EPIC: Astronomers may have photographed a black hole for the very first time

This could be the biggest announcement ever in the history of astronomy. Announcement and video follows.

Artist conception of what a photograph of the event horizon around a black hole may look like.

Of all the weird stuff that exists in the universe, such as quasars, pulsars, magnetars, neutron stars, red giants and white dwarfs, one of the most bizarre, and the “holy grail” for scientists to image, is the black hole. Black holes were first identified in Einstein’s theory of general relativity. These gravitational monsters create a gravity well so deep and so steep that they consume everything near them. The gravity is so intense that even light can’t escape. While science already knows quite a bit about black holes, and have posited that one exists at the center of our galaxy since the mid 1970s, there have never been any photographs of black holes. After all, how can you photograph something that sucks in all the light around it?

The answer? Look for the event horizon.

That lack of photography may be about to change on April 10th, 2019. From the EHT webpage:

The European Commission, European Research Council, and the Event Horizon Telescope (EHT) project will hold a press conference to present a groundbreaking result from the EHT.

  • When: On 10 April 2019 at 15:00 CEST
  • Where: The press conference will be held at the Berlaymont Building, Rue de la Loi (Wetstraat) 200, B-1049 Brussels, Belgium. The event will be introduced by European Commissioner for Research, Science and Innovation, Carlos Moedas, and will feature presentations by the researchers behind this result.
  • What: A press conference to present a groundbreaking result from the EHT.
  • Who: The European Commissioner for Research, Science and Innovation, Carlos Moedas, will deliver remarks. Anton Zensus, Chair of the EHT Collaboration Board will also make remarks and introduce a panel of EHT researchers who will explain the result and answer questions:
    • Heino Falcke, Radboud University, Nijmegen, The Netherlands (Chair of the EHT Science Council)
    • Monika Mościbrodzka, Radboud University, Nijmegen, The Netherlands (EHT Working Group Coordinator)
    • Luciano Rezzolla, Goethe Universität, Frankfurt, Germany (EHT Board Member)
    • Eduardo Ros, Max-Planck-Institut für Radioastronomie, Bonn, Germany, (EHT Board Secretary)

The conference will be streamed online on the ESO websiteby the ERC, and on social media. We will take a few questions from social media using the hashtag #AskEHTeu.

An ESO press release will be publicly issued shortly after the start of the conference at 15:07 CEST. Translations of the press release will be available in multiple languages, along with extensive supporting audiovisual material.

A total of six major press conferences will be held simultaneously around the globe in Belgium (Brussels, English), Chile (Santiago, Spanish), Shanghai (Mandarin), Japan (Tokyo, Japanese), Taipei (Mandarin), and USA (Washington, D.C., English).

The European Commissioner for Research, Science and Innovation, Carlos Moedas will speak in Brussels, the President of the Academia Sinica, James Liao, will speak in Taipei, the ALMA Director Sean Dougherty and the ESO Director General Xavier Barcons will speak in Santiago, and the NSF Director France A. Córdova will speak in Washington DC.  

Due to the importance of this result, we encourage satellite events in the different ESO Member States and beyond. If you wish to arrange a satellite event please contact Katharina Königstein (k.konigstein@astro.ru.nl) for details on the live feed. There are satellite-events currently planned in Madrid, Rome, Gothenburg, Nijmegen and Pretoria.

For any further information and updates, please also check the Event Horizon Telescope webpage at https://eventhorizontelescope.org.


113 thoughts on “EPIC: Astronomers may have photographed a black hole for the very first time

    • I often thought they should have a series of 24 telescopes in equitorial geostationary orbit with one in each of the 24 timezones and all linked together effectively creating a telescope with a diameter of 22,236+22,236+8,000=54,472 miles

        • Sometime before NASA expires under the weight Crony Scientism and normal bureaucratic decay, I hope they launch a series of telescope arrays with the effective aperture of earth’s orbit or more (cover the whole EM spectrum – and able to aim in any direction)..Build them to last a couple centuries. Then turn them loose to do some uber astronomy.

          • Did miss the /sarc?
            Couple of centuries? The hardware maybe, but radiation takes its toll. And what pray tell do you suggest we use for power? Solar panels don’t last centuries. It would have to be supercharged RTGs (Radiographic Thermal Generators) much better than the thing Matt Damon lugged about on Mars (which BTW doesn’t weigh all that much on Mars).
            And fuel for station keeping, repositioning and aiming? That takes good old reaction thrusters and fuel, …centuries worth.

