Monday, May 12, 2014

Physics Overflow is live

Off-topic, breaking news: Jester believes that there are rumors suggesting that Planck refutes BICEP2 and many experimenters, including those in the BICEP Collaboration, are admitting that the B-modes came from the dust. Clement Pryke of BICEP refutes Adam's rumors about the planned retraction in the Science Magazine while he admits that they don't quite know the right interpretation of a key Planck map. I won't say what I guess about these claims.
Some of you may know Physics Stack Exchange where people may ask and answer physics-related questions. But you may often have the feeling that no one is trying to keep the quality of the traffic sufficiently high. Thanks to Dilaton, Dimension10 etc., a new very promising competition has emerged. It's called Physics Overflow:
PhysicsOverflow.ORG (click here and try!)
You may see that the name was inspired by MathOverflow.NET.

Especially if you're a student or a professional physicist who sometimes feels that he or she wants to ask a question or train his or her brain by answering a question from someone else, you should create an account over there. You may be pleasantly surprised by the professional flavor of the new website and if it is so, you may want to encourage your colleagues to join, too.

Much of the useful stuff – but not all the stuff – from the Physics Stack Exchange has been helpfully reproduced on Physics Overflow. The quantity and quality of the traffic has looked encouraging so far. Give it a try!

I hope that the hard-working people behind the new website will answer your questions in the comment section of this blog post if you happen to have some questions. Incidentally, the TRF discussion on old and new theoretical physics forums started in August 2013 has over 750 comments right now but be sure that the folks had to do much more work outside similar discussion threads!

Thanks for the work.


  1. Thanks so very much Lumo for this :-) !

  2. kashyap vasavadaMay 12, 2014, 5:18:00 PM

    Congratulations and thanks Dilaton and Dimension10 for this website. I will look at it and try to learn from it.

  3. Great work Dilaton! I'll sign up straight away..

  4. Re Off-topic: I dont want the nice BICEP2 results to decay to dust ... :-/

  5. Ned wright who works on the microwave background is not convinced of bicept2 in his news of the universe column.

    The bicept2 graph does not look good at all.
    Seems too much stats is needed to squize the result out.

    I thonk we have to wait for tricept3 with triple frequencies instead of just one.

  6. Oh no, a Jester conspiracy theory. If the sky research did get censored due to politics, don't forget that politics swings many ways. So a patch of sky "masked to hide proof A" could also be the patch "masked to delay confirmation of proof B". Politics is a business of patience and deceptively traded interests. Physics is a science of patience and deceptively traded interests. Business dominates the world, so I call bs.

  7. Shared on my blog, congratulations and good luck for developers!

  8. I just love to see likable and also in some ways sincerely truth-tracking people supporting, clicking with, or inspiring each other!!

  9. This new website proves that you Dilaton is not just a 'pretty' (by me liked) WWW-personality but a worthwhile weaver with get-up-and-go!

  10. The site looks good now, thanks to this blog post among other things :-)))

    For getting PhysicsOverflow up and running, the great work of our system developer Polarkernel and the work of Dimension10, who seems to be very talented for everything, and does many different things 24/day ;-) on PhysicsOverflow, was and still is crucial.

  11. The Jester rumor sounds a lot like the "faulty cables" case, remember that one? A lot's (and I mean a lot's) of politics involved again here too. After all the political crap seen each time when some (otherwise perfectly sane group of physicists) even touches on a paradigm topic, I'm not even sure I like science any more. For it all does seem to boil down to which of the opposing sides has more muscle to flex (or if you prefer it in plain English: the moneys). And who can beat the particle physics gang money-wise? Only the Chinese Army, my friends!

  12. Thanks a lot Lubos, for this post : )

  13. The loose cable was a fact, this is a speculation. Don't you see the difference? I haven't understood what you don';t like about science except for some propaganda that you deliberately added on top of science.

  14. Congrats Dilaton et al.

    I admire your patience and determination to launch such forum.

  15. The guy from BICEP2 shouldn't have gone to Linde's house to announce the results if they weren't 99 to 100% certain.

  16. Dear Giotis, they were formally at least 99.9999999% certain, that's what the 6-7 sigma confidence level means, and even when some possible "qualitatively different errors" are considered as possibilities, their certainty is still vastly higher than 99%.

  17. I thought was obvious: I hate funding disparity - the kinds of money SUSY gets tops what all others get, combined! As far as the "faulty cables" case is concerned: now after BICEP2 it doesn't seem entirely impossible that OPERA was actually correct in the sense that they first observed a neutrino jump between overlapping universes in a multiverse setup! So can you bet your money now that some secret service wasn't involved in fault play or something? Too much money is at stake, sonny. With this latest Jester tumor-rumor: where there's smoke...

