Saturday science subject: Seeing a black hole

Einstein’s general theory of relativity predicts the existence of black holes, but nobody’s ever actually seen one. As New Scientist reports, however, a team led by Shep Doeleman of MIT’s Haystack Observatory is working to snap the first images of the supermassive black hole at the center of our galaxy.

That’s no easy task. The object lies 30,000 light years away from Earth, and although it has about 4.5 million times the mass of our Sun, it’s also only about the size of the “inner solar system.” To put things in perspective, New Scientists says imaging Sagittarius A*’s event horizon (the point of no return for light around a black hole) is like trying to get a picture of a football on the Moon.

How do Doeleman and his team plan to do it?

No ordinary telescope could see such a small dark smudge. Instead, Doeleman is using a well-tested technique called very long baseline interferometry or VLBI. By combining the observations from widely separated dishes across the planet, radio astronomers can effectively reconstruct what would be seen by one enormous dish – even one as large as the Earth (see map). Because small dishes collect less light, a VLBI image is less bright than the image from a real planet-sized dish would be, but it can reveal just as much detail.

Using the part-built VLBI device, the team has already captured images “almost good enough” to show Sagittarius A*. You can see them in the gallery below, courtesy of nasaimages.org.

Of course, even though general relativity calls for Sagittarius A* to be a supermassive black hole, Doeleman and his team could end up with an image of something else. New Scientist says the team might see a boson star or something stranger yetโ€”like an event horizon in a weird shape. That would imply relativity “is radically wrong when it comes to super-strong gravity,” the article says.

Comments closed
    • rechicero
    • 11 years ago

    In fact, Black Holes should be black if we use Einstein relativity, but quantum physics predicts that a Black Hole emit some kind of radiation…

      • Meadows
      • 11 years ago

      That’s not a prediction, that’s a fact.

      It doesn’t change the colour of the black holes though, because the radiation is not within the scope of your eyes.

        • eitje
        • 11 years ago

        It is *[

    • Krogoth
    • 11 years ago

    You *cannot* see the black hole itself. It is impossible since light inside of it cannot escape. You are only are able to see up to the “Event Horizon” a.k.a point where light cannot escape it’s gravitational influence.

    The event horizon would look like “wrapped space” as light and matter coming near it gets distorted by the extreme gravity. You will also see first-hand the effects of relativity.

      • Krogoth
      • 11 years ago

      Sorry, Double post……

      • eitje
      • 11 years ago

      I think you mean that we cannot see the singularity itself.

      The space a black hole occupies is defined by its event horizon, thus we must be able to detect the black hole via its event horizon. I agree that everything inside the event horizon is “undefined” with relation to our universe, though.

      Example: Would you say that we cannot really see an apple, because the skin conceals everything beneath it? I would say we cannot see an apple’s core, but we can still see the apple.

        • Meadows
        • 11 years ago

        You are assuming that there is a rule in physics allowing so much matter to occupy a single point.

        That’s a lot of assumption in very little space (pun not intended). It’s a mild hypothesis with absolutely no sort of proof to come.

        Whatever the case though, Krogoth remains right that you can’t see anything but the silhouette of the event horizon (which practically isn’t part of the celestial body itself), and even if you saw anything, it would only be an, err, black hole in a viewscape otherwise full of stars or dust.

          • SPOOFE
          • 11 years ago

          /[

            • Meadows
            • 11 years ago

            That’s a bold statement to make, considering it’s hard to talk about “zero-dimensional objects” (ergo the “point”, which is just a theoretical mathematical construct to denote a position in a system), let alone talk about how they behave.

            A black hole behaves like a black hole. You don’t know how a point behaves, and you don’t have to.

            • eitje
            • 11 years ago

            How about you try producing some links, rather than just casting aspersions.

            • Meadows
            • 11 years ago

            ยง[<http://en.wikipedia.org/wiki/Point_%28geometry%29<]ยง This is the same reason why string theory is cloudy - "vibrating, one-dimensional strings, approximately one Planck-length each". If it's one-dimensional, then it can't have a length. Poof, physicists fail. That's all you should really know about theories.

            • SPOOFE
            • 11 years ago

            For all your talk about doubtful theories, you sure spew a lot of crap.

            /[

            • Meadows
            • 11 years ago

            Indeed, that was an incorrect “sleepy tangent”, but my, uhh, points stand outside that.