            Rocket science is easy…rocket engineering is a bitch!

        • Yeah, you have the aperture of the earth but don’t have the resolving power of the diameter of the earth. So the noise is still bad. You just get to see small, noisy objects.

          • Sorry I wasn’t specific. I was referring to Radio Telescopes rather than Visual light. Though Visual or Full Spectrum might still prove interesting, results wise

  1. “Astronomers may have photographed a black hole for the very first time”

    “That lack of photography may be about to change on April 10th, 2019. ”

    may have ( something which has – possibly – already occured ) ; may be about to : NOTHING has happened yet.

    What ever happened to science knowing the difference between observation and mental masturbation?

    • A black hole, by definition, emits no light.
      Photography is based on gathering light.
      So, let’s be clear: There will never be a photograph of a black hole.
      It is logically impossible, by definition.
      Film at 11:00®

      In other news:

      At the right margin of this comment, I am attaching my complete set of photographs of invisible men, and women too!

      • Not the BH proper But the EH and accretion disk emit light
        Also the galaxy beyond emits light which is bent around the BH

      • Apart from X rays emitted from accretion (Eddington limit) and some space distortion behind the BH …

        Perhaps the photo will be taken in the X spectrum.

        • So it’s not a photo and it’s not of a black hole. Apart from that and the “may have” disclaimer, it’s totally factual sciency stuff.

          • Greg, you’re so full of “it”. When we photograph the silhouette of an object on Earth, can we not infer the nature of the unseen object –especially when it’s major characteristic is that CANNOT be seen?

            Can we not deduce from the appearance of the objects outside the black region the physical nature of the object itself?

            Ditto when we obtain images of objects in other than the visible spectrum?

            Your crabbed and prissy comments would, if applied to images of otherinterstellar or extra-glalactic objects, would sound like this:

            “That’s not a photo of the Crab Nebula, that’s a series of images taken at different wavelengths of what the Crab Nebula looked a long, long time ago.”


          • Are you trying to claim that the X-rays of my dislocated finger are not photos, just because the light used to image them was not in the visible region of the spectrum? Stuff and nonsense.

          • Anna Keppa: +100

            And I don’t understand all the dissing by some. If the accretion disk (@ 30000 light years away!) could be imaged, even roughly, that would be amazing IMO.

        • Need not be x rays, and probably not as radiation evaporating from the holes is mightily red shifted by the compression, Hawking radiation is thought to result from virtual particle/antiparticle pairs where the negative one gets chewed and the positive escapes as radiation. Hawking radiation has allegedly been imaged before.

      • Ever hear of silhouettes? That’s probably not exactly what this is, since (as Bryan A mentions) the light from objects behind the black hole gets bet around the hole; but it’s not the case that you can’t photograph objects that emit little or no light.

        • You cannot photograph an object that emits no light. Not sure why any one is arguing about that? And x-rays exposing photoemulsion are not making a photograph, unless you want to redefine what a photograph is to include all wavelengths. Just redefining a word to make your argument us not much of an argument though.

          • I doubt that I have read a more naive comment on this thread. Anything that acts like a wave, can be focused to form an image. And if that image can be made visible, then it can be photographed. I guess the commenter has never heard of an electron microscope. Electrons are definitely not light, but they can act as waves, they can be focused to form an image, and that image can be made visible and photographed.

            They are taking advantage of electromagnetic waves a the 1mm wavelength. Such waves appear to be emitted by the object known as Sagittarius A*. Unlike light, 1mm waves can pass through the dust and gas that are blocking our view of the object.

            A 1mm wave lies in the region between microwaves and infrared on the electromagnetic spectrum. Of course, they act like waves, they can be focused to form an image, and that image can be made visible and photographed.


      • Based on this argument, no one has ever *actually* photographed any physical object – – they’ve only ever photographed the pattern of photons emitted by and/or absorbed by the object. Which is a distinction without a difference as that is what photography *really* is.

        Photography is actually the process of recording the pattern of visible-spectrum photons emitted, reflected, occluded, or absorbed by a volume of space & incident upon the lens and sensor of a camera or other sensing device.

        Black holes can most certainly be photographed, based on their influence on photons emitted by other objects. Which is how the vast majority of ‘things’ are photographed.

