We have just seen the first image of a black hole, the supermassive black hole in the galaxy M87 with a mass 6.5 billion times that of our sun. But what is that image really showing us?
This is an awesome paper on the topic by J.P. Luminet:
Image of a spherical black hole with thin accretion disk
Astronomy and Astrophysics, vol. 75, no. 1-2, May 1979, p. 228-235
Using my every day intuition I wondered: will we see the “shadow” of the black hole even if we’re looking edge on at the accretion disk? The answer is yes because the black hole warps space-time, so even if we wouldn’t normally be able to see the back of the accretion disk, we can in this case because its light is bent up and over the black hole. Similarly we can see light from the bottom of the back of the accretion disk because it’s bent under the bottom of the black hole. Plus there are additional images from light that does a half turn around the black hole leading to the inner rings.
What about the black hole “shadow” itself? Well initially I thought it can’t be an image of the event horizon because it’s so much bigger (2.6 times bigger). But if you trace back the rays, you find that for every point in the shadow, there is a corresponding ray that traces back to the event horizon. So in fact from our one observing location, we see all sides of the event horizon simultaneously! In fact infinitely many of these images, accounting for the virtually infinite number of times a photon can orbit the black hole before falling in. The edge of the shadow is due to the photon sphere – the radius at which light goes around in closed orbits. If a light ray coming in at an oblique angle just skims the photon sphere and then travels on to our telescopes, that is the closest ‘impact parameter’ possible, and it occurs at sqrt(27)/2*r_s
Huge thanks to:
Prof. Geraint Lewis
University of Sydney
Like him, I’m hoping (predicting?) we’ll see some moving images of black holes tomorrow
Prof. Rana Adhikari
Caltech
Riccardo Antonelli – for excellent images of black holes, simulations and ray-tracing code, check out:
The Event Horizon Telescope Collaboration
Check out their resources and get your local link for the livestream here:
Special thanks to Patreon supporters:
Donal Botkin, Michael Krugman, Ron Neal, Stan Presolski, Terrance Shepherd, Penward Rhyme
Filming by Raquel Nuno
Animation by Maria Raykova
source: https://paddlewithsim.com
Xem thêm các bài viết về Du Lịch: https://paddlewithsim.com/category/du-lich/
OK, just over an hour to go! This is the link to the Washington DC National Science Foundation livestream: https://ve42.co/NSFstream
Click here for links to other live streams (there are several available in different countries): https://ve42.co/EHTstream
gotta love some youtubers
Awesome 👏
I think I got it but just in case… can you say that all again please?
Hi, very nice explanation. I have some questions, are the black holes 3D objects? What we see if we are in the back, same if we are in "front"?
Holy that was 5 months ago wow i felt like this was a month ago
Charlie Day explains black holes
Why here is an accretion disk and not an accretion sphere?
🙋🏻♂️ Hello Derrick, I have a question I'd love you to explain! I understand that the gravity past the event horizon of a black hole is so strong that nothing, not even light, can escape it. But in the 70s, Stephen Hawking theorised that black holes radiate energy, until they finally evaporate, by way of quantum processes ("Hawking Radiation"). I'm not a physicist, and to me these two ideas seem contradictory. Radiation would have to be massless, like light, or have mass, like all other fundamental quantum particles, so how can energy in any form escape the singularity's gravity? Could you please do a video about Hawking's Radiation?
I though it would have been your obsession for longer than a week
이해해버렸다!!
I know I'm kinda late but, if we could look at that thin line of light underneath or above the event horizon, the light particles that nearly are captured but released from it's gravity, could we not zoom in far enough on that ring of light to see our past under the right circumstances? (Distance being a huge obstacle)
please can you Add the Arabic language to the translation i will be greatful ✌
veralevel. Tamilguys hit the like
soooooo if my wife is sucking m,y cock and we get sucked into a black hole……………will i cum??
Now i can see what i see! Thank you!
3:28 Spiral out… KEEP GOING!
👎Тошнило от рекламы перед роликом, но от самого ролика стошнило на много обильнее… хорош фуфло тюхать
I couldn't understand the complexity even when explained… but let me feel like I've understood it
its fake
Wow, I was doing a research paper on black holes and I started at a paragraph, but this video made my paper almost an entire paper long! Thank you for this! ^^
아~ 무슨 소리인지 모르겠네~ ^^
But how Cooper comes out of black hole in interstellar . ??
How can a black hole keep light from escaping since the speed of light is constant and has no mass to be pulled in? Please explain.
7:33 INTERSTELLAR BLACK HOLE
My theory is that we are inside a black sphere right now!😯😵
Merci.
Ur great Teacher. Well done brother i subscribe you for furthur info
As always you respect your viewers by giving the best possible explanation. Thanks.
As always you respect your viewers by giving the best possible explanation. Thanks.
As always you respect your viewers by giving the best possible explanation. Thanks.
허수세상에 에누마엘리쉬가어딨냐 ㅋ 생겨봐야
생물상태로 0차원에 갇히고싶냐?ㅋ
Hello. You stated that light could not escape the immense pull of the black hole, but you also stated that it could escape orbit and shoot out into infinity. Could you please clarify?
Почему название на русском, а видео нет?
Почему ролик называется по русски а я при этом нихуя не понимаю о чём речь?
i think the lecturer of this video got high enough, because his eyes are red
What are you saying man?
Einstein in heaven said: do you believe me now?