            • SPOOFE
            • 11 years ago

            I doubt you still remember what your point was, but no, your point does not still stand.

            • nerdrage
            • 11 years ago

            q[

            • Meadows
            • 11 years ago

            Yeah, I admit, it was late at night and “one” and “zero” slowly converged in my head while arguing online.

            • SPOOFE
            • 11 years ago

            It’s not at all hard to talk about zero-dimensional objects; we’re doing it right now!

            The point is that your commentary about the uncertainty of the existence of a singularity, while accurate, is also irrelevent. A “black hole” is the event horizon. When they say they’re trying to see a “black hole”, they’re talking about trying to locate the apparent area of space occupied by the mathematically defined space where light cannot escape. That’s it.

            • zima
            • 11 years ago

            /[

          • eitje
          • 11 years ago

          q[

            • Meadows
            • 11 years ago

            You mentioned the singularity, which is a theoretical /[

            • eitje
            • 11 years ago

            I mentioned the singularity only in reference to the fact that we cannot currently detect or determine what is inside of an event horizon.

            frankly, the point (haha) where you said I was making up rules of physics was left-field and trollish, since the very purpose of bringing the concept of the singularity into play was to mention that we cannot prove or disprove its existence, since the rules of physics break down from our perspective once we’re beyond the event horizon.

            if you’re going to take offense to my use of the word “singularity”, what name SHOULD I have used, then, to refer to the mass which lies beyond the event horizon which defines the edges of a black hole?

            • Meadows
            • 11 years ago

            Well, I tend to call the celestial body a “black hole”, but if you refer to the entire event horizon volume as black hole then you could perhaps use “dark star” for the celestial body.

            This is an outdated and often inaccurate term, though. The fundamentals are the same, a dark star is a celestial body with an escape velocity of c minimum, but there can be theoretical differences.

            • zima
            • 11 years ago

            From your description of singularity it’s evident that you don’t have a clue what that concept actually is.

            And…you point it’s weaknesses? Please…

    • Krogoth
    • 11 years ago

    Nitpick, you had spelled Sagittarius wrong. ๐Ÿ˜‰

      • Meadows
      • 11 years ago

      Nitpick, you had spelled a past tense wrong. Again.

        • Krogoth
        • 11 years ago

        Big deal, Mister Grammar.

          • flip-mode
          • 11 years ago

          FAIL: when you misspell a word while picking on someone for misspelling a word.

            • Krogoth
            • 11 years ago

            It is called irony my friend.

            • eitje
            • 11 years ago

            whatever it is, it’s still funny at your expense.

    • Jypster
    • 11 years ago

    Very much looking fowrard to the results of this project. Some interesting finds and even more questions should come out of the research. The effect of the event horizion and other gravity sources on the synchrotron emissions along the magnetic filed lines in dynamic gravitational environment just for one.

    Considering some stars in this area are traveling between 500 and 1000 km/s would this have an effect on the event horizion shape as they ponder in the article as this would have repercussions on many of our theories. Anyways interesting results should come. Will be keeping an eye on this one for sure

    • Umbragen
    • 11 years ago

    Holly: Well, the thing about a black hole – its main distinguishing feature – is it’s black. And the thing about space, the colour of space, your basic space colour, is black. So how are you supposed to see them?

    • ssidbroadcast
    • 11 years ago

    Boring: I already saw a couple of black holes two weeks ago that were pretty massive. You shoulda seen the size of the ship emerging from it, though.

      • SecretMaster
      • 11 years ago

      SPOCK!!!!!!!!!!!!!!!!!!

      • MadManOriginal
      • 11 years ago

      Putting a mirror in your toilet after eating Mexican food doesn’t count.

        • ssidbroadcast
        • 11 years ago

        Oo, s[

          • MadManOriginal
          • 11 years ago

          While I’m certainly sorry to hear that it is really just tmi!

    • Meadows
    • 11 years ago

    There is just one big problem with the “see map” link.

    A black hole doesn’t look like an ice cream cone.

      • Saber Cherry
      • 11 years ago

      That’s a funnel spider web, not an ice-cream cone. And black holes are really much like funnel spiders, though they lack the distinctive smell.

        • Meadows
        • 11 years ago

        They maybe are similar somewhat, but they still don’t look like anything related. ๐Ÿ˜‰

    • kvndoom
    • 11 years ago

    I’ll just wait for the LHC to go live. Nothing like front row seats. ๐Ÿ˜€

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