  2. I hate to be a party pooper, but it looks like a lot of hype to me.

    Next week, I will be unveiling my photo of a never-before-seen photo of nothing. Nobody has ever seen nothing, and so this will be an earth shattering breakthrough.

    Many have theorized about what nothing looks like, but nobody has ever seen nothing.

    Nothing like this news about nothing has ever broken before.

    Okay, you can delete my rant about nothing now, since it contributes nothing to the post.

    But wait, if it can contribute, then this is a form of negative contribution, which IS something about nothing, and so this nothing is, in fact, a bit of something.

    Obviously, I’m not a fan of “black holes”, “dark matter”, and the like.

  3. Let me know when a breakthrough photo of a live-dead cat is on the horizon. Or an exploded-not-exploded bomb.

    Twenty-three-dimensional photography would be a great breakthrough for super-string theory. Can’t wait for that.

    I’m such a spoil sport. Admitting my problem is the first step.

    • Being a spoil sport isn’t a problem. One of the things that leads to disaster is group think. Only a properly motivated, skilled skeptic can prevent that. link When people quit listening to skeptics you get things like climate science.

  4. Is it an event (occurring within a finite period of time) horizon, or is it actually a process horizon?

    • At the event horizon, gravity warps space-time so much that physics just breaks. Time itself stops.

      Suppose that we were able to see a newly formed pulsar (still hot) get consumed in a head-on collision. Before things get appreciably relativistic, it is seen spinning at 400 Hz. Now also suppose that this is a super-massive variety of black hole, so that the tidal forces won’t rip the pulsar apart before the fun starts. Now from our (safe) vantage point, the pulsar will slow down and turn red. Eventually the pulsar stops moving from our perspective, and has become so red-shifted that it can only be seen in the radio spectrum. Then, after appearing frozen, it winks out altogether, and is gone.

      What the pulsar feels, well, nothing really. The spaghettification (yeah, that’s the actual term) would be instant. As the gravitational acceleration exceeds the possible speed of light, time dilates infinitely, and thus stops. Game over.

      • Thanks much Patrick, that clarified it for me. Astrophysics seems hard for my mechanical engineering mind to grasp.

      • Patrick,
        The physics don’t break at the event horizon. There is only a singularity in the coordinates. Changing to Kruskal coordinates removes this singularity. Only time and distance (to the center) are interchanged.
        The singularity is in the center, known physics don’t apply. Probably there is no mass (as particles) anymore, just curvature.
        A solar mass black hole has a Hawking temperature of 62 nK, impossible to detect.
        You can visualize a black hole by detecting the scattered photons. An eye does not see objects, it detects photons. However, the interpretation by the brain is very suggestive.

      • Time only dilates infinitely from our side. From the inside, the mass itself causes a space dimension to become a time dimension, and our time dimension becomes another space dimension. So, our outside becomes their past, our “center” becomes their future expanding universe and new mass comes flooding in in an inflationary event to fill the new space.

      • Here in the Astrophysics Curio Shop, if you break it you bought it! Please keep your hands inside the ride.

  5. Guys, lighten up. If you watch the movie, it says they gathered the data more than a year ago, and have been processing it since then to see if they got the “picture”. They are using 1mm wavelengths, and have to assemble huge amounts of data from six or more radio telescopes around the globe. If they are having a press conference this big, it undoubtably means that they have got the result. The other think likely to be announced is confirmation of Einstein’s equations predicting the black hole “event horizon”, and perhaps some other prediction confirmations (Hawking??). In any case, it’s worth a look.

    • Further to this, it occurred to me that using Einstein’s predictions and the observed size of the event horizon, they may be able to “weigh” the black hole, a huge first. Size of the Milky Way black hole has only been roughly estimated at this point, and nobody has any idea if they got it right.

      • I thought he had thew weight down first.. after all, it was the missing mass needed to explain why the galaxy acts the way it does. The solar system has a honking great mass in the center to hold everything in orbit.. ergo the galaxy must too!

        Oh unless there’s a binary spin created first between two moderately large objects, not galaxy-holding level large, just large which can then drag other stuff into the same oscillation attraction pattern.. but then you’d end up with a galaxy that had spiral arm type things and some sort of weird bar shaped core.

        ..oh ..

