Saturday, October 28, 2017

No, you still cannot probe quantum gravity with quantum optics

Several people asked me to comment on a paper that is hyped by as a test of quantum gravity. I’ll make this brief.

First things first, why are you still following

Second, the paper in question is on the arXiv and is titled “Probing noncommutative theories with quantum optical experiments.” The paper is as wrong as a very similar paper was in 2012.

It is correct that noncommutative geometry plays a role in many approaches to quantum gravity and it’s not an entirely uninteresting idea. However, the variant that the authors want to test in the paper is not of the commonly discussed type. They want the effect to be relevant for the center-of-mass coordinates, so that it scales with the total mass. That assumption has no support from any approach to quantum gravity. It’s made-up. It is also mathematically highly problematic.

Third, I already spelled out in my review several years ago that this is bogus (see section 4.6) and doesn’t follow from anything. Though the academically correct phrase I used there is “should be regarded with caution.”

Fourth, note that the paper appeared on the arxiv two weeks after being accepted for publication. The authors clearly were not keen on any comment by any blogger before they had made it through peer review.

Fifth, let me mention that one of the authors of the paper, Mir Faizal, is not unknown to readers of this blog. We last heard of him when claimed that Loop Quantum Gravity violates the Holographic Principle (it doesn't). Before that, he claimed that the LHC will make contact to parallell universes (it won’t) and that black holes don’t exist (they do).

I rest my case.

And don’t forget to unfollow


  1. I began my professional career as an industrial market analyst (long time ago have had many "careers" since). Your post reminds me of something my boss in that business told me: "there is only one way for a forecast (prediction) to be right and a thousand ways to be wrong". Seems like something similar applies to the business of science. One difference, in market analysis we learn pretty quickly when we are wrong. :)

  2. "noncommutative geometry" Hund’s paradox versus the stability of chiral molecules. Before one assaults mountains, try it out with pebbles. Attend a 3D movie. Take the glasses into the bathroom, close one eye, and look into a mirror close up. What would you see if both eyes were closed?
    ...Try doing a run - diagnostic of ills.

    (Great pose! Honey badger sheathed in innocence, or Alfred Hitchcock's Pretty Poison.)

  3. Hi Sabine,

    I would like to hear your suggestions regarding physics websites (besides your delightful Backreaction, of course!). BTW I've never followed :)


  4. I shall not unfollow, sorry.
    It brings us dayly news, some of them are fake, it is a popular behaviour these tim3s.
    But I also faithfully read your blog, so I am definitely in no danger.
    I must also inform you that I preordered The Thing on Amazon.
    Mucho suxesso!

  5. I would be grateful for you to explain why you do not have high regard for phys(dot)org.. my understanding was that it provides reasonable articles on physics research that is accessible to the layman.. am I mistaken?

  6. Sudonym,

    Reporting on is incredibly shallow and error prone. They don't seem to have any fact-check at all. They rarely seem to contact anyone than the people involved in a study themselves. When I last looked at it, the condensed matter pieces were ok.

  7. Unknown,

    The best and most accurate physics news you get from Physics Today and Physics World, the membership magazines of the US American and UK Physics Societies. The tragedy is, when you're used to hype, these pages will look unbearably dull and blunt. So you have to make a choice, funky nonsense or real news? You can also look at the "synopsis" in PRL, which isn't always terrible, but I suspect you need some physics background for that.

    For more general science News, Nature News is as good as it gets, though they sometimes fall victim to trying to be too fast. ArsTechnica isn't entirely bad. They actually seem to be doing quite some footwork and mostly get things right. They don't do much physics though.

    Besides this, follow blogs... Best,


    1. Arstechnica "isn't entirely bad" but also "mostly get things right"? Can you explain?

    2. So what you're saying is that is like Fox News and Physics Today and Physics World are like the boring boring Financial Times? Given the dullness of this reality, I'd choose fake news any day

  8. For the laymen like me, stopping to read is like asking physicists to stop publishing in the journals who published this work.

