How to Take a Picture of a Black Hole | SciShow News

How to Take a Picture of a Black Hole | SciShow News

[ ♪ Intro ] On April 10th, 2019 the world saw, for the
first time ever, visual confirmation that black holes actually
exist. Technically, up until now they only existed
in theory. We were pretty sure they were there based on stuff like stars with weird orbits at the center of our galaxy, and really strong radio
and other electromagnetic signals coming from really small points in space. But we never actually saw one. Which is why it made such a big splash when
researchers released this image of M87*, the supermassive black hole at the center of the
galaxy M87, 55 million light years away from Earth. It’s all thanks to the Event Horizon Telescope,
or EHT, a collaboration of over 200 individuals spanning 13 institutions and the globe. Last week, they published their findings in
six papers in The Astrophysical Journal Letters. In this now famous fuzzy photo, we can’t
actually see the black hole of course. Or, rather, its event horizon, the final point
of no return for light and matter. The black shadowy blob at the center is actually
about 2.5 times bigger than the event horizon. That’s as close as the laws of physics will
let us get. Turns out it’s hard to take a picture of something
that light cannot escape from. Now to snap this picture, we needed a telescope with a resolution of 2,500 times better than
the Hubble Space Telescope. In astronomy, angular resolution refers to
the ability to see two objects that appear close together in space
as their own distinct sources. But it really just comes down to how much
detail you get in to an image. And there are really only two ways to improve
it. One is to study light that has a shorter wavelength. The other is to make your telescope bigger,
specifically, increase its collection area, or the size of whatever it uses to collect
light. Radio waves are really the best waves to use
for studying supermassive black holes, because that’s where they, or rather, the material
around them, emit most of their light. Also, longer wavelength light does better
at penetrating all that gas and dust between us and what we’re trying to look at. So to study a black hole like this, astronomers are interested in radio wavelengths of about 1 millimeter. But there’s a catch. At those wavelengths, the telescope you need
to resolve a black hole would have to be, like, as big as a planet. So the EHT collaboration came up with one. They turned the entire Earth into a telescope. Now, just ‘cause you didn’t notice any
construction in your particular backyard, that doesn’t mean it didn’t happen. Here’s a weird thing about telescopes: you
can take a bunch of small ones, spread them out, and get computers to link them all up, and pretend to have a telescope that’s as big as the distance between them. And this actually works. You get gaps in the images, but the same amount
of resolution. This technique is called interferometry. Say you have two telescope dishes spaced a
kilometer apart. They’re both pointed at the same target
in the sky. Light coming from that source is going to
hit the two at slightly different times, but if you have super accurate clocks to keep
track of that, you can combine the two signals. The light waves from the two telescopes will
interfere with one another, like ripples from two different sources in a pond. But with some sophisticated computer programs,
you can use that interference to generate an image. And suddenly, it’s like you had one dish
a kilometer across. The more telescopes you have, the more complex
it gets, but the better your image will be. To create the EHT, astronomers had to upgrade,
link, and synchronize eight pre-existing telescopes around the world, from Hawai’i to Spain to Antarctica. They collected petabytes worth of data, which
was flown on hard drives to supercomputers in the US and Germany to be processed into
a picture. Which requires the programs not to just stitch
together separate images, but eliminate all the noise coming from stuff that’s not the black hole, and then to fill in all the gaps due to us not having a single telescope dish
the size of a planet. Filling in those gaps is kind of like inferring
the melody of a well-known song when you can only hear some of the notes. But it might be difficult to narrow it down
to just one song. Like, maybe it’s “Under Pressure” or
maybe it’s “Ice Ice Baby.” That’s why EHT didn’t produce just one
image. Initially, there were actually four. Four separate teams worked independently from
one another to produce the first images to avoid potential bias. They used two different classes of algorithms,
but in the end they all came out relatively the same. Most importantly, you can see the shadow in
the middle of all of them. That proved their techniques were working. After some more refinement, the now-famous final image was made by averaging three different processing methods. And the Internet, rightly, went wild. We are, like, way late to this party. Sorry. Now in the future, there are several ways
to improve images like these. One is to simply look at the object for longer. The collaboration observed M87* over 4 nights,
between 7 and 25 times each night, collecting data for just three to seven minutes apiece. Another is to collect data at other wavelengths
of light, which will require upgraded technology with faster processing speeds. We could also add in more telescopes, as well
as add ones that have larger collecting dishes. Which EHT is working on. Naturally, astronomers want to apply this
method to study other supermassive black holes. Like Sagittarius A*, the strong radio source
at the center of our galaxy, the Milky Way. It’s also about a thousand times less massive
than M87*, but way, way closer. But it’s hiding behind a lot of stuff that
will interfere with the signal we receive, which future observations will need to account
for. The first ever black hole picture took the
internet by storm. But when you understand how much work went into making it, and how many talented scientists were involved, and how they turned our planet into a telescope? It only gets cooler. Thanks for watching this episode of
SciShow Space News, which we couldn’t make without the support of our patrons. If you like what we do here, and you’re
interested in being a part of it, check out [ ♪ Outro ]


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    SciShow Space

    Do you need more space news today? Head over to the main SciShow channel for a look at rain on the sun and the results of the NASA twin study!

