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Ok, wait a second. I liked a lot of this video, but there are some aspects which are kind of ridiculous. He says his reason for his confidence in this predictio

Ok, wait a second. I liked a lot of this video, but there are some aspects which are kind of ridiculous. He says his reason for his confidence in this prediction is "I think it's going to look like a fuzzy coffee mug stain." He doesn't give an actual reason. He does talk a lot about theory, a lot of it interesting and novel to me, but by the end of the video, most of this theory suggests a different-looking image!

bdamm 8y ago
The entire video is his description of the reasons for why it'll look like a fuzzy coffee mug stain. It's "fuzzy" because of the low resolution, not because the black hole itself is fuzzy. Undoubtedly there will be work to improve the best quality photograph of a black hole, now that we have one at all.
- wallace_f 8y ago
  That's not correct. Around 25% of the video is discussion around the concept of the radius of photon sphere to the event horizon, and what constitutes the light surrounding the photon sphere (one explanation he gives is that there are infinite reflections). Then he spends the last 30% of the video talking about reflections of the acretion disk. This is the theory that he never included in his original prediction, but doesn't explain why he made that call.
  - bdamm 8y ago
    Uh.. It's the reason that the "shadow" is larger than the Schwarzschild radius. He's describing the ratio of the "rim" to the "hole". So while the picture may be fuzzy, there's information in it anyway about what the pictures means relative to how large/spin we think the black hole is. In fact I wish he'd said more about the Doppler effect.
    - wallace_f 8y ago
      Ok I mean, now what you're writing, that's not even wrong. The black part of the image being larger than the actual radius of the blackhole is a discussion about the relative size of the black area you see in the image, to the actual black hole itself. I think that should make sense to you? It's not an argument about why he predicts it will look like a "fuzzy coffee stain," as opposed to other simulated images. Are you able to see the difference between those two ideas? I think you have some other discussion you were having confused with this one. To remind you about your earlier comment, you stated disagreement with me, saying this video was him only talking about why he predicted the image to look like a "fuzzy coffee stain" as opposed to some other simulated and theorized predicgions. I think the above paragraph and reply should obviously show you why this is actually not true. Are you still with me? I do think most of the video is interesting, but he never states an argument about why he chose that prediction. That was what I thought was ridiculous. Science is about reason and evidence, not just saying "believe me." Maybe you watched a different video? You should watch this video, the last 30% talks about simulations done in which the acretion disk reflects around the black hole, he uses example images which look a bit different!
      - darkpuma 8y ago
        The reason for the fuzziness should be obvious. It's really far away and it's really hard to see. Expecting a jump from "never seen before" to "seen in amazing visual clarity" is unrealistic.
        wallace_f 8y ago
        That's also not even wrong. You can't see why? Let's say we're imagining what Uranus would look like. I draw a picture, and say it should look like a "fuzzy Jupter." But you ask, why should it look that way? Do you have a reason? And I say you should be confident, but don't provide an argument. By the end, I start talking about how it might look like Saturn. Then I come along and say, "it should be obvious the fuzziness is because it is far away." That final statement is not even wrong. It misses the point.
        8y ago
coldtea 8y ago
>He says his reason for his confidence in this prediction is "I think it's going to look like a fuzzy coffee mug stain." He doesn't give an actual reason. He doesn't need to give a reason. The reasons why it would look like a "fuzzy coffee mug stain" are well known since Hawkings...
acqq 8y ago
How about forgetting that video for a moment and trying to consider the following picture: https://static.projects.iq.harvard.edu/files/styles/os_files_xxlarge/public/eht/files/unnamed-2.png https://static.projects.iq.harvard.edu/files/styles/os_files... Taken from here: https://eventhorizontelescope.org/science https://eventhorizontelescope.org/science (the official site of the project). On the left is how it would look like if we weren't so far -- we are 55 million light years far from that. You know the distance from us to our Sun, which you see on the sky but can cover with your own thumb? That object is 3,500,000,000,000 times farther than the Sun is far from us. On the right is what we can reconstruct from the signals measured because we are so far and we have "only" the telescope the size of the Earth. More details would be visible (the picture would look more like the one on the left) either if we had even much bigger telescope than the Earth, or if the black hole of the same size were much closer to us, which it is not.
manigandham 8y ago
Did you see the movie Interstellar? He included it in his video. That's what the black hole looks like, except with the relativistic beaming make one side brighter than the other. Here's the image from the movie: https://www.wired.com/wp-content/uploads/2014/10/ut_interstellarOpener_f.png https://www.wired.com/wp-content/uploads/2014/10/ut_interste... Now imagine that image being taken far away by several ground-based telescopes put together at the edge of their capabilities and using math to error correct and stitch together the final result. What you get is what we saw.
- wallace_f 8y ago
  Ah, sure. Also, if you go to the EHT's own website, they have a gallery of predicted, simulated images. Here is another prediction: https://www.sciencemag.org/news/2019/04/here-s-what-scientists-think-black-hole-looks https://www.sciencemag.org/news/2019/04/here-s-what-scientis... I just wanted to know why he went with that one because his prediction was really accurate. And I thought him saying 'just trust me' was bad form. He did talk some about this, but he didn't really say anything about why he thought his illustration would be so accurate compared to a lot of other stuff seen in the press. I dont care (or have any idea why) how many downvotes or insults I get. It is a perfectly reasonable question and criticism.
  - manigandham 8y ago
    I don't see the difference, the predictions are the same. The only changes in the image depend on what angle the black hole is being viewed at which would influence whether we see a band across the middle and the slimmer inner ring.
    - wallace_f 8y ago
      Lol the image I linked is obviously very different. There is some groupthink going on here affecting people like you and others. The above is obviously plain.
      - 8y ago

bdamm 8y ago

The entire video is his description of the reasons for why it'll look like a fuzzy coffee mug stain. It's "fuzzy" because of the low resolution, not because the black hole itself is fuzzy. Undoubtedly there will be work to improve the best quality photograph of a black hole, now that we have one at all.

