Comments on: First Ever Images of Supermassive Black Hole From Center of Our Galaxy coming soon https://habitablezone.com/2017/12/20/first-ever-images-of-supermassive-black-hole-from-center-of-our-galaxy-coming-soon/ Sun, 19 Apr 2026 21:38:00 -0700 hourly 1 http://wordpress.org/?v=3.3.1 By: hank https://habitablezone.com/2017/12/20/first-ever-images-of-supermassive-black-hole-from-center-of-our-galaxy-coming-soon/#comment-40716 hank Fri, 22 Dec 2017 01:52:41 +0000 https://habitablezone.com/?p=68361#comment-40716 Of course, there is still plenty to see. The black hole may itself be tiny, and black, but no doubt there will be lots of gas and dust spiralling into it, glowing white hot all across the spectrum. I presume the images will be painted not in light, but in radio waves. This technique, Very Long Baseline Interferometry (VLBI) operates using multiple radio telescopes simultaneously collecting signals from the object, and the interference patterns created by these wave fronts interfering with one another will be unscrambled and reconstructed to form an actual black and white picture of the object as it glows in radio waves. All telescopes create images, and the sensitivity (how faint) of the image is determined by size of the lens, mirror, or in this case, antenna. Sensitivity goes up as the square of the collector size. So, for example, a 100 inch telescope image of a distant light source will be one fourth as bright as as a 200 inch telescope image of the same object. On the other hand, the <em>resolution</em> of a telescope goes up as the linear dimension of the collector; a 100 inch mirror will see half the detail of a 200 inch. The trick in radio interferometry is that TWO identical telescopes will collect twice as much light, but with VLBI, the resolution will depend on the DISTANCE, or baseline, between the two, not their sizes. So for example, two telescopes a mile apart will have the resolution of a telescope a mile wide. And in VLBI, the telescopes can be hundreds, even thousand of miles apart, at opposite ends of the earth. The signals from each are synchronized with atomic clocks, and the interference patterns unscrambled to form images. Of course, the math is dreadful, because the earth is rotating and moving and the geometry of the telescopes and object is constantly changing. It used to be done with mirrors and lenses and diffraction gratings in the olden days, then when radio came along it was done by filters and tuners and oscillators. Now, its all digital. Its a horrendous computing task, which is why it will take so long, even with supercomputers, but the result will be resolutions of the radio images comparable to those of optical telescope resolutions, even at radio wavelengths, in the second of arc range. And the interstellar medium is transparent to microwave radiation. Not only will we get a detailed look, it will be clear as well. If the material spiralling into the hole is indeed spiralling, or filamentary, amorphous, granular, striated or shaped like a torus, or ring, turbulent or laminar, we'll know. If it is chaotic, or organized, we'll know, and we'll be able to infer much of the physics, too. We will know what this thing looks like, maybe not the hole itself, but the shimmering complex of destruction it is organizing around itself. We will not just see a fuzzy glow of radiation, if it has structure we'll be able to see what it looks like-- in 3D and in color (different radio frequencies). SgrA* is about 8000 pc away, so if we can achieve resolution on the order of 1 arc second, we'll be able to make out individual features, like ripples, standing waves or knots of condensation in the rotating cloud as small as 0.13 light years across. And its only a matter of time before we'll be able to orbit radio telescopes in distant parts of the solar system, with interferometer baselines of hundreds of thousands, millions or even billions of miles. <a href="https://www.youtube.com/watch?v=kbG3N51MEjM" rel="nofollow">totally unrelated video</a> https://www.youtube.com/watch?v=kbG3N51MEjM Of course, there is still plenty to see. The black hole may itself be tiny, and black, but no doubt there will be lots of gas and dust spiralling into it, glowing white hot all across the spectrum. I presume the images will be painted not in light, but in radio waves. This technique, Very Long Baseline Interferometry (VLBI) operates using multiple radio telescopes simultaneously collecting signals from the object, and the interference patterns created by these wave fronts interfering with one another will be unscrambled and reconstructed to form an actual black and white picture of the object as it glows in radio waves.

All telescopes create images, and the sensitivity (how faint) of the image is determined by size of the lens, mirror, or in this case, antenna. Sensitivity goes up as the square of the collector size. So, for example, a 100 inch telescope image of a distant light source will be one fourth as bright as as a 200 inch telescope image of the same object. On the other hand, the resolution of a telescope goes up as the linear dimension of the collector; a 100 inch mirror will see half the detail of a 200 inch.

The trick in radio interferometry is that TWO identical telescopes will collect twice as much light, but with VLBI, the resolution will depend on the DISTANCE, or baseline, between the two, not their sizes. So for example, two telescopes a mile apart will have the resolution of a telescope a mile wide. And in VLBI, the telescopes can be hundreds, even thousand of miles apart, at opposite ends of the earth. The signals from each are synchronized with atomic clocks, and the interference patterns unscrambled to form images.

Of course, the math is dreadful, because the earth is rotating and moving and the geometry of the telescopes and object is constantly changing. It used to be done with mirrors and lenses and diffraction gratings in the olden days, then when radio came along it was done by filters and tuners and oscillators. Now, its all digital.

Its a horrendous computing task, which is why it will take so long, even with supercomputers, but the result will be resolutions of the radio images comparable to those of optical telescope resolutions, even at radio wavelengths, in the second of arc range. And the interstellar medium is transparent to microwave radiation. Not only will we get a detailed look, it will be clear as well. If the material spiralling into the hole is indeed spiralling, or filamentary, amorphous, granular, striated or shaped like a torus, or ring, turbulent or laminar, we’ll know. If it is chaotic, or organized, we’ll know, and we’ll be able to infer much of the physics, too. We will know what this thing looks like, maybe not the hole itself, but the shimmering complex of destruction it is organizing around itself. We will not just see a fuzzy glow of radiation, if it has structure we’ll be able to see what it looks like– in 3D and in color (different radio frequencies).

SgrA* is about 8000 pc away, so if we can achieve resolution on the order of 1 arc second, we’ll be able to make out individual features, like ripples, standing waves or knots of condensation in the rotating cloud as small as 0.13 light years across.

And its only a matter of time before we’ll be able to orbit radio telescopes in distant parts of the solar system, with interferometer baselines of hundreds of thousands, millions or even billions of miles.

totally unrelated video

https://www.youtube.com/watch?v=kbG3N51MEjM

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