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    HOTU Orbit

    I'm confused… I thought Black Holes were already confirmed to be a true thing. I've seen documentaries that talked about how scientists have observed Black Holes eating stars many years ago. Black Holes are invisible, but when they eat something, we can infer their existence.

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    They only observed M87 over 4 nights? The hell? Then what's this 2 year wait all about? If it's just data analysis, they need better equipment.

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    Mich ael

    What we should do is put a bunch of space telescopes on escape trajectories from the sun, then we can have a continuously growing telescope for better and better images.

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    Couldn't we use Earth's orbit as the size of the virtual telescope by taking images over the course of a year?

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    could you put radio telescopes on other planets and sync them? thus making a telescope the size of the distance between the planets?

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    Espen Bøgh

    The picture we have been given to see, seems quite contradictory to the science story of black holes we earlier  have been told fra the astronomic community. Just looking at the size of the picture that is stretching thousands or millions of miles across is different from the from the originally story of black holes where the size only was at the size og pin head even it's enormous mass and that we only would be able to see the refleksions from the black hole by its disturbance to the space due to it's mass bending space, light and planets movement.

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    Bradley welch

    Is the "sophisticated" computers used on the super computers available for us to see. Can you link me or point me to where I can view them? ty.

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    Joy L

    The processing of the data could also not have been possible without the cloud solutions applied, reducing thousands of years of computing to days.

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    Again this isnt science.that have a pic if something. Give us some idea of its magnetic and mass density ect. It could be anything. Sorry nit good enough. There just looking for more funding..

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    Mystic Ventures

    Scientists: *Takes picture of first black hole
    Humanity: Why is it so blurry?
    Scientists: *Suprised pikachu face*

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    Average Nissan Channel

    I see no difference from this picture between this and any other pictures like this released decades ago

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    Rostislav Kondratenko

    Sorry to say but you have confusion between collection area and diffraction limit. Former is about brightness, it’s a measure of how much light is collected from a dim object and distance between telescopes is not relevant. Diffraction limit is about an angular resolution and how to sort between light coming from close directions. And for that the actual distance matters as more distance let one measure angles more precisely. And the processing is not about filling gaps per se. To reconstruct an image one has to collect not just the intensity but also a phase of a light wave at each angle at each moment. And that was why there was so much data. Each telescope got an image too blurry to see the black hole. Processing was to sharpen it by combining that phase information.

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    So I had read into a little bit of what was going on with the black hole picture and of course its amazing. But I was starting to get annoyed at all of my feeds being flooded with it so I ignored most of the videos. You guys may be late to the party but you got my view because of it

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    Jeremy Byington

    Great video! If I recall correctly, in the TED Talk on this topic the young lady mentioned how difficult interferometry is when you also have to account for the rotation and revolution of Earth while you are taking the photos and THEN all you get back is a bunch of noisy data that you have to run algorithms on to isolate the black hole. What I found interesting/confusing is that she said the algorithms had many different outputs that were mathematically correct, but only one that would show the black hole images. That is what I would like to know more about because it seems like there could be some assumption made to get there. Like, I could take a recipe book with a bunch of words and make an alogrithm that pulls random words out to form a bunch of Nastrodamus predictions. How is their process any more correct? (FYI – I am not doubting them, just very interested)

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    H Koizumi

    I play a game that you get drive a space ship on VR. I managed to travel to Sagitarius A black hole. I know it's just a game but when I looked at the black hole from my cockpit, it didn't even make sense because it was all distorted. I could see front and back of the disk surrounding the black hole at the same time. If I to turn my ship around, I saw own ship from behind. It's trippy.

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    Wait, black holes are at the center of galaxies? Is that true of all galaxies? Is the extreme gravity of black holes what's necessary to form a galaxy, then, like the gravity of a star is necessary to form a solar system?

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    Lorenzo Ciani

    Before the EHT, evidence of BH existence was given also by the detection of gravitational waves by the LIGO VIRGO collaboration

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    Vilhelmo De Okcidento

    The best description of interferometry is that it's just the Double Slit Experiment in reverse.

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    Lee Bannister

    Thank you for this video. When I saw the image I was like, "Yeah so what" but to learn all the tech and collaboration behind it. Now I think its cool.

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    How to take a picture of a black hole

    You just take your pants off put the camera…. and take the picture

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    It "works" because you have humans making algorithms based on what they think it should look like making up the 90% of it they can't see. This is literally a computer generated ai picture. But lemmings will believe anything.

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    Ryben Flynn

    Meh. Except for you astrophysicists and the like it was just another Outer Space picture to the rest of us. It's just too bad that Professor Stephen Hawking died before seeing his theories proved. Oh, and Albert Einstein. He would have been thrilled.