  9. orezeno,

    Your comparison makes no sense.

    As I said above, it's your decision. Do you want funky nonsense or do you want to know what research is actually interesting? Sadly, I suspect that most people, like you, would opt for the funky nonsense. You realize that this desire to be entertained rather than informed is the same source that feeds the prevalence of fake news?

  10. To the unblessed (merely hanging on to coat tails of you proper explorers) it is mildly intriguing to read of those entirely consistent alternate realities that nature has not selected for us to be part of and observe.I note phys org cites in that "issue", a paper that adds to theoretical evidence against a non constant (Dirac-Brans -Dicke like) G theory. This I surmise is still up for grabs, but that such fringe theories can be debunked on the basis of not theoretically predicting stable black holes seems delightfully ironic to me.

    I get the fact checking and hocus-pocus chasing grievance though, the utter waste of human capital, the pursuit of the paper publishing chase for its own sake. We do need better sifters. Where is the glory in sifting?

  11. Hi Sabine, what do you think about Bekenstein's article Does it fall on the same category as what you discuss here? Apologies if you have discussed it in this blog earlier, I couldn't find it. thanks!

  12. I unfollowed several years ago, don't remember what the reason was, but I recall it was something that was obviously wrong even for me.

  13. Nik,

    I commented on this here. Btw, if you look at the arXiv page of a paper, check the box on the right at the bottom and click on "blog links". If I have commented on a paper, you will find the blogpost listed there.

  14. Thank you Sabine for the answer! I only now that you said the links on the arxiv page on the right hand side. How useful! I should have known it before!!

  15. Hi Sabine, I agree that I should strive to be better informed. But would I guess that this is a patently wrong paper and over the top reporting. I realized that because I follow you.

    Now I would argue that a laymen that never followed is "lesser" informed than one who follows that and your blog. Because it helps us appreciate how tread cautiously around bold claims. It remains a fact that for many like me science also remains a source of entertainment. We are not scientists. What you are missing is that as "fans" of science its not important that we forgo "entertainment" value but rather that we exhibit skepticism and fact checking and appreciation of quality of evidence (to the level we can). I apologize for rhetorically drawing parallel of calling upon physicists to boycott such journals.

  16. why do you hold onto this notion of quantum gravity when it comes out of the thickets of one of the gratest historical periods of wrong thinking. all credits to you for facing up to the inflation problem. it doesn't end there i'm sorry to say. it goes much further and deeper. But that way - alone - conceals the prizes and surprises. some which are surely nobels and much more. QG is totally sterile in its current formulation.

  17. "Third, I already spelled out in my review several years ago that this is bogus (see section 4.6) and doesn’t follow from anything. Though the academically correct phrase I used there is “should be regarded with caution.” Tee hee. Bogus. Much better.

  18. Dave,

    I don't understand the question. They cover a lot of things I regard totally uninteresting and do so in a length that is beyond my pain threshold which I why I don't follow the site. But every once in a while they produce something reasonable. I should also have mentioned Gizmodo, which is kinda similar, though with a different focus and not quite as lengthy.

  19. Actually, my impression was always that pretty much got its stories directly from the university/corporate PR blurbs for recent research. As such, I have always taken much of it with a grain of salt, whichever branch of science they are covering. I wonder whether more of your dismay should be to headline seeking university PR outfits..?

    I find the site has a nice, clean layout on desktop with lots of new stories everyday. Treat it is just as a sort of science news aggregator, with little (if anything) in the way of fact checking, and it's fine, I reckon...

  20. Sabine:

    I'm just a "mortal argentinian chemical engineer", who is very interested in my career and in sciences like Astronomy, Physics, Chemistry and Mathematics. I read frequently looking for articles in these subjects, and just recently I discovered your blog. What happens to me (and to many, I guess) is that when you start reading a paper and then it appears a lot of greek letters, subscripts, upperscripts, strange symbols, tensors, etc. etc. you can't keep on reading with just the basic mathematical skills like the ones you learn in an engineering career, so I turn to "popular" science divulgation, looking for serious articles, of course. What I didn't know is that is a bad website, giving that in most cases they link to the paper, they mention the universities where the research was done, etc. I also read and, perhaps bad websites according to your criterium. I love your blog too, though sometimes I can't follow some concepts. I promess I will pay more atention to what I read in, and thank you for your advices.