        • Actually, the central black hole is not the missing mass. We know where the center of galaxy is; the missing mass (dark matter or dark energy or something more exotic) has mass and approximate locations, but because it’s dark, no exact location. A lot of the dark mass is at the edges of the galaxy, spacewise. We know this by observing that the speeds of objects far from the core are traveling at speeds too fast, compared to objects closer in. There are several problems with this, not just the ,ass, as the spiral arms should only exist for 150 million to 300 million years before getting completely out of sync, and all current theories of the galaxy suppose that it is 5-13 billion years old. This is a significant mismatch. There are theories, but no good ones.

    • “They are using 1mm wavelengths…”

      They will need to colorize the data?
      It will not look like a black hole, but like Disney would like you to visualize a black hole.
      If you were in space to be able to “see” a black hole, you would not see a black hole.

    • Thanks for the sound reaction. Some doubt about everything, even about time dilation!

      Such people I like to name the ‘pseudoskeptic’s because they use to name all what they don’t understand ‘pseudoscience’.

  6. Way too much hype. I’m not knocking the accomplishment. But “The biggest announcement ever in the history of astronomy.”? Multiple press conferences all over the world? Surely the Apollo 11 discovery in 1969 that the moon was in fact actually made up of green cheese was far more significant.

    • I still can’t believe that the National Dairy Council has been so successful at suppressing that finding. If not for them, we might have been able to maintain the space programs momentum with the profits from imported Moon cheese.

      I’ve heard that Musk is keeping his plans for Lunar Cheese Mining close to the vest, lest he run in to ubstruction from Minnesota.


      • You’re right. You can’t get there from here. But there is a place just down the road and you can get there from there.

  7. On September 15, 2015 Astrophysicusts “imaged” the gravitational signature of a binary blackhole merger. To the limits of instrument measurement uncertainty, the waveform had precusely the characteristics as predicted by Einstein’s GR formulation. And that was “seeing” the final ~250 milliseconds of two blackholes as they merged into a single event horizon.

  8. Curious video post! This is astrophysics! Video recording the speakers is ridiculous, where are the slides they were referencing? Ahhhh!

  9. As the event is sponsored by the European Commission and they wish to make an announcement, I am reasonably confident they will say, having studied the output of the EU over many years and in great detail they have concluded, it is itself a black hole. It consumes everything and produces nothing.

    • As the event is planned to occur just before the EU elections, I am very sceptical that this is any more than sciency agitprop.

      • CO2 makes black holes worse, we’re all doomed! (That’s why the EU have to increase taxation). 😉

    • If two Neutron stars merged, and the gravitational waves were detected, and a Black Hole was the result, and they have photographs of the before and after conditions, that would be a great moment in Astronomy.

  10. Additionally as far as I’m aware, Hawking radiation has never been or ever likely to be detected with our current instrumentation.
    Prof.SWH admitted that Black Holes are ‘Grey’ & not really holes (similar to the badly named Big Bang).
    Majority of folks believe BH’s exist event before ‘we’ have proved they actually do, (there are 5 other theories) but yes the evidence is getting stronger.

    • Philosophy trending science. That’s good, as far as inference goes. Next step is the solar horizon, which we have only once skirted in close proximity.

  11. How hard can it be to write clearly? Compare:

    Version 1. “While science already knows quite a bit about black holes, and have posited that one exists at the center of our galaxy since the mid 1970s, there have never been any photographs of black holes.”

    Version 2. While science already knows quite a bit about black holes, and have posited since the mid 1970s that one exists at the center of our galaxy, there have never been any photographs of black holes.

    So how old is the black hole likely to be: billions of years or about 45 years?

  12. Will Ann Schwab declare a Block Hole Emergency to follow up on her Climate Emergency.?

    Why not, the Chico City Council has proven they can fix anything.

  13. The irony of course is that if you showed nearly anyone in a first world country the picture at the top of the page without any caption, they would immediately identify it as a Black Hole.


  14. How do you photograph a black hole? How do you photograph something so far away? You can’t be talking about photography in the usual sense. Aren’t we talking about telemetry and computer generated images?

    • Yes, it is telemetry and uses electronic signals to generate an image, but isn’t that almost exactly what the digital camera in your smart phone does? They are just making a very big aperture using dispersed imaging radio-telescopes.
      I assume they have photographed ‘the effects of a black hole’ as it bends light passing near it acting as a gravitational lens.
      Like the beautiful poem mentioned in above comments you cannot photograph the wind, but you can certainly photograph its effects.