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    Black Water

    That's why we still have people trying to debunk these sorts of claims. Every time an incredible claim like a UFO, bigfoot.ect, caught with a picture or video is always fuzzy and taken with a potato camera. XD

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    Robin Steel

    1:05 "we cant actuaslly see its event horizon" this is incorrect. the black stuff is you seeing the event horizon. the reason that it appears 2.5x bigger is because as well as seeing the entire front side, youre also seeing the backside of the event horizon due to gravitational lensing

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    Hazy A.

    Theoretically does this mean we could one day launch telescopes all over the solar system and have, like, a similar telescope the size of the solar system?

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    Denny Hiu

    Ha…. that makes me wonder… What if we use the earth revolution around the sun, and for each month we capture the signal from that black hole. Shouldn't it make the entire earth orbit into a telescope ?

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    It's ok that you're late to the party! I follow lots of science channels but I've been eagerly awaiting your take on this news!

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    Saburou Saitoh

    Black hole may be related to the division by zero. However, we obtain the results 1/0=0/0=0 in a natural sense. How will?

    The famous problems were solved as follows:

    Dear the leading person:

    How will be the below information?

    The biggest scandal:

    The typical good comment for the first draft is given by some physicist as follows:


    Here is how I see the problem with prohibition on division by zero,

    which is the biggest scandal in modern mathematics as you rightly pointed

    out (2017.10.14.08:55)


    A typical wrong idea will be given as follows:


     mathematical life is very good without division by zero (2018.2.8.21:43).

    It is nice to know that you will present your result at the Tokyo Institute of Technology. Please remember to mention Isabelle/HOL, which is a software in which x/0 = 0. This software is the result of many years of research and a millions of dollars were invested in it. If x/0 = 0 was false, all these money was for nothing.

    Right now, there is a team of mathematicians formalizing all the mathematics in Isabelle/HOL, where x/0 = 0 for all x, so this mathematical relation is the future of mathematics.

    José Manuel Rodríguez Caballero

    Added an answer

    In the proof assistant Isabelle/HOL we have x/0 = 0 for each number x. This is advantageous in order to simplify the proofs. You can download this proof assistant here:

     Nevertheless, you can use that x/0 = 0, following the rules from Isabelle/HOL and you will obtain no contradiction. Indeed, you can check this fact just downloading Isabelle/HOL:

    and copying the following code

    theory DivByZeroSatoih

    imports Complex_Main


    theorem T: ‹x/0 + 2000 = 2000› for x :: complex

    by simp


    2019/03/30 18:42 (11 時間前)

    Close the mysterious and long history of division by zero and open the new world since Aristotelēs-Euclid: 1/0=0/0=z/0= tan (pi/2)=0.


    Sangaku Journal of Mathematics (SJM) c ⃝SJMISSN 2534-9562 Volume 2 (2018), pp. 57-73 Received 20 November 2018. Published on-line 29 November 2018 web: c ⃝The Author(s) This article is published with open access1.

    Wasan Geometry and Division by Zero Calculus

    ∗Hiroshi Okumura and ∗∗Saburou Saitoh


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    D Hawthorne

    I suppose the next step will be to put up a bunch of space telescopes in the furthest possible orbit or to set up a few observatories on the moon.

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    Sir Charmander the Third

    The power of unity. I wish all countries work as one… However it is still a goal needed to be accomplish sooner or later if we want to be a space-faring civilization which hopefully i can see in my lifetime. Well… giving the circumstances we are making progress to prolonging life so…

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    Fatimah Ibrahim

    Put telescopes on the moon and some in the orbit of the moon like the legrange points.. that would make a telescope the size of half the moons orbit. The resolution would be incredible but it would be expensive and the data would be almost a nightmare to retrieve..

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    The 'picture' is an artistic rendering of compiled data. They used only data that conformed to their biases. They do the same with all dating methods – if a physical thing is expected to be millions of years old and it dates to only thousands of years old, they discard the results and say it can't be dated.

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    Black hole: I`m the best hide and seek player in the entire the universe!
    Some random homo sapient on a rock: Found ya XD
    Black hole:……………
    Some random homo sapient on a rock: u mad bro?
    Black hole: Coming for ya N!%#@

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    Master Adit

    Flat Earther: Black holes don't exist because we don't have any image of a black hole.

    Scientists: We are gonna end this man's whole career.

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    Jean-Pierre PETIT

    Is it really a black hole ? Have a look on :

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    Jake Self

    Hypothetically, could something similar be done by using images from multiple points in Earth’s orbit? In other words, could a telescope the size of Earth’s orbit be patched together using a similar method?

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    Tube Kelea

    Can the EHT algorithms be modified to observe something else other than black holes or is it a specific instrument for black holes….what I am asking is can it look at anything or only a black hole?

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    Raza Qasim

    Anybody guide me. Does it mean the black hole looked like 55 million years ago not how it looks like now since it’s 55 million light years away?

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    George Michael Sherry

    I see no mention of this in the first page or so of