Message in a Wobble: Black Holes Send Memos in Light


Imagine a spinning black hole so colossal and so powerful that it kicks photons, the basic units of light, and sends them careening thousands of light years through space. Some of the photons make it to Earth. Scientists are announcing in the journal Nature Physics today that those well-traveled photons still carry the signature of that colossal jolt, as a distortion in the way they move. The disruption is like a long-distance missive from the black hole itself, containing information about its size and the speed of its spin.

The researchers say the jostled photons are key to unraveling the theory that predicts black holes in the first place.

“It is rare in general-relativity research that a new phenomenon is discovered that allows us to test the theory further,” says Martin Bojowald, a Penn State physics professor and author of a News & Views article that accompanies the study.

Black holes are so gravitationally powerful that they distort nearby matter and even space and time. Called framedragging, the phenomenon can be detected by sensitive gyroscopes on satellites, Bojowald notes.

Lead study author Fabrizio Tamburini, an astronomer at the University of Padova (Padua) in Italy, and his colleagues have calculated that rotating spacetime can impart to light an intrinsic form of orbital angular momentum distinct from its spin. The authors suggest visualizing this as non-planar wavefronts of this twisted light like a cylindrical spiral staircase, centered around the light beam.

“The intensity pattern of twisted light transverse to the beam shows a dark spot in the middle — where no one would walk on the staircase — surrounded by concentric circles,” they write. “The twisting of a pure [orbital angular momentum] mode can be seen in interference patterns.” They say researchers need between 10,000 and 100,000 photons to piece a black hole’s story together.

And telescopes need some kind of 3D (or holographic) vision in order to see the corkscrews in the light waves they receive, Bojowald said: “If a telescope can zoom in sufficiently closely, one can be sure that all 10,000-100,000 photons come from the accretion disk rather than from other stars farther away. So the magnification of the telescope will be a crucial factor.”

He believes, based on a rough calculation, that “a star like the sun as far away as the center of the Milky Way would have to be observed for less than a year. So it is not going to be a direct image, but one would not have to wait very long.”

Study co-author Bo Thidé, a professor and program director at the Swedish Institute of Space Physics, said a year may be conservative, even in the case of a small rotation and a need for up to 100,000 photons.

“But who knows,” he said. “We will know more after we have made further detailed modelling – and observations, of course.  At this time we emphasize the discovery of a
new general relativity phenomenon that allows us to make observations, leaving precise quantitative predictions aside.”

Links: Nature Physics

33 Replies to “Message in a Wobble: Black Holes Send Memos in Light”

  1. It must be a powerful black hole indeed: it ate the title!

    AFAIU wavefront topology isn’t only useful in astronomy, but IIRC the same staircase formation described is being used in microscopes to improve resolution without unduly heating the lighted object at the center.

    It has been interesting having Fabrizio (several times) and his group visiting Ångström @ Uppsala University, especially the anechoic chamber looking at OAM modes with Bo, during the time I’ve been there recently. Informative lectures, for one, especially for me who knows next to nothing about antennas. Good to see that the work has been useful!

  2. This is an example of parallel translation of a vector in spacetime. Here the field vectors of the electromagnetic wave are parallel translated in the curved spacetime. This frame dragging results in the rotation of the field vectors, where they twist around in the same way light cones are twisted.


  3. I’d rather imagine an electric current seeking charge equalization from the symmetry breaking charge separation created just post Big Bang, and said current powering the effects at the galactic central region consisting of a charge condensation volume in the plasmatic central region storage area, the toroidal equatorial charge disc attracting the central polar magnetic field expulsions of ions and sending them back to the central plasmatic condensation storage volume that is somewhat magnetically contained, via the galactic spiral arms that act as the vector for charge transmission pathways to the central core, and said electrical effects supplying all the ‘missing energy’ and ‘missing mass’ from the gravity-only galactic models; making ‘dark energy’ and ‘dark matter’ unnecessary and unneeded to account for observed galactic rotation properties and characteristics.

    1. Eh? One long sentence. Haven’t you heard of punctuation?

      Black holes are a consequent of gravitation not electric currents. As far as I know, black holes have nothing to do with ‘dark energy’ or ‘dark matter.”

      We have already proven the notion of Bostock in 1958 that “…galactic spiral arms that act as the vector for charge transmission pathways to the central core.” is now completely wrong and many relevant astrophysical papers with many citations show this to be true. (See Jean Tates great UT article; “Magnetic Fields in Spiral Galaxies – Explained at Last?” of 3rd April 2010;–-explained-at-last/ See my sixth comment, with reference sources.)

      As for the rest of this, sorry, it is just quite wrong and nonsensical.

      1. That is the purest and most absolute form of jibberish. Lars’ effort here might surpass the balderdash written by the other guy on “rings of black holes.”


