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Picture of a black hole?

Picture of a black hole?

Science

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Apparently on Wednesday they are taking a picture of a black hole. First time ever.

https://www.usatoday.com/story/news/nation/2019/04/08/black-hole-photo-what-we-see-and-how-we-see-it-einstein-wrong/3401085002/

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Picture already taken.
They are releasing it on Wednesday.

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@chessturd said
Picture already taken.
They are releasing it on Wednesday.
If you are hoping it proves big Al wrong, don't quit your day job.

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I don't care about theory.
We really don't know much about the universe.
We might not be capable of ever understanding it.
I find outer space interesting is all.

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@sonhouse said
If you are hoping it proves big Al wrong, don't quit your day job.
I took a quick look at the article. You shouldn't read too much into the text in a URL. What the article itself is saying is that they'll be combining images from several telescopes to produce a synthetic aperture the size of the Earth. The black hole in question is Saggitarius A*, as well as another 56 Mly away - at a guess the central black hole in the Andromeda galaxy. They hope to be able to take an image of the infalling gas and so deduce the shape of the event horizon. The results will either confirm GR or refute it. This is where: "Prove Einstein wrong" in the URL comes from. This is another test of GR, and really finding an anomaly would be more interesting than not finding one.

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@chessturd said
Apparently on Wednesday they are taking a picture of a black hole. First time ever.

https://www.usatoday.com/story/news/nation/2019/04/08/black-hole-photo-what-we-see-and-how-we-see-it-einstein-wrong/3401085002/
It is still black. It isn't really a picture of the black hole itself because there is no light to see from that. I can't say I'm very impressed. Why are people making a big deal about it?

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@metal-brain said
It is still black. It isn't really a picture of the black hole itself because there is no light to see from that. I can't say I'm very impressed. Why are people making a big deal about it?
It's an interesting photo. It's always been difficult for me to imagine a black hole existing in 3 dimensional space, sucking in all matter trapped within its gravitational sphere, but here it is.

Very impressive.

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@wolfe63 said
It's an interesting photo. It's always been difficult for me to imagine a black hole existing in 3 dimensional space, sucking in all matter trapped within its gravitational sphere, but here it is.

Very impressive.
I could imagine it. Unless it can help us detect black holes better it is of no use. I'm not impressed, but that is just me.

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@metal-brain said
I could imagine it. Unless it can help us detect black holes better it is of no use. I'm not impressed, but that is just me.
What do you mean 'unless'? We just did a big deal in resolving one. That is an excellent first step on the way to fully understanding these beasts.

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@sonhouse said
What do you mean 'unless'? We just did a big deal in resolving one. That is an excellent first step on the way to fully understanding these beasts.
Resolving what? Understanding what? It is just a picture.

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@metal-brain said
Resolving what? Understanding what? It is just a picture.
The radio telescopes involved are scattered around the planet and they use a technique called 'aperture synthesis' where they record the signals from all those scopes, and using a supercomputer to put all the images together as if it were a radio telescope the size of the whole planet. The resolution part is like seeing a pebble on the moon, or hundreds of times the resolving power of Hubble. The BH is 50 million light years away so it is a pretty big deal to get an image at all.

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@sonhouse said
The radio telescopes involved are scattered around the planet and they use a technique called 'aperture synthesis' where they record the signals from all those scopes, and using a supercomputer to put all the images together as if it were a radio telescope the size of the whole planet. The resolution part is like seeing a pebble on the moon, or hundreds of times the resolvin ...[text shortened]... of Hubble. The BH is 50 million light years away so it is a pretty big deal to get an image at all.
So what? It is still black as expected. I didn't need a picture to know that. The media hype about it is more interesting. It got you impressed over nothing.

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@metal-brain said
So what? It is still black as expected. I didn't need a picture to know that. The media hype about it is more interesting. It got you impressed over nothing.
From a scientific point of view it gives us a direct measurement of the radius of the event horizon. We can then compare that with the mass as deduced from the orbits of nearby stars and check that:

r = 2GM/c^2.

What I don't see is how aperture synthesis is new since synthetic aperture radar is a well established technique.

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@deepthought said
From a scientific point of view it gives us a direct measurement of the radius of the event horizon. We can then compare that with the mass as deduced from the orbits of nearby stars and check that:

r = 2GM/c^2.

What I don't see is how aperture synthesis is new since synthetic aperture radar is a well established technique.
It is new in the sense of the number of scopes used, giving a planet wide scope for resolution purposes. Of course not for total gathering area, that is the sum of the area of the 7 scopes.