Science Forum

Science Forum

  1. Subscriberchessturdonline
    Trump 2020
    Joined
    20 Mar '19
    Moves
    4190
    09 Apr '19 03:09
    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/
  2. Subscriberchessturdonline
    Trump 2020
    Joined
    20 Mar '19
    Moves
    4190
    09 Apr '19 04:00
    Picture already taken.
    They are releasing it on Wednesday.
  3. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
    Moves
    52856
    09 Apr '19 21:23
    @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.
  4. Subscriberchessturdonline
    Trump 2020
    Joined
    20 Mar '19
    Moves
    4190
    09 Apr '19 21:35
    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.
  5. Standard memberDeepThought
    Losing the Thread
    Cosmopolis
    Joined
    27 Oct '04
    Moves
    80056
    09 Apr '19 22:12
    @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.
  6. Joined
    07 Dec '05
    Moves
    14766
    11 Apr '19 13:17
    @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?
  7. SubscriberWOLFE63
    Tra il dire e il far
    C'e di mezzo il mar!
    Joined
    06 Nov '15
    Moves
    22232
    11 Apr '19 13:41
    @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.
  8. Joined
    07 Dec '05
    Moves
    14766
    11 Apr '19 15:48
    @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.
  9. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
    Moves
    52856
    12 Apr '19 14:54
    @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.
  10. Joined
    07 Dec '05
    Moves
    14766
    12 Apr '19 15:19
    @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.
  11. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
    Moves
    52856
    12 Apr '19 15:59
    @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.
  12. Joined
    07 Dec '05
    Moves
    14766
    13 Apr '19 01:55
    @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.
  13. Standard memberDeepThought
    Losing the Thread
    Cosmopolis
    Joined
    27 Oct '04
    Moves
    80056
    13 Apr '19 12:17
    @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.
  14. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
    Joined
    28 Dec '04
    Moves
    52856
    13 Apr '19 14:22
    @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.
Back to Top