  15. If your idea of a black hole depends upon a singularity to exert curvature on space time, meaning, a sizeless point which is assigned to carry mass in order to obtain the ridiculous density to curve a mathematical space (space time), You are in for a disappointment. A black hole is definitionally NOT a gravitational black body such as Newton proposed, though there are some similarities.

    Black holes are also not mathematically compatible with Big bang theories, no matter how much you want to believe in either of them.

    Hilbert is actually the guy who created the mathematical black hole fiction by removing all matter and energy from a given space time (ric = 0), then magically reinserting the mass back into the model via meaningless linguistics without anything for the mass to be assigned to. This is actually a big no-no even according to Einstein. No finite extension of matter or energy for your mass to be assigned to, no source of gravity in your given space time. You simply don’t get a black hole in space time unless your mass is assigned to something sizeless that is definitionally not capable of carrying mass, a point. After all the talk on this site of ridiculous non-physical models not related to reality, well folks, here is one of them.

    • Worse is, accd to current accepted space-time and quantum theory, black holes cease to exist the moment they’re formed: they literally stop in time.

    • CFT

      Oh how disappointing…

      I thought the Big Bang is when the very last Black Hole in the Universe eats up the penultimate one, and realizes too late that it was the Hole too much.

    • I wonder when scientists will realize that time is not a dimension and has no dimensional qualities. Time is a perception. At some point in human brain development, in addition to reacting to the inputs via our senses, our brains make images of the inputs and send them to storage areas of the brain. We later are able to extract those images of sight, sound, smell, touch, pain, etc. and sequentially analyze them. We Observe, Record, Recall and Sequentially Analyze. Each person’s sense of time is their own. If two people are attending an event the photons that strike their retinas are not the same, the atmospheric molecules that impinge on their eardrums are not the same, nor are the pheromones detected in their nasal passages and so on. Certainly the internal sensations are unique to each individual. Then you have the fact that the receptors that gather the information aren’t all of the same quality, nor does each brain process and image the information received in the same way with the same accuracy. And time only exists for us when we are awake, alert and actively processing information. When your brain shuts down time doesn’t exist for you. (Something I learned when sleep deprived and totally physically exhausted in military training and later reinforced when undergoing colonoscopies and surgeries under anesthesia that shut my brain down.)

      Your time is yours and yours alone as we are all trapped in our own heads.

      Dimensionality implies something within which we should be able to travel. Why can’t we travel in time? Because since the big bang the universe has done its thing expanding and cooling, producing galaxies, stars, planets, moons and yes, singularities that manifest their existence by creating the so-called ‘black holes’ that exist. In order to travel in time it would be necessary to step outside of this universe and force every quantum bit of it to return to a previous location to go back in time or accelerate it to a future location to go forward. I think this may be a difficult thing to accomplish.

      • Maxwell,

        When you propose something you can’t examine or test which is forever beyond the reach of any observation (beyond the so called event horizon), don’t tell me you understand it. You don’t. Cosmology revolving around mass assigned to empty mathematical spaces and a poorly defined schwarzchild radius that even physicists can’t agree upon is not fact, or science. It’s just very poorly assigned math mixed with empty speculation.

  16. So far, we have seen “artist conceptions” only. I’ll wait until their “seminal announcement” but I have serious doubts.

  17. Was the idea of cutting the screen shots out of the frame deliberate or just a stroke of anti-genius?

  18. What will presumably be seen in the image is the radiation from infalling matter to the black hole event horizon, and background light distorted around such a huge concentration of mass. The telescope is a network of radio telescopes looking at light in the radio part of the spectrum, relying on the use of a technique called interferometry, to make a single image from the simultaneous collection of data at each of the scopes. This is relatively easy to do with radio, and we cannot see the BH region in visible light, because there is obscuring dust between us and the center of the galaxy. The radio light is not absorbed by the dust. So radio is used.

    With the use of this array telescope, the predicted 60 million km BH event horizon should be resolvable. Yes, it is real light. Radio interferometry is a real technique used for decades. Yes, they use big computing power to put the data together, but no, it’s not just a model. Yes, the “picture” will be made from the data of the radio waves collected, and analyzed by a computer, and presented in “false color” so you can see it.

    There are radio telescope “movies” of the stars close to the BH showing their orbits around it, takes over the last few decades. These show us the stars orbiting something truly immense and tiny. Google “Sagittarius A*”, the proper name of the BH, to learn more.

    And yes, it will be one of the most amazing astronomical photos ever, if they succeed.