wallace_f 8y ago
That's not correct. Around 25% of the video is discussion around the concept of the radius of photon sphere to the event horizon, and what constitutes the light surrounding the photon sphere (one explanation he gives is that there are infinite reflections). Then he spends the last 30% of the video talking about reflections of the acretion disk. This is the theory that he never included in his original prediction, but doesn't explain why he made that call.
- bdamm 8y ago
  Uh.. It's the reason that the "shadow" is larger than the Schwarzschild radius. He's describing the ratio of the "rim" to the "hole". So while the picture may be fuzzy, there's information in it anyway about what the pictures means relative to how large/spin we think the black hole is. In fact I wish he'd said more about the Doppler effect.
  - wallace_f 8y ago
    Ok I mean, now what you're writing, that's not even wrong. The black part of the image being larger than the actual radius of the blackhole is a discussion about the relative size of the black area you see in the image, to the actual black hole itself. I think that should make sense to you? It's not an argument about why he predicts it will look like a "fuzzy coffee stain," as opposed to other simulated images. Are you able to see the difference between those two ideas? I think you have some other discussion you were having confused with this one. To remind you about your earlier comment, you stated disagreement with me, saying this video was him only talking about why he predicted the image to look like a "fuzzy coffee stain" as opposed to some other simulated and theorized predicgions. I think the above paragraph and reply should obviously show you why this is actually not true. Are you still with me? I do think most of the video is interesting, but he never states an argument about why he chose that prediction. That was what I thought was ridiculous. Science is about reason and evidence, not just saying "believe me." Maybe you watched a different video? You should watch this video, the last 30% talks about simulations done in which the acretion disk reflects around the black hole, he uses example images which look a bit different!
    - darkpuma 8y ago
      The reason for the fuzziness should be obvious. It's really far away and it's really hard to see. Expecting a jump from "never seen before" to "seen in amazing visual clarity" is unrealistic.
      - wallace_f 8y ago
        That's also not even wrong. You can't see why? Let's say we're imagining what Uranus would look like. I draw a picture, and say it should look like a "fuzzy Jupter." But you ask, why should it look that way? Do you have a reason? And I say you should be confident, but don't provide an argument. By the end, I start talking about how it might look like Saturn. Then I come along and say, "it should be obvious the fuzziness is because it is far away." That final statement is not even wrong. It misses the point.
        8y ago

coldtea 8y ago

>He says his reason for his confidence in this prediction is "I think it's going to look like a fuzzy coffee mug stain." He doesn't give an actual reason. He doesn't need to give a reason. The reasons why it would look like a "fuzzy coffee mug stain" are well known since Hawkings...

acqq 8y ago

How about forgetting that video for a moment and trying to consider the following picture: https://static.projects.iq.harvard.edu/files/styles/os_files_xxlarge/public/eht/files/unnamed-2.png https://static.projects.iq.harvard.edu/files/styles/os_files... Taken from here: https://eventhorizontelescope.org/science https://eventhorizontelescope.org/science (the official site of the project). On the left is how it would look like if we weren't so far -- we are 55 million light years far from that. You know the distance from us to our Sun, which you see on the sky but can cover with your own thumb? That object is 3,500,000,000,000 times farther than the Sun is far from us. On the right is what we can reconstruct from the signals measured because we are so far and we have "only" the telescope the size of the Earth. More details would be visible (the picture would look more like the one on the left) either if we had even much bigger telescope than the Earth, or if the black hole of the same size were much closer to us, which it is not.

manigandham 8y ago

Did you see the movie Interstellar? He included it in his video. That's what the black hole looks like, except with the relativistic beaming make one side brighter than the other. Here's the image from the movie: https://www.wired.com/wp-content/uploads/2014/10/ut_interstellarOpener_f.png https://www.wired.com/wp-content/uploads/2014/10/ut_interste... Now imagine that image being taken far away by several ground-based telescopes put together at the edge of their capabilities and using math to error correct and stitch together the final result. What you get is what we saw.

wallace_f 8y ago
Ah, sure. Also, if you go to the EHT's own website, they have a gallery of predicted, simulated images. Here is another prediction: https://www.sciencemag.org/news/2019/04/here-s-what-scientists-think-black-hole-looks https://www.sciencemag.org/news/2019/04/here-s-what-scientis... I just wanted to know why he went with that one because his prediction was really accurate. And I thought him saying 'just trust me' was bad form. He did talk some about this, but he didn't really say anything about why he thought his illustration would be so accurate compared to a lot of other stuff seen in the press. I dont care (or have any idea why) how many downvotes or insults I get. It is a perfectly reasonable question and criticism.
- manigandham 8y ago
  I don't see the difference, the predictions are the same. The only changes in the image depend on what angle the black hole is being viewed at which would influence whether we see a band across the middle and the slimmer inner ring.
  - wallace_f 8y ago
    Lol the image I linked is obviously very different. There is some groupthink going on here affecting people like you and others. The above is obviously plain.
    - 8y ago