  4. wow; that wins the longest sentence of the month award lars!

    what is this “plasmatic central region storage area” of which you write?

    1. Pay it no mind – it was just a bunch of sciency-sounding words stuck together that make no physical sense in a (ridiculously long) sentence.

      1. he certainly has some unconventional views of the galactic structure. he’d be better to employ a less manic writing style in order to help the reader more clearly understand whatever it is that he is trying to explain.

  5. “I’d rather imagine….” – lars February 13, 2011 at 10:41 pm

    Thank you, lars. And I’d rather imagine I hadn’t read that. I’m glad I was not the only one who had scratched their head at the comment.

  6. To bad it’s taking so long to get the JWT up in the air. With it one could look at a an early population of AGN’s (Active Galactic Nuclei) with the hope of seeing some kind of nonrandom spin orientation in space/time. The hope is to tease out information on any preferences inflation might have had with respect to space/time. A pattern. Working back to the point in time when a “specific bundle of energy” held together by some force lost its symmetry and went very quickly from a potential to kinetic energy state. Within its event horizon (if it had one) it was already kinetic? What evidence we can to pin down for the state of the Cosmos before the Big Bang and the formation of our Universe? Using the MBR along with the rotation of the early AGN’s we might get a closer glimpse at the loss of symmetry event itself and as importantly, any directional energy preferences during inflation. Our own galactic orientation is problematic. So…. what can we know about the pre Big Bang conditions? One: Some attractive force was involved. Two: For some reason that force lost control (symmetry). Three: A change from potential to kinetic energy was involved. Four: Event Progression (Time) was already in place. Presuming a infinite state of cosmic reality. Five: Whatever caused the attractive force to lose containment of all this potential energy, might have left it’s signature in both the MBR and in early galactic spin orientation (before the first galactic collisions took place). At the least it might shine some light on inflation….. Just some thoughts.


  7. Hello, everyone!

    I’m new to posting here on UT, but definitely not new to the website, as I’ve been coming here for the past 4 years to check on exciting new news in the universe.

    I’ve never posted before now, but I’m wondering where all this PC/EU stuff came from, because I don’t ever remember seeing it in the comments until recently (past few months).

    One can only hope that they will decide their efforts are futile on a website where people actually understand the science and they’ll quit annoying us with all the nonsense.

    BTW, thanks to UT for being such a great website. Thanks guys!

    1. @Jim

      “….I’m wondering where all this PC/EU stuff came from, because I don’t ever remember seeing it in the comments until recently (past few months).”

      Discussion of PC/EU at UT seems to ebb and flow, over the past several years (like tide goes in/ tide goes out……you can’t explain it!) 😀

      A google search for “universe today anaconda” found this 88-post classic from 2009:

      Unfortunately, there are many other examples (but, I agree, Universe Today IS a great website).

      1. Ahh – the bad ol’ days eh Jon?! I still remember the flow of that particular thread to this day.

        Yes Jim – you must have missed the crescendo of the EU and other alternate reality quackery around 2008/2009. If you check the comments from then, almost every single article was followed by a comment stream that was derailed by some loon espousing his/her pet theory (and I use the work not in the scientific sense but more in the sense that the general public use it – i.e. some vague personal feeling about what they think has to be the case.

        It got so bad that UT had to put a new comments policy in place, specifically banning attempts to continually overtly promote or ‘sell’ against-the-mainstream or otherwise debunked ideas – it was completely drowning any semblance of actual discussion of the science of the articles, and almost killed the site completely in my opinion. Most of the loons eventually left with the new comments policy, but occasionally you’ll still see veterans of this comment war break out the snide remarks or even fully go to town on someone who brings this stuff up again. It seems to be having a bit of a resurgence…

      2. With respect to the tide going in and out

        this is Bill O’Reilly’s finest hour for Faux News. Some people seem to need any chain of explanation to end with supernaturalism.

        It is important to push the EU/PC guys back. It is the same with creationism and other faux sciences. Otherwise this stuff can grow like a weed and infect everything. The best way to do this is to illustrate how it is jibberish.


      3. Yeah, I think this is a good illustration of why good science and the understanding of it is important. Bill ‘O Reily is clearly not a scientist and shows his ignorance in this clip. I can’t even really get into how his logic is wrong because he clearly doesn’t even understand what he’s arguing against.

        Funnily enough, on The Colbert Report, shortly after the original clip aired on television that this clip is a commentary on, Neil deGrasse Tyson explained everything that ‘O Reily said you can’t explain in the original clip, in less than a minute if I recall correctly. If I find the link I’ll post it.