  19. After digging deep, it seems it is the Black Hole at the Milky Way’s center that is the subject of the upcoming photographs.

    We need a set of telescopes like these spread as wide as the orbit of the Earth. I bet we could photogragh a lot of things, with hardware like that! 🙂

    We’ll be doing all sorts of things like this once humans start moving into the Earth/Moon space. Maybe less than 25 years from now.

  20. I like the artists’ conceptions better.
    I hope that some day we can replace every astronomical photo with an artist’s conception.

  21. So they may have “photographed” a mathematical fudge factor…. Amazing. It’ll probably look like a polar bear on an iceberg.

  22. A pitch for more money -to study an unverifiable event , in an unmeasurable horizon – by convoluted argument which no one can understand -and hypothesize on unknown unknowns- which cannot be falsified – I won’t hold my black hole captive , while plasma streams are clearly seen .

  23. Skepticism is the chastity of the intellect, and it is shameful to surrender it too soon or to the first comer: there is nobility in preserving it coolly and proudly through long youth, until at last, in the ripeness of instinct and discretion, it can be safely exchanged for fidelity and happiness.
    The Works of George Santayana

  24. Fed-x is faster than the Internet!

    From the video at 49min mark. Thought that was funny, but is made sense.

    • Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway.
      –Andrew Tanenbaum, 1981

      Entertainingly described at …


      But seriously, we do it all the time. We have Internet 2 connections (largest capacity network feeds, and no porn to clog up the network … unless you count some of the climate data that is surely crossing that network) and we still routinely use devices like Snowballs to move petabyte sided data sets between data centers.


      Clever packaging … LCD shipping labels, permanently attached power cords, network cable with GBIC attached for plug compatibility with any modern network switch, all in a self storing molded impact resistant case.

      [youtube https://www.youtube.com/embed/yl25W7LZAMU&w=640&h=480%5D

  25. The elephant in the room is the assumption that black holes are what we think they are. There may indeed exist gravity wells of all sorts. But I think we must be open to all kinds of systems in the heavens. The scale of rotating bodies can make for some very strange objects to observe. I think that Jefimenko made a good case for antigravity in his work with mass currents. If indeed these do exist then what we observe and what we assign to the observation may be way off. But man loves to think we have figured it all out. Just be careful that a new picture does not allow group think to take over. I like to study the non-orthodox theories. I think that is where the next leap will come from. Right now I am studying the work of Distinti on the ether and a new model of electromagnetism. If he has some things correct then a new picture from the sky may mean something completely different than what some would assume. Just be ready for more questions and no conclusions.

      • So, the event horizon has a position and a form that can register in a “photograph”?

        I still don’t get what the physical entity is that the “photograph” would capture.

        This “event horizon” seems to be defined by “events” — descriptions of actions that do not have physical forms independently or collectively as an ensemble of happenings somehow exuding a visual impression.

        The “event horizon” seems to be an imagined, conceptual boundary, based on a mathematical theory, rather than an actual thing that registers as a physical entity subject to being “photographed”.

        I’ll look at the video now, I suppose.

  26. “Black holes were first identified in Einstein’s theory of general relativity.”

    Not so. The possibility of their existence, a solar mass so great that its gravity would prevent the light from escaping, was discussed in the 19th century, probably before Einstein was out of diapers.

    • Yes. However, it would take about 10^66 years for a solar mass black hole to evaporate. And for a 4 million solar black hole, about 6.4 * 10 ^85 years. Black holes put out radiation and other mass randomly. For a large black hole, that would start with very low energy (long wavelength) photons. At its very end, a black hole should emit radiation at a temperature 5 x 10^17 Kelvins at the beginning of its final second. This is far beyond anything at CERN. At Planck time, it should emit a particle with a mass of roughly 3.4 x 10^19 atomic mass, or 3.1 x 10^28 eV. Hot!

  27. The mass of a black hole can be no greater than the mass of the original star that went supernova????????

  28. “Astronomers may have photographed a black hole for the very first time”

    So that’s what I photographed in my youth! I thought it was just unexposed film.

  29. “Black holes were first identified in Einstein’s theory of general relativity. ”

    John Mitchell, 1784.

  30. Using Newton’s law of gravitation and his second law of motion, we can, with the aid of some integral calculus, derive the equation for escape velocity:

    \displaystyle {{v}_{e}}=\sqrt{\frac{2\cdot G\cdot m}{{{r}_{s}}}},

    where \displaystyle {{v}_{e}} is escape velocity, \displaystyle G is Newton’s gravitational constant, \displaystyle m is the mass of the body, and \displaystyle {{r}_{s}} is the surface radius of the body.

