair production channel opens up at E = 240 MeV, although (sure) at T = 150 MeV the thermal-tail contribution Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-91456159686762692012009-07-24T17:16:18.840-04:002009-07-24T17:16:18.840-04:00Hi anonymous,
anything wrong in extrapolating the...Hi anonymous,<br /><br /><i>anything wrong in extrapolating the p,n,d and A=3 curves to 150 MeV?</i> <br /><br />... well, at around 150 MeV at latest, the quark-gluon substructure comes into play, but even before, there should be thermal pions around in non-negligible numbers. <br /><br />I really doubt how bound nuclei can be stable in these conditions - especially deuterons, with a binding stefanhttps://www.blogger.com/profile/09495628046446378453noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-58118932678391306932009-07-23T12:34:08.461-04:002009-07-23T12:34:08.461-04:00The following link:
http://arxiv.org/abs/astro-ph/...The following link:<br />http://arxiv.org/abs/astro-ph/9903300<br />on pg. 11 has an interesting figure representing the BBNS time/temperature evolution for light nuclei. The highest<br />temperature is roughly equivalent to 10 MeV (LHS of the figure) . <br />Question: you see anything wrong in extrapolating the p,n,d and A=3 curves to 150 MeV? The physics shouldn't change much. The Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-88388029262570636442008-07-12T12:05:00.000-04:002008-07-12T12:05:00.000-04:00It is necessary unfortunately to have to go even f...It is necessary unfortunately to have <A HREF="http://eskesthai.blogspot.com/2008/07/geologist-and-mathematician.html" REL="nofollow" TITLE="The Geologist and the Mathematician">to go even further</A> from this post by you Bee:)An attempt by a layman for sure.:)<BR/><BR/>While one might think they are exempt from such "ism's" unfortunately "by association in post topic," such a view should be PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-20486924210541539272008-07-08T04:33:00.000-04:002008-07-08T04:33:00.000-04:00Hi Coraifeartaigh,Yes, I guess the problem is on b...Hi Coraifeartaigh,<BR/><BR/>Yes, I guess the problem is on both sides of the communication. But instead of blaming each other, we should try to improve the situation.<BR/><BR/><I>I suspect the confusion of LHC energy with BB is partly reponsible for the BH scaremongering..</I><BR/><BR/>It didn't cross my mind there could be a relation between the two, do you really think so?<BR/><BR/>Best,<BR/><Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-19739369399346474982008-07-07T13:45:00.000-04:002008-07-07T13:45:00.000-04:00Hey Bee,I'm not a science journalist either!Re mak...Hey Bee,<BR/>I'm not a science journalist either!Re making the minimum effort at understanding, I think you're broadly right, but have defnitely come across this issue as a genuine misunderstanding more than once. <BR/><BR/>I guess like most teachers, I tend to blame myself if those I'm trying to inform misunderstand - it's easy to make statements that are ambiguous / misleading. <BR/><BR/>It's Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-88891565540011316302008-07-07T10:20:00.000-04:002008-07-07T10:20:00.000-04:00A black hole has a finite diameter measured from o...A black hole has a finite diameter measured from outside its event horizon but a[near(?])n infinite diameter measured inside. The LHC is therefore a tardis creator. CERN secretly hopes to sell sonic screw drivers.<BR/><BR/>Accelerating polyisotopic lead is not clever (plus Enviro-whiner jabber about toxic vacua). Naturally monoisotopic gold or bismuth would be clever.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-42721471712181109382008-07-07T10:03:00.000-04:002008-07-07T10:03:00.000-04:00The Pierre Auger Observatory in Malargue, Argentin...<I><A HREF="http://astro.uchicago.edu/cosmus/projects/auger/" REL="nofollow">The Pierre Auger Observatory in Malargue, Argentina,</A> is a multinational collaboration of physicists trying to detect powerful cosmic rays from outer space. The energy of the particles here is above 1019eV, or over a million times more powerful than the most energetic particles in any human-made accelerator. No-one PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-19141822120253401252008-07-07T10:02:00.000-04:002008-07-07T10:02:00.000-04:00Hi Plato,You don't have to apologize for being a l...Hi Plato,<BR/><BR/>You don't have to apologize for being a layman, but I can't answer questions if I don't know what the question is. Yes, the LHC will produce muons. <A HREF="http://visits.web.cern.ch/visits/guides/tools/manual/images/atlasoverview.JPG" REL="nofollow">See these funny looking caps of ATLAS?</A> They are part of the muon detector. Best,<BR/><BR/>B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-40735598136999372102008-07-07T09:48:00.000-04:002008-07-07T09:48:00.000-04:00Layman apologies:) You don't have to answer any mo...Layman apologies:) You don't have to answer any more if you don't like too.:)<BR/><BR/><I><A HREF="http://bp0.blogger.com/_cldxKGOzgeM/RbBTZya_AiI/AAAAAAAAABg/2oqAg6_U7N0/s320/cosmic+ray.gif" REL="nofollow">Cosmic rays</A> are caused by protons from outer space. When a proton (shown in yellow) hits the air in the earth's upper atmosphere it produces many particles. Most of these decay or are PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-68927523991297882562008-07-07T09:36:00.001-04:002008-07-07T09:36:00.001-04:00I don't know what's wrong with the recent comments...I don't know what's wrong with the recent comments applet.