  18. Concerning your obvious dislike of particle physics or HEP this negative attitude is shared by the US governement pulling itself out of the business.

    It is really beyond me you such ... people as you begrudge this field any cent it gets and misbehave as if they personally could not buy enough food the next day, if the governement supports this field of science...

    This negative and destructive attitude, widespread among most laymen, made me stop reading comments in unmoderated blogs and below popular (and sometimes even not so popular) news article about fundamental physics topics already years ago.

  19. Are you aware that one airplane carrier costs as much as LHC? And it is liable to end in the bottom of the ocean in case of war. And there are many airplane carriers. People should stop bloviating about the expense of basic research.

    Are you aware that the web on which we are now discussing is a spin off from very basic research? What is the value of the Web for society?

    Now for the problem at hand with BICEO2. They used a figure from Planck to model dust in their region of the sky. This region was chosen specifically because it has small background .IYet it may be they have underestimated the errors for this calculation, and we have to wait and see what BICEP3 will show and what Planck and the other experiments will show in the near future. This does not invalidate the importance of the study which brought to our attention the way to discover gravitational waves and the effects of quantization of gravity.

  20. I didn’t like this theatrical entrance in Linde’s house right from the beginning. They put him in an awkward position by forcing strong emotions. It was not fair. If the results turn out to be wrong Turok will watch the video again and again, eating popcorn and laughing his ass off.

    But let’s hope the results are solid.

  21. It wasn't obvious to me because I really can't imagine how someone may possibly be such an insane hardcore communist that he would like "parity" in funding of totally different pieces of science.

    SUSY is vastly more important and motivated than any other single "program" of beyond-the-Standard-Model particle physics phenomenology, so this is obviously reflected in the number of citations, papers, and grants. How it could not be? What would it be for totally different programs to enjoy "parity"? Could I triple my funding just by splitting a program to three new programs? What you write about the parity makes absolutely no sense.

    For years, I would live in smoke and smog that wasn't really caused by fire so I know that your stereotype that there must fire in every smoke is just idiocy, a way to make sure that every libel sticks. I won't overwhelm you with quotes but I despise people who automatically at least partially believe everything they hear. They're the so-called gullible morons. Please take it personally.

  22. Sorry, Giotis, but your comment is totally illogical and stupid.

    Linde's fame doesn't really depend on a large, observable tensor-to-scalar ratio. Even if BICEP2 turned out to be wrong, Linde would still remain a 1,000 times better and more respected physicist tham Turok and his papers would still be used.

  23. Darn why only is Diskus supporting such trolling by removing the downvote feature? On Sean Carrolls blog such trolls can be downvoted to oblivion, and if the negative score surpasses a certain value, the comment gets collapsed. Why does Discus not do the same? Do they have a place for feature requests ...?

  24. @Dilaton: In this particular case, I agree with you and Luboš that AtItAgain was trolling unbelievably. But in
    general, power of wiping out comment by down voting is dangerous! On Sean’s blog it is pretty much impossible to
    make comments disagreeing with Sean. They are down voted quickly by his
    followers! I have written a strong comment on Sean’s blog. “This power of voting out a comment, with
    which one does not agree, goes completely against the spirit of science. In a
    scientific discussion, all views, whether you agree with or not, should be
    permitted. In published papers, at least, you know about the qualifications of
    the critics. Here you have no idea of who is voting against you! I visit many other physics blogs and on one of
    them even had a guest blog published. This is the only blog with this outrageous system.” So in my opinion that is also not a good system. Surprisingly
    this comment has stayed on (+4, -3) for 3.5 days!!

  25. Parity is everywhere around us, an everyday fact of life. No one idea should be valued above and more than any other idea just because some or even majority (democracy in science? If you advocate that then you're the moron here) think the outcome will be more important. How do you quantify importance here? By quantity of papers as you say? Then you're not just a moron, you're an outright imbecile, given that your wiki page (that you wrote yourself) lists less than a dozen papers. So according to your own standard, you're a moron really. But I know you're not because I keep reading you and love your line of thinking. Except for sometimes when you piss people off on purpose like that coffee shop guy in Seinfeld. About US Government agreeing with my view and cutting the funds on SUSY, here's a sweetener for you: they listened to me and cut (I mean reeeeeal cut) the funding for NASA over past 6 years. I won't explain myself to someone like you, I'm here just to relax. But conspiracy I was mentioning earlier on OPERA is as real as it gets. You can take it from the guy who prides himself in cutting science budgets for more than 900% across the board over the past decade or so. This is the world of conspiracies my friend, 3/4 of grants you think are given on merit are given at a local bar under the table with 10-20% bribe fee to the grant issuing official. Want more? Some other time, I'm off to a budget meeting now where I get to influence whether we sink SUSY now, or we leave it for next Yankees game.