    Escape velocity is the velocity required to completely leave a gravitational body and never return. We can rearrange the terms of this equation and solve for radius:

    \displaystyle {{r}_{s}}=\frac{2\cdot G\cdot m}{{{v}_{e}}^{2}}

    or radius is inversely proportional to the square of escape velocity. If we increase the escape velocity of a mass, then the surface radius decreases. Increase escape velocity to the speed-of-light will give us the event horizon of a mass. This is also call the Schwarzchild radius:

    \displaystyle {{r}_{s}}=\frac{2\cdot G\cdot m}{{{c}^{2}}},

    where \displaystyle c is the speed-of-light. Notice that this is still classical Newtonian physics–I’m not using General Relativity at all. Saying that Newton doesn’t predict black bodies isn’t exactly true.

    Let’s solve for the Earth: \displaystyle G = 6.674E-11 m^3 kg^-1 s ^-2, \displaystyle m = 5.9722E24 kg, and \displaystyle c = 2.99792458E8 m/s; and we get 0.887 cm. If we made the Earth a black hole, it would have an event horizon of about 7/10 of an inch across.

    Now let’s apply this to Sagittarius A*, the massive black hole at the center of our galaxy. It’s mass is estimated at 4.31E6 solar masses and a solar mass is 1.989E30 kg. Plugging these values into the equation gives us 1.273E10 meters.

    To get some feel for this number, we’ll convert to astronomical units. The average distance of the Earth from the Sun is defined as an astronomical unit or is about 1.49597E11 meters. If we divide by this number we get 8.51 Au.

    Jupiter’s distance is 5.2 Au and Saturn’s is 9.5 Au. The event horizon of the massive black hole would be just inside the orbit of Saturn if it was at the center of our Solar System.


    • It is my understanding that the Schwarzchild solution requires:
      that the rotating angular momentum = 0,
      the charge = 0,
      and the cosmological constant = 0,
      in a vacuum.
      Sagittarius A* is in the middle of a rotating galaxy that is not a vacuum but full of gaseous plasma and stars.
      Question: what happens to the angular momentum of the accretion disk in a rotating field of matter?

      • Well, I was using classical Newtonian physics, so it doesn’t seem to apply to anything but a Schwarzchild black hole. It sounds like you want a Kerr black hole, or something like it.

        Question: what happens to the angular momentum of the accretion disk in a rotating field of matter?

        Nothing. Angular momentum is conserved.


        • Jim, I am merely pointing out a major problem that afflicts these discussions about ‘science by press release’.
          People refer to black holes, super massive black holes, Schwarzchild radius, singularities, event horizons, mergers of neutron stars and black holes, ad infinitum. We invoke Newton and Einstein, Schwarzchild, Kerr, Kerr-Newman, Reissner-Nordstrom, and we tend to mix and match the parts we like and discard the parts that are inconvenient.
          This type of press release seldom if ever defines which of the 4 different types of black hole they are looking for (as you say, probably Kerr). Do all 4 types exist? Certainly not. Do any exist? Maybe. They are all mathematical constructs or solutions.
          The problem with both Kerr and Schwarzchild solutions is they both are described as being surrounded by empty spacetime. I.E a Vacuum.
          Reissner-Nordstrom is a static solution in which Nothing Is Moving.
          Kerr-Newman …”describes the spacetime geometry in the region surrounding a charged, rotating mass. This solution has not been especially useful for describing astrophysical phenomena, because observed astronomical objects do not possess an appreciable net electric charge.”(Wiki)
          So in summary none of these black holes describe what We see when We look at the universe.
          How can a Kerr black hole surrounded by empty space time pull Anything into it if it is surrounded by Nothing?
          I enjoy your comments, I just have lots of questions I guess.

          • Mathematicians have created black holes inside their mathematical laboratories, black holes isolated by definition inside a universe with only one central mass.
            They then remove the black holes from isolation and plunk them down willy nilly in our universe that is populated by Billions of massive objects, including other black holes. They even get to smash black holes together.
            Not bad for an object that originates and exists isolated in a one mass universe.

  31. Does the hour-long video actually show this new photo of the area around a black hole? Or is this just a tease? Let me know when the photo is actually available to the public.

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