      4. Some people do honestly believe that the only good science is one that validates their faith. They forget true science has exacting rules and methodologies to ensure validation of observed results and use this to find the explanation of its underlying theory. It is not just some random decision as some point of view or opinion. They also forget that their god also likely created the world as a mystery to be solved; leaving all humankind the important traits of curiosity and learning.
        IMO, the EU/PC at its hearts wants an alternative to the current cosmology lies in fear that its final solution will eliminate the need for God in the creation of the universe. (Hence them wanting the universe to be infinite.) Having some alternative theory, they feel, this might delay this inevitable conclusion. This explains the utter desperation to eliminate the Big Bang, black holes, quantum mechanics, etc. (and sometimes even gravity itself.).

        In the end science is never based nor founded on the tenets of faith. Using science as a crutch to support any dogma will always be doomed to complete failure. They, are basically in fact, the proverbial ‘chalk and cheese.’ Science, after all, lies in the observable world of substance and form, and not in the hidden veil of untestable supernaturalism.

      5. I am not aware of a religious agenda behind EU/PC stuff. I do get a rather conservative tone to their agenda. It is strange that people can be so passionate about something which is so clearly flawed.


    2. Well jim, it is basically every topic that has these words in it: “Big bang”, “Black hole” and “Plasma”. When you see any of these words then you instantly know that some PC/EU mantra is coming.

      1. until reading the link above, i had no idea what EU theory was. after a little research of its history and debunkment, i find it interesting that it inspires such debate here on this website. if it’s so obviously untrue, why is it so passionately attacked instead of being ignored? are you people worried that these EU posters (probably only one or two name changers) will “recruit” followers and change the course of mainstream theory? with this theory in its current form there is almost no chance of that happening.

      2. You see, EU/PC is just one form of pseudoscience. Some others are the Anti-Vax-Movement or Creationists (for more information on both check the BadAstronomy blog of Phil Plait).
        Some are obviously more important in the world than others. Taking a look at the United States (I am German) we notice that Creationism is inconceivably important due to what ever reasons. But still it’s nonsense.
        It is necessary to fight pseudoscience where ever it pops up. Many people believe in it, and can’t tell what’s real and what’s not. And if you fell prey to one pseudoscience, why not to others as well? Having taken one step the next ones are only easier.
        Therefore, we must show any non-scientist what is scientific real and what is not. We cannot admit that people get false ideas of science, because they also get wrong ideas of other things which are even more dangerous (the Anti-Vax movement is severely dangerous!!).

        I guess that is at least one point, why it’s worth fighting. And there are many more, I presume.

      3. i appreciate the honesty of your answer. i had never thought of it that way before. you view it as a battle of truth vs. fallacy. what i find difficult to understand is why you would waste valuable time engaging in debate (or derision in salacious’ case) with someone who supports a theory that is so difficult to accept that it will never have more than a fringe following.

        the commenters on this site seem generally to have an above average knowledge level of cosmology, physics, etc… i don’t think any of these people are going to be swayed in their opinions from mainstream cosmology over to the EU camp. what do people hope to accomplish by arguing with this guy thread after thread? he won’t change his mind and noone else will believe him so it’s really just a stalemate.

      4. @DrFlimmer: I think Creationism is important here because of the major Puritan influence that was here at the start of the country. You would think, however, that we would have gotten beyond that, but here in this country, and especially in the south where I live, being atheist or agnostic will get you rejected by the community. They feel that people who follow these ideas are immoral people, who do whatever they please regardless of how it effects others. They see us as no different than murderers or rapists, because they feel that the only morality comes from god. It’s a load of crap, and I just don’t understand how so many people can be duped by the nonsense of Creationism, which I personally feel has led to many morally wrong decisions over the centuries, that still continue to this day.

      5. The important point in raising objections to pseudo-science is not to convert those who have their minds marinated in the stuff. It is to illustrate to others what the problems are so they might at least give a second consideration on the matter. A creationist will most likely go to their grave convinced of their rectitude about “science.” However, what we can do is to limit the number of people who are enticed into accepting their nonsense. In that way pseudo-science is kept down as a minority position and held under a spotlight of skepticism.


      6. @ Question

        The time is not so much wasted as you imagine. In fact, I for myself learned during these discussions. Because in order to show the fallacy of the “opponent”, I had to look things up, and revise my knowledge especially of plasma physics.

        Concerning the knowledge of the people here: I know that HSBC and LBC are scientists, and so am I (got my Masters degree and started my PhD work last year). Of others, I can’t tell.

        @ Jim

        One of the weired things is that from time to time especially those who pretend to believe in (a Christian) God and live a “life worthy for him” do some really bad things. They do what they claim would an atheist normally do. Kind of “double moral standards”. Quite dangerous.

        @ Lawrence B. Crowell

        I second your statement!

Comments are closed.