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-34953360029951345752008-07-07T09:36:00.000-04:002008-07-07T09:36:00.000-04:00Plato: It would really help if you could be more p...Plato: It would really help if you could be more precise, I neither have the time nor the patience to guess around. This picture you link to with an incredibly bad resolution could<BR/><BR/>a) Show an incoming cosmic ray that creates a shower by scattering on something in the Earth's atmosphere. It neither says what the incoming particle is in this case, nor what it hits in the primary collision,Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-76659272105480640372008-07-07T09:27:00.000-04:002008-07-07T09:27:00.000-04:00SimulateThese are aspects of the standard model ar...<A HREF="http://bp2.blogger.com/_cldxKGOzgeM/RuKu4_rrIXI/AAAAAAAAAio/HRnTDwx5ARc/s200/cosmic.jpg" REL="nofollow">Simulate</A><BR/><BR/>These are aspects of the standard model are they not?<BR/><BR/>What's with the "recent comment" section on the right hand side?PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-30709664665251657172008-07-07T09:17:00.000-04:002008-07-07T09:17:00.000-04:00depends on what you mean with 'cosmic particle col...depends on what you mean with 'cosmic particle collisions' or 'simulate'. The LHC is supposed to collide pp at 14 TeV, and PbPb at 1150 TeV, period.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-83818174537886933142008-07-07T08:57:00.000-04:002008-07-07T08:57:00.000-04:00That's not what I was asking Bee:)Does the LHC "si...That's not what I was asking Bee:)<BR/><BR/>Does the LHC "simulate" cosmic particle collisions?PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-88617914335974185472008-07-07T08:31:00.000-04:002008-07-07T08:31:00.000-04:00"I suspect that there is just little motivation to..."I suspect that there is just little motivation to actually get things right, but instead there is an emphasize on advertising and entertaining, and the more bang the better."<BR/><BR/>It's about making money. The exact reason why so-called cosmological "implications" of high energy physics research are eagerly hyped by the media was explained by Jeremy Webb, former BBC sound engineer and now nigehttps://www.blogger.com/profile/03402194253543690982noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-84449601997113818172008-07-07T07:59:00.000-04:002008-07-07T07:59:00.000-04:00Plato, please read point 1. A collision of element...Plato, please read point 1. A collision of elementary particles doesn't create a hot and dense plasma for the same reason a grain of sand doesn't make a beach.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-7447861730617044832008-07-07T07:50:00.000-04:002008-07-07T07:50:00.000-04:00Hi Coraifeartaigh,I understand that it must be dif...Hi Coraifeartaigh,<BR/><BR/>I understand that it must be difficult to be a science journalist and to find the right amount of details that can sensibly be communicated in popular writing. But I am really tired of hearing excuses like this. If a journalist doesn't know what energies 'not seen since the Big Bang' means, he or she should ask and clarify and not fantasize. Besides this, it isn't hardSabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-19132263232014640132008-07-07T07:30:00.000-04:002008-07-07T07:30:00.000-04:00Hi Bee and Stefan,Just as another side remark, whi...Hi Bee and Stefan,<BR/><BR/>Just as another side remark, which is how can one logically justify statements like ‘exploring energies not seen since the beginning of the universe’ with ‘not worrying about the energies created for they are far exceeded by everyday cosmic ray events’. Like the old saying goes, ”one cannot suck and blow at the same time”:-)<BR/><BR/>Best,<BR/><BR/>PhilPhil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-42333367249652378682008-07-07T07:03:00.000-04:002008-07-07T07:03:00.000-04:00Hi Bee and Stefan,Nice piece, this recreating the ...Hi Bee and Stefan,<BR/><BR/>Nice piece, this recreating the early universe stuff is obviously what makes for good headlines and was never intended to be good science. Also it is probably considered by even those involved as what’s required in selling the public on the exspendager being justified. To describe it as simply a better microscope just isn’t sexy enough I’m afraid for those that have Phil Warnellhttps://www.blogger.com/profile/15671311338712852659noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-39759910438040384812008-07-07T06:36:00.000-04:002008-07-07T06:36:00.000-04:00Hi Bee and Stefan,I think there is a very simple e...Hi Bee and Stefan,<BR/>I think there is a very simple explanation for this confusion, as somone who dabbles a little in science journalism.<BR/><BR/>The problem is that scientists frequently make statements like "such and such an accelerator will re-create energies not seen since the Big Bang". Not technically incorrect, but misleading.. <BR/><BR/>It is not made clear to journalists that what is Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-79846590435952344132008-07-07T06:16:00.000-04:002008-07-07T06:16:00.000-04:00How about cosmic particle collisions?How about cosmic particle collisions?Anonymousnoreply@blogger.com