    Best regards.
    Guillermo (yes, the same Guillermo... and forgive my bad English!!)

  21. Do not unfollow, what do you follow?

    It admits there are pre-prints.

    Lisa and Bob are excellent writers. Their coverage of the big picture is outstanding and awe inspiring.

  22. Sudonym and the others who like

    It's because of people like you, who support websites that uncritically repeat nonsense stories, that the world is such a shithole.

  23. One of the reasons isn't very useful or reliable is that they indiscriminately mix actual "reporting" by their own staff with reposted articles from other sites and regurgitated press releases from university and other institutional PR departments. The only way you can really tell is by looking for an actual byline by a human being at either the top or bottom of the article. For articles without bylines, there is usually a bit of text at the bottom saying, "Provided by:". If this is followed by the name of the university or institution whose research is featured in the article, then you're looking at a press release; take it with a large grain of salt.

    Of course, if you do that in the case of the particular article Sabine is complaining about, you'll see it was written by a staffer. If you read the article, you may notice they didn't talk to anyone other than one of the authors of the original paper. Serious science journalists will usually try to get comments from people who are in the same or related fields but are not part of the same team. (You can see this in at least some Ars Technica science reporting, for example.)

    To be fair, they're trying to cover essentially all of science and technology, so it's possible their non-press-release writing is better in some areas than in others. (I don't follow them, so I don't know.)

  24. Re Bee...Social Intent is the triumph of ideas over facts. Progressive mentation - Snowflake life, free money, immunity to law, perversity of love, rejection of nationality, denial of objective knowledge - kills civilization.

    Reality is not a peer note: pneumonic plague in southeastern Africa, 860,000 Yemenis with cholera. "Dark Matter Day" is not harmless if wrong. Earth is a lost cause. All one can do is leave, with nowhere to go and no way to get there. Theory is not benign. Centralized macroeconomics says so.

  25. Peter,

    Exactly. I am pretty sure that if you ask them how that is that they don't do more footwork it's because they don't have the staff which is because they have no money. So in the end the problem is people who expect that others work for them for nothing.

  26. Uncle Al,

    This seems to be a rare instance in which I agree with you.

  27. Or, Sabine,

    A rare instance when, inferentially, at least, parts of an U.A. post might be broadly comprehensible by earth residents...

  28. Give me options and I will listen. As though standford library is bad? It is written for a high school reading level.

    It's going to be hit or miss. You cannot fail at interpretation or the manipulation of concepts. You can prove, in a given discovered structure, a contradiction. You can attempt to replicate results. You can fail to calibrate and instrument.

  29. Come on Bee, get a grip.

    Whether or not quantum gravity can be probed with quantum optics (or any other wrongheaded speculation on where physics goes next) has next to nothing with the "shithole" status of the world.

    The most obvious thing that does run the risk of creating a real "shithole" globally is the disgraceful 30 odd year campaign waged by vested interests in fossil fuels and your generic culture warriors to discredit climate science. Now that is serious.

    On that front, I don't think has ever pushed anything other than mainstream climate science. Those media outlets that do (hello, Murdoch press) are the ones that deserve real attack. Careless science reporting of fundamental physics may be annoying, but it doesn't involve malice and actual long term harm, and as such it's over the top to be decrying not just, but the people who read it.

  30. Steve,

    Too many of us blame "powerful players" when really the problem is our collective idiocy. Humans did not evolve to comprehend consequences of their joined actions giving rise to emergent trends among billions of us. If you expect free news, they'll be of no value. If you share and support low-quality reporting because you want free entertainment, you're part of the problem.

