tag:blogger.com,1999:blog-22973357.post6655841972034673100..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: Can we probe planck-scale physics with quantum optics?Sabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger16125tag:blogger.com,1999:blog-22973357.post-84541637777918025612012-08-26T05:28:47.599-04:002012-08-26T05:28:47.599-04:00There is one more interesting proposition for prob...There is one more interesting proposition for probing which has gone undetected for more than 1o years now! <br /><br />http://iopscience.iop.org/0264-9381/18/8/308/<br /><br />For some strange reason, Kingsley's work on the possible role of non-linearities in Q. Gravity has also been overlooked.Theophanes Raptishttps://www.blogger.com/profile/01269614280130174555noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-89095345886272406522012-06-26T08:17:07.082-04:002012-06-26T08:17:07.082-04:00Hi Caslav,
What is "noncollegial" about...Hi Caslav,<br /><br />What is "noncollegial" about my answer? If I think something is wrong, please allow me to say it is wrong. <br /><br /><i>"you say that an initial increase followed by a saturation or decrease for higher orders cannot be. Our attitude is that only empirical observations can back up such claims."</i><br /><br />You misunderstood what I said. I did not say Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-76948324722248657822012-06-26T07:56:59.846-04:002012-06-26T07:56:59.846-04:00Dear Sabine,
For the sake of the interested reade...Dear Sabine,<br /><br />For the sake of the interested reader I will comment on the points you raise, and ignore the noncollegial sections in your answer. You mention interpretational issues as if they are facts, but there is no consensus whatsoever as to how to construct a theory with modified commutators. You say that they should be exclusively applied to "fundamental" degrees of Caslav Bruknerhttps://www.blogger.com/profile/11966531601569609147noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-7987897656702000352012-06-25T09:21:40.473-04:002012-06-25T09:21:40.473-04:00Hi Caslav,
Thanks for your comment. What you say ...Hi Caslav,<br /><br />Thanks for your comment. What you say is simply wrong and just reinforces my impression that you don't know very much about the theory you are dealing with. How the collective degrees of freedom arise from the fundamental ones is *the* decisive question to decide whether the experiment you propose will be able to test any interesting range of parameter space, because theSabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8874568505737469192012-06-24T13:35:06.043-04:002012-06-24T13:35:06.043-04:00Dear Sabine,
I read your blog entry on Pikovski...Dear Sabine, <br /> <br />I read your blog entry on Pikovski et. al. “Probing Planck-scale physics with quantum optics” with great interest. I would like to make the following comments that hopefully clarify the motivation and the analysis behind our paper.<br /><br />1. It is incorrect that we assume that the centre of mass degree of freedom is given as a linear (or any other) sum of momenta of Caslav Bruknerhttps://www.blogger.com/profile/11966531601569609147noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-17412259070673537552012-04-28T00:15:00.062-04:002012-04-28T00:15:00.062-04:00Hi SGielen,
You call it not too compelling, but i...Hi SGielen,<br /><br />You call it not too compelling, but it has the side-effect of amplifying "Planck scale effects" in composite systems. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-41138801136541925652012-04-27T12:34:04.070-04:002012-04-27T12:34:04.070-04:00What are Particle Constructs?
