Unveiling the first-ever image of a black hole [video]
411–420 of 525 posts
Re: Unveiling the first-ever image of a black hole [video]
#412Earlier quoted context omitted.
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.
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 fuzzin…
He isn't explaining why the blackhole would look like a fuzzy coffee mug stain. He's explaining why the _picture_ of the blackhole will look like a fuzzy coffee mug stain.
To your point, it's like taking a picture of Uranus with film and waiting for it to develop. People familiar with the matter can guess what the _image_ will look like not what Uranus actually looks like.
This is all very clear in the first 25 seconds of the video if you actually listen to what he's saying.
Re: Unveiling the first-ever image of a black hole [video]
#413Earlier quoted context omitted.
As far as I know, Veritasium and others occasionally join efforts and coordinate around soon to be published scientific discoveries in a goal to increase exposure. Don’t know if this was the case with the black hole image.
It probably wasn't coordinated, because he got the black hole that was being imaged wrong. He said we would see a picture of Sagittarius A*, but we actually got the black hole at the center of M87.
They observed both, watch the follow-up: https://www.youtube.com/watch?v=S_GVbuddri8
"The Event Horizon Telescope Collaboration observed the supermassive black holes at the center of M87 and our Milky Way galaxy (SgrA*) finding the dark central shadow in accordance with General Relativity, further demonstrating the power of this 100 year-old theory."
Re: Unveiling the first-ever image of a black hole [video]
#414Earlier quoted context omitted.
As far as I know, Veritasium and others occasionally join efforts and coordinate around soon to be published scientific discoveries in a goal to increase exposure. Don’t know if this was the case with the black hole image.
It probably wasn't coordinated, because he got the black hole that was being imaged wrong. He said we would see a picture of Sagittarius A*, but we actually got the black hole at the center of M87.
I thought we got both, which is the best possible outcome: no one is wrong and there are more black hole photos.
Re: Unveiling the first-ever image of a black hole [video]
#415Is black hole a 3D object like a sun? If so, I assume the light in the event horizon cover the whole object, i mean 3D shaped as well. How the picture taken from the telescope shown the dark area where the black hole is located? I mean, shouldn’t the whole black hole covered by the light thus we can’t see the black hole?
The black hole itself is spherical, but the light we're seeing around it isn't projected by the event horizon; rather, it's light from behind/around the black hole that isn't blocked. This video explains in much more detail: https://www.youtube.com/watch?v=zUyH3XhpLTo
But if it's spherical, should not the light be all around it?
Re: Unveiling the first-ever image of a black hole [video]
#416Earlier quoted context omitted.
A rephrasing: How does the gravity-information about what's inside the event horizon get out?
That's a really interesting question. (And you did say "graviton particles or gravity waves" in your first post, and I missed that.) At first glance, I think that the gravity information can't escape from inside the event horizon, just like light can't. That means that the event horizon describes a frozen version of the mass inside it, not a current "live" version. And that seems to work, if you think about gravity w…
It’s not that interesting unfortunately, although I liked your approach. A graviton would be just another boson like a photon, and like a photon would be unable to escape. All of the worldlines of a graviton within the event horizon would lead to a collision with th singularity. It’s just another aspect of “No Hair” on the hole.
Remember that this applies everything where r≤1. As far as “flat” worldlines I think you might be thinking of a geodesic approaching r=1 in terms of a null geodesic, which isn’t necessarily true unless we’re dealing with a photon or graviton. Regions I,II of the Classic Kruskal-Szekeres extension illustrates this pretty clearly.
https://en.m.wikipedia.org/wiki/Kruskal–Szekeres_coordinates...
The total mass of the black hole (and all other information possible about it) can be described in terms of the boundary at r=1, so there’s no problem with mergers or accretion. To answer Wallace’s original question, we see no information escaping the black hole. What we’re seeing is sort of like shining a light on an absence of information, and observing the shadow cast. That’s not quite right, but it’s close.
Re: Unveiling the first-ever image of a black hole [video]
#417Earlier quoted context omitted.
The video JumpCrisscross shared above says this is the black hole at the center of our galaxy, so why isn't its accretion disk oriented the same as the rest of the galaxy? Isn't that weird?
It's actually in a galaxy called Messier 87 which is 55 million lightyears away.
The observed both supermassive black holes at the center of M87 and our Milky Way galaxy Sagittarius A
Re: Unveiling the first-ever image of a black hole [video]
#418Earlier quoted context omitted.
> "What? You obviously didn't read what I wrote. Are you ok?" You're ranting about Saturn and Jupiter for some reason. Why don't you calm down and look at page eight of the paper that Veritasium video was based on: https://ve42.co/luminet "Image of a spherical black hole with thin accretion disk Astronomy and Astrophysics, vol. 75, no. 1-2, May 1979, p. 228-235" Look at that last image, and squint at it until it gets…
Really awesome link, thanks for that! It's always interesting to see theory that is decades out in front of experimental confirmation, and then proves to be dead right.
Yeah, I did a double-take when I saw that was published in 1979. I think that's really cool.
Re: Unveiling the first-ever image of a black hole [video]
#419Good video that correctly predicted the image and describes why it looks the way it does [1]. TL; DR The dark area is the entire surface of the event horizon, including the side facing away from us, plus some more due to photons missing the event horizon "directly" being drawn in. One side is brighter due to its being Doppler boosted. [1] https://www.youtube.com/watch?v=zUyH3XhpLTo
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!
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_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.
Re: Unveiling the first-ever image of a black hole [video]
#420Earlier quoted context omitted.
the original tiff is 7416x4320 it's still too many pixel, it can be a fifth of that while conveying the same amount of information. I'm puzzled by this, if each of those pixel is actually captured by the lenses, why is it all this much uniform? was it smoothed or does this suggest that it's actually a gigantic uniform cloud of gas? haven't seen the whole video of the release, I'll have to catch up later in the evenin…
From the press conference, they said that the raw captured data took up 6 cubic meters of hard drives
> cubic meters of hard drives
Astronomy and high energy physics are pretty much the only science I know where this is an applicable unit of measurement