    I agree of course that when it comes to quantum gravity it is hardly relevant, but the same trend in other areas is hugely worrisome.

  31. Dear Dr B
    "Too many of us blame "powerful players" when really the problem is our collective idiocy."

    I am afraid this is a remark in the line of "half of the people are below average". We cannot fault people for being less able than the best, being playing the piano, sports, science, or politics. In science and politics, the only thing that works is trying to take them by the hand and lead them along. Which you are already doing very fine.

  32. Rob,

    The remark says that on the average all of us are average and we better take this into account when we make decisions.

  33. "really the problem is our collective idiocy"

    Yes. One of the many consequences is that many of us will follow people like Hitler, Stalin, or Trump without questioning our assumptions. By definition, the average IQ is 100, and in my experience 100 is not smart. That was the sense I got from your previous comment about and I agree with it, as an empirical fact.

    I wish I knew what to do about it. People who can't analyse complex issues can only be indoctrinated, and the wrong people are the experts in indoctrination. Technology could be helpful, but only if used wisely, which we probably won't do.

    For example, consider all the time and effort being spent on developing self-driving cars. Wouldn't it be more beneficial to apply those resources to expanding and improving public transportation? As I walk a few miles to a market, in about 15 minutes about 100 cars go by me (in both directions), most with a single person inside. This is not a sustainable model, it seems to me, and there seems to be a lot of that going on.

  34. Well, I do subscribe to Science as well as read, so I hope that gives me a "pass"! :0

  35. If you do not fact check then you are accepting things on faith.

    I don't care how scientific you think you are, if you do that, I will consider you a religious person.

    That's ok in my book. I am one myself.

    The pretense that you are not, because somehow a scientist acting like the Wizard of Oz is more believable than a priest, makes me roll my eyes.

  36. JimV,

    Intelligence is not a protection against social and cognitive biases. In fact, that too many scientist think it is causes a lot of problems. Just because a lot of people believe (share, talk about) a story doesn't mean it's correct.

  37. @JimV

    What you related is the Tragedy of the Commons, a very long-standing problem, of which I'm guilty of myself. I drive a car to my market.

    However, your comment about the effort about developing self-driving cars seems to assume that someone is in charge of developing a Master Plan. Hopefully you know that isn't true? At least in the US, there is no Master Plan with respect to sustainability, and in fact, sustainability itself is not a universal goal?

    My favorite video game, Alpha Centauri, circa before the turn of the century, had a character say this quote:

    CEO Nwabudike Morgan "The Ethics of Greed"
    Resources exist to be consumed. And consumed they will be, if not by this generation then by some future. By what right does this forgotten future seek to deny us our birthright? None I say! Let us take what is ours, chew and eat our fill.

    It made me laugh when I first heard it. But I've since learned that not only is it the mainstream opinion, I'm guilty of it myself by simply posting here, on my computer, in my electric-powered house.

  38. “It's because of people like you, who support websites that uncritically repeat nonsense stories, that the world is such a shithole.” Ouch! All this time I thought it was a lack of empathy. Granted, nothing should be read uncritically. How much of what we think is true today will future generations understand as nonsense? We have many blessings now, thanks to science, that our ancestors would look upon with wonder and amazement. One of life’s great mysteries is the lack of a correlation between human intelligence and wisdom. Many great minds have done horrible things. We are (probably all of us) still ethical infants.

  39. "Intelligence is not a protection against social and cognitive biases."

    I agree, not an absolute protection, but I think that intelligence can be used to try to overcome those biases. Otherwise I would be a semi-racist, Evangelical Christian who voted Republican like the rest of my family. I know some stories about scientists who refused to abandon their theories in the face of evidence, but more stories of those who did.

    "...your comment about the effort about developing self-driving cars seems to assume that someone is in charge of developing a Master Plan"

    Not exactly. My own master plan is never to own a personal car, and to support public transportation (buses and trains). I am proof of concept - the proof that it can be done, although it is harder now than when I was young and one could take trolley cars (with transfers) from central New York state to Massachusetts. We are all in charge of our own master plans, to extent that we have the resources to put them into effect.

