351–360 of 525 posts
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Makes sense. So I guess they could probably tell us an upper bound on how bright it is.
Indeed! That’s for sure: it’s probably not hard to extract a bound on the magnitude of a part of the spectrum from this analysis.
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The collecting time is important, but mainly to 1) sample the rotation of the Earth in the Fourier space for better angular resolution and 2) for raising your overall signal-to-noise ratio is the image (but the one released is already pretty good, so not much improvement can be done there unless you're trying to go for the faint features in the image). Unfortunately, you can only do interferometry with simultaneous m…
Thanks. We seem to need a big radiotelescope on the moon then? That should give simultaneous measurement on a much larger baseline?
Problem is, you would want to have several Gigahertz of (radio) bandwidth. You are not going to down link that raw, but rather as a number of channels, integrated over a number of microseconds and digitized at something between 4 and 64 samples per bit, but we are still talking a down link data rate of gigabits per second.
Previous work on this was done for the movie Interstellar. The resolution of the rendering software was so high that team members were able to examine the black hole very closely - Because Gargantua was spinning at almost the speed of light, the rendering showed that spacetime warped into shapes never seen before. This led to the publication of —> https://arxiv.org/abs/1502.03808 Kip Thorne describes his work not thi…
> Kip’s description of black holes here is also fascinating: https://youtu.be/oj1AfkPQa6M — first time I learnt what “warped” space-time means :) In this video he makes a comment which I struggle to fully understand: He says that ALL of the matter which belonged to the cooled-off star is DESTROYED in the process of creating a black hole. That concept of complete destruction eludes me. I assume what he means is, the m…
As to what physically happens to the stuff once it's inside, I don't know if we know for certain. It gets dragged towards the center. From the point of view of the rest of the universe, it might never actually reach the singularity: GR would make it look like it's going slower and slower and slower.
Speculation about what is actually inside the event horizon is at most mathematical extrapolation, since we can't actually crack one open and look.
The papers with the scientific details are here (open access): https://iopscience.iop.org/journal/2041-8205/page/Focus_on_E... Article in physics world with comparisons to simulations: https://physicsworld.com/a/first-images-of-a-black-hole-unve... "AskScience" AMA on Reddit about the breakthrough: https://www.reddit.com/r/askscience/comments/bbknik/askscien...
From reddit: >"Hi, regarding the image itself: What I don't understand is why does it look like a donut and not a bright sphere? Assuming the black hole is actually spherical and not disc shaped, I would expect the Halo to be spherical and surrounding the black hole? so all we would see would be the ball of bright gas, even though there is a black hole in the middle?" This is also what I would have expected.
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What? You obviously didn't read what I wrote.
> "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…
I think you are literally not even reading my comments. Either that, or you are going through some personal issues right now.
I think it might help you if you tried to first understand that I am not complaining about the image being fuzzy. I have no idea why you keep going back to that. I spelled out an analogy to explain this to you and you got angry and insulting.
Are you really sure you are ok? You clearly have something going on.
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Wow, the video you posted is even more informative and clear than the actual press conference, and it was created by someone who hadn't even seen the image yet based purely on the mathematical predictions of what we would see. Kind of sad that after all the amazing effort and resources that have gone into the creating the image that the international team couldn't have featured an explanation as clear as this in thei…
The video by Veritasium is by a guy who literally got a PHD on the subject of making physics more approachable through videos. He is exactly the person I would expect to provide a more clear and understandable explanation. https://www.youtube.com/watch?v=S1tFT4smd6E&feature=youtu.be...
Good 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
Part I: https://www.youtube.com/watch?v=VnJYo6LKzgA
Part II: https://www.youtube.com/watch?v=Nlry6LqWwJ0
Peace
International collaboration on scientific projects (International space station, CERN) always fills me with hope and optimism for humanity. It's a nice contrast to opening the papers and reading the regular news, dominated by politics, with all the pessimism that creates. Hooray for science.
If I understand it, this class of “telescope” is made up of arrays of telescopes spread as widely over the hemisphere as possible. We can only get data like this by collaborating with as many different sites as possible. It literally can’t exist without broad support from many countries. As one of the scientists said in the interview, the next step is a telescope bigger than the earth. Hopefully we can collaborate on…
It doesn't sound like they just snapped a picture. The one guy says they used "supercomputers" for 6 months to get the image. Sunspots look black relative to the rest of the sun but are actually very bright. Could this be the same thing? How did they set the black level? Is there a description of the procedure somewhere? EDIT: Found the paper describing the data processing: https://iopscience.iop.org/article/10.3847/…
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> "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…
It's really strange that you are unable to understand such a simple complaint I made, even after going to extra effort to spell it out. You even have even become aggressive insulting. I understand that some people become that way when they get confused, but how is it possible you are confused here? I think you are literally not even reading my comments. Either that, or you are going through some personal issues right…