  26. I had not been aware of the video's existence and just watched it. I was amazed that millions of people wanted to watch this announcement, which is good, for spreading basic science. It is also a good video of the measured and I might say realistic stance of professor 1.51 he expresses his skepticism even, "what if we are tricked, our belief ..." .

    I do not think that there is anything to be distanced from in this video, anything. It is a eureka moment shared. If doubts come in and one has to gather the bath water and measure and measure again, that is fine.

    But it is a good moment joining experimentalists to theoriests, because if there were not this future objective moment point, a eureka expectation, there would be no experiments.

  27. God bluff, sounds very impressive LOL :-D !

    On the other side, uninformed anti-science trolls as you having an impact on the fundings of physics topics they have no clue about, would perfectly explain the dawn of a new period of Dark Middle Ages in the US, as it is observed to have begun years ago.

    Happily there are other parts on the globe, where countries are emerging out of darker or difficult periods, and they will be proud and happy in helping the human civility making progress in advancing its knowledge and developping new technologies.

    So in the end and from a global point of view, it does not really matter that the US governement is pushing that country into a new Dark Age of ignorance, even though it is a pitty for the good nice and bright people there.

  28. What a disgusting troll. I didn't read his comments till just now; but this is really terrible, ugh. I wish I could downvote it a hundred... AARGH!!!


    I have no idea what DiSqUs thinks is the purpose of downvotes any longer if they stop showing them at all. This is starting to become a common norm; not showing downvotes; it will not be long before SE starts doing this (they've done this for comments already, they don't even have an option to downvote them).

    Dear Disqus team, we want our downvotes back! At least give blog owners the option to enable them; I'm sure Lubos won't hesitate one bit before turning downvotes back on!


    Please disqus, no-downvotes is for social media, not for places where people can be frank and communities can destroy and behead trolls. What? Is that antisocial? I told you we're not social media!

  29. Hi kashyap,

    I see no harm in giving the communities living on different blogs for example the possibility to build their own standards and identity by deciding themself what behavior and what kind of comments they appreciate. This is not the real world, people who do not agree with the spirit or athmoshere on a certain blog can just move on and go somewhere else ...

    I dont like the attitude, obviously now adopted by Discus too, that whatever anybody does or says has to be tolerated and is ok and that communities are not allowed to develop their individual standards and culture.

    Of course, the owner of a site has the right to moderate it as he pleases anyway (the Trollking legitimately has the right to censor out and delete whatever comments that do not agree with him ...).

    So I really see no problem with allowing a community to downvote and even make collapse comments that are not up to their standard...


  30. By the way, I'd like to point out that PolarKernel has made great progress with the reviews section, which is summarised here:

  31. Hi Lubos, I wonder if you could answer this question?

  32. Oh yes Lumo, please ... :-)

  33. Hi Lumo, I know that you are busy with the Higgs contest (want to see you get the bucks!) ;-)
    But maybe you could afford a short comment to this ...?


  34. Dear Dilaton, I am doing mostly other things than the contest.

    I can't usefully answer the question because for AdS/CFT, the answer seems to be empty because there's only one decoupling limit, and I remain unconvinced whether there is any controllable non-AdS/non-CFT which is the other aspect of the first question.

    The completely second question asks about way too vague configurations. Which "these solutions" are or aren't unstable? The OP hasn't written down any solutions. Of course that just a spherical brane in flat space with anything else is unstable - it shrinks and collapses by the attractive gravitational plus electric force. In various combinations, the branes may be stabilized so that one gets stable and static solutions but there are infinitely many of them (in diverse classes) - and infinitely many of them don't exist or aren't solutions. So I don't really see a well-defined enough question that I could meaningfully answer.

  35. Hi Lubosh Motl
    I beg your pardon, that is not on. Please comment on the page of Wikipedia
    about the collapse of the photon, the three-dimensional space, and about the Heisenberg uncertainty principle at the Planck scale.
    Do you agree with this?
    Answer here or send an email to the address:


  36. These unusual cousins of the uncertainty principle are always less fundamental and more speculative. One may carefully analyze what's in them to see whether there is a solid argument or not. Mostly, the answer is No.

    Instead of "delta R times delta X greater than Planck area", the relevant inequalities are linked to holography - which is also of the form "area is greater than the Planck area" but which exact area is at the beginning of the sentence is problematic and one must be careful.

    It's a mixed baggage, I would surely not endorse every detail of the page and the naive treatment of those things, but at the same time, the Planck length does mean similar things. Sorry, i can't just publish a commentary on any long page on Wikipedia, especially if you don't even pay me a minimum salary for that.

  37. What happend to the Uduality blog ...?!

    When I click

    the expected page shows up for about 2s, but then I get redirected to an an advertisement page ... This is annoying, how can I prevent the redirection?

  38. Either it was hacked or the owner of the blog is earning from those ads and it's a good method!? ;-)

    You may look at the mobile version of that blog which doesn't redirect

  39. Hm, that is quite surprising; I thought blogger wouldn't allow such (for users malicious) scripts to be posted by administrators? I would by surprised if it was easy enough to hack a blogspot blog...

  40. Just click the stop button or press "esc" during those 2s. I am also very surprised by this; I just learned about that blog a few days ago : (

  41. What I meant by hacking is that someone found his Google account password which gave him access to all these things including the blogger and its templates.

  42. The complete blogs are really inconceivable and definitely everyone will share this information.lexington law

  43. Here's David Mermin on why Qbism is not the Copenhagen interpretation and what John Bell might have thought of it:

  44. I agree with most of the paper but he's wrong about the primary claim. QBism *is* just a fancy new word describing the very same thing that Bohr, Heisenberg, and others in Copenhagen meant to define the foundations of quantum mechanics.

  45. "To state that my understanding of the world rests on my experi
    ence is not to say that
    my world exists only within my head, as recent popularizatio
    ns of QBism have wrongly
    asserted." Everything that i read about QBism until now imply that space time don't exit independent of mind but apparently mermin believe something else , above sentence was disturbing for me , i don't know how he interpret QBism but whatever his interpretation is for me it is not QBism .

  46. OK, there is a lot of room for personal idiosyncracies concerning the wording etc.

    But I think it is equally fair to say that QBism (or quantum mechanics or Copenhagen interpretation, these things are really the same) *does* deal with properties of an external world - it just doesn't allow the maximum knowledge about this external world to be objective and unique.

  47. Lubos - For the most part I agree. The paper has little real substance and, like most philosophy of science, what is has to say is either trivially true or profoundly false. I still maintain that there is more to QBism than what you have taken from it (and with which I agree), but hope we can agree not to rehash this argument.

  48. I don't believe there is a external world outside our mind that contain information about reality that we experience .i think holographic principle and quantum correlations can explain what we experience as reality.

  49. I just posted a long blog post about Mermin's new paper.

    When you say something else is in QBism, is that bonus thing good, or bad?

  50. Hi, holography may subtract one dimension but it still allows to divide the world into pieces, at least in the remaining spatial dimensions, and perhaps even in the holographic one.

    When I or Landau-Lifshitz etc. say that there is an external world, the claim doesn't mean that this world has objective properties that everyone has to exactly agree about, or that it follows classical dynamical laws.

    Instead, it just means that all the question about the state or properties of things may be summarized as knowledge about observables that are in general independent of observables describing the brain. So a good theory must agree with the fact that the brain and external-world degrees of freedom are a priori independent. This is a different assumption than anything about objectivity of the external world or determinism.

  51. "interminable quotes from
    the philosophical ramblings of William James"

    Hey! I like William James!

  52. Subjective refers to what we experience privately, inside our heads. When a bunch of scientists are sitting in a room watching the double slit experiment unfold (while firing one particle at a time) their subjective experiences of what is happening on the counter (the pattern of events) agree. That is what we mean by objective, subjective agreement.

    I'm obviously a layman and an idiot, but what is subjective about the results of quantum mechanical experiments?

  53. So do I! James was very much a man of his time (e.g. - Peirce made more original and lasting contributions) and looking to him for insight into a physical theory developed after his death is just silly.

  54. Lubos - Sorry for the late reply. I just noticed your comment.
    Please be assured that I view that 'bonus thing' as bad.

  55. In the '... what John Bell ...' article referenced by RAF III, Mermin states: "My talk is intended primarily for the growing minority of philosophically minded physicists who, far from rejecting QBism, are starting to maintain that there is nothing very new in it." and in the footnote he states, with his usual dry twist (4): "I count this as progress. The four stages of acceptance of a radical new idea are: (1) It’s nonsense; (2) It’s well known; (3) It’s trivial; (4) I thought of it first. I’m encouraged to find that stage (2) is now well underway."