You have to be able...What are <a href="http://www.eskesthai.com/2012/04/several-large-experimental-groups-are.html" rel="nofollow">Particle Constructs?</a><br /><br />You have to be able to slot particle expressions in between energy valuations? You use what you need for further experimentation.<br /><br />Best,PlatoHagelhttps://www.blogger.com/profile/00849253658526056393noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-74734710033670133922012-04-27T10:39:42.254-04:002012-04-27T10:39:42.254-04:00I'm not familiar with all of the (vast) litera...I'm not familiar with all of the (vast) literature on this, the papers I have looked at avoid discussing composite systems. It shouldn't be too difficult to cook up a coproduct that allows you to maintain the same modified commutator for composite systems, but I think this just moves the problem to a different place: Deviations of such a coproduct from the standard one should scale with EAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-5417758591795516862012-04-26T01:08:11.281-04:002012-04-26T01:08:11.281-04:00Hi SGielen,
Yes, I agree with you, the coproduct ...Hi SGielen,<br /><br />Yes, I agree with you, the coproduct is the issue. <br /><br />Well, I did write a comment to the editor... Several weeks ago already. I posted this here because I didn't get a reply and was frustrated. <br /><br />However, it seems I wasn't patient enough because just yesterday I got a reply from the editor. It seems they took my comment very seriously and did Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-66585342251297831452012-04-25T21:06:53.094-04:002012-04-25T21:06:53.094-04:00Never mind Lorentz invariance, what about composit...Never mind Lorentz invariance, what about composite systems? I ought to have a modified coproduct structure in order to make the commutation relations consistent -- or, as you say, the relevant scale should become N times the Planck mass, which still leaves me with the conceptually disturbing conclusion that I need to know what is 'elementary' and what isn't.<br />This is the step in Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-9676784592101140052012-04-25T11:43:00.665-04:002012-04-25T11:43:00.665-04:00Hi SGielen,
Thanks for the background... The rela...Hi SGielen,<br /><br />Thanks for the background... The relation is not Lorentz-invariant under the normal Lorentz-transformation. If you use a suitably modified transformation, it can be Lorentz-invariant. Unfortunately, this is never mentioned in Pikovski et al's paper. You can either use the normal Lorentz-transformation and be fine with macroscopic systems, or use the modified Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-37482730405832439292012-04-25T11:35:49.789-04:002012-04-25T11:35:49.789-04:00Hi Bee,
thanks for following up on this paper! I ...Hi Bee,<br /><br />thanks for following up on this paper! I only learned through your blog post that it is now in Nature physics, which leaves me rather confused.<br /><br />I seem to be credited in the acknowledgments for long and painful discussions in which I tried to discourage the first author (ordering seems important in this community ;)) from taking "modified commutators" such Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22973357.post-40821544803444263232012-04-25T00:44:59.894-04:002012-04-25T00:44:59.894-04:00Hi Jennifer,
The paper that the article you link ...Hi Jennifer,<br /><br />The paper that the article you link to refers to is, I believe, <a href="http://arxiv.org/abs/1106.1068" rel="nofollow">this one</a>. Which, however, has nothing to do with holography. The article you link to has mixed up several different things there. The GRB test is about a specific sort of Lorentz-invariance violation. Hogan claims (but doesn't show) that his Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-16672178125043601222012-04-24T13:05:33.379-04:002012-04-24T13:05:33.379-04:00Aha. That actually makes a lot of sense. It's ...Aha. That actually makes a lot of sense. It's been frustrating how a lot of these planck scale type probes (including the recent astronomical holographic test http://news.discovery.com/space/we-might-not-live-in-a-hologram-after-all-110701.html) keep coming up with null results...we need better ways to probe...Jennifer Nielsenhttps://www.blogger.com/profile/08769031507994684335noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-86835492544650459572012-04-23T19:42:00.655-04:002012-04-23T19:42:00.655-04:00You can simply watch the surface of superfluid hel...You can simply watch the surface of superfluid helium - this surface will appear rough because the space-time is grainy at the 2 mm scale already (due the CMBR noise). This graininess indeed goes to Planck scale - but I don't think, we can prove the existence of this scale with experiments at 10E+33 larger scale directly.Zephirhttps://www.blogger.com/profile/06010623752049244967noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-7145386896923547772012-04-23T15:21:58.675-04:002012-04-23T15:21:58.675-04:00Hello, Bee.
Not only Quantum Optics. Condensed Ma...Hello, Bee. <br />Not only Quantum Optics. Condensed Matter is an emergent tool to test Planck-scale effects. Look at this paper, yesterday uploaded to the arxiv: <br /><br />Bose-Einstein condesates as probes of Quantum Gravity: interesting http://arxiv.org/abs/1204.4670Anonymousnoreply@blogger.com