    In the previous car-counting anecdote I wanted to write ten minutes, but was afraid my memory might be exaggerating so I wrote 15. So yesterday I repeated the experiment, and counted 100 cars in 5 minutes, on the same two-lane, local highway, again mostly with one person per car (at 2:30 PM; there would have been fewer around 10 AM and more around 8 AM and 5 PM; much fewer before 7 AM and after 7 PM).

    This is one example of a bigger problem: we are consuming our world's resources much faster than they can be renewed and in an inequitable and often unnecessary way. I think the evidence is clear on this, and it cannot go on forever. That we do not have any societal Master Plans to address this reflects badly on our average intelligence and/or social and cognitive biases.

  40. "....that the LHC will make contact to parallel universes (it won't)..". I confess that I was electrified when I first read about the concept of large extra dimensions as delineated in the 1998 ADD paper, and later variants such as the Randall/Sundrum models. So it's a great disappointment that such concepts appear to have lost their viability.

  41. This comment has been removed by the author.

  42. @JimV

    Kudos to you, and I mean that sincerely. It's people like you who will insure our descendants have the same standard of living we enjoy.

    The energy in fossil fuels is huge, and easily tapped. If we fail, I'm not sure if our descendants can achieve what we have without it, especially if we've taken the low hanging fruit.

    On the other hand, I'm beginning to doubt if we are happier than hunter/gatherers.

  43. Nature seems to express a language that can be braced as 'radical introvert-ism' due to its shy and unrevealing adamancy and stubbornness. Well, seems to be a veiled groom, waiting us to dive into philosophy of oneness where it can 'ruin' our souls to a form and language understood by nature. This seems a self proclaimed statement! I think post-modernity allows me to apprehend it as what Mr Heisenberg long felt, probing a reality and information contained in matter at its really basic level, may be a field or some string or some divine liquor, disturbs the instantaneous state we had been in search of, scattering it in a secret black box covered by coarse veil. When Einstein braced a paper " Can Quantum Mechanical Description of Physical reality be considered complete" or Socrates plausible statement of "I know nothing and we are in search", but these minds seem vague in Sabinaic wonderland. These were the words when I met a week ago with Mr Faizal with a smiling yet undistinguished face. The threads of space time being woven by invisible divinity. seems to be gorgeous that physically manifested at its basic level as gravity, hence is an inseparable percept, that is said to be weakest of all but whose loud silence is the dice once played by God! We made a first attempt to make an imprint to see how to approach this shy nature, of which I am sure is a Woman like Sabina, Faizal blasted in laughter and said " We are not into the veiled black sphere of reality, Suscind sat outside his hologram to dictate things, Maldecena correspondence made him to scratch the surface and see how nature is, what is that I want to probe inside it into the ruining singularities of black giant and sabina cares so much for me"

  44. With the Planck scale being 17 orders of magnitude higher in energy than the Electroweak scale, it would seem hopelessly beyond our civilization's, or any civilization's ability, elsewhere in the cosmos, to exploit the quantum gravity domain for technological purposes - in the sense of creating localized gravity-like fields, or modifying inertia. This, of course, doesn't rule out detecting Planck scale phenomena at much lower energy scales by some clever experimental configuration.

    However, from my own belief system, I do hold out a glimmer of hope that humanity will someday be in possession of the technological wherewithal to create artificial gravity. Now I realize this is not something that should be mentioned on a scientific blog, but if one is to take the more unimpeachable reports of anomalous objects cavorting in our atmosphere at face value, it would appear that 'someone', somewhere has already achieved such technology. This, presumably, would be impossible unless there is new physics far below the Planck scale that has not yet been discovered here on Earth. Again, I emphasize, that this assessment is a function of one's own personal belief system, and is obviously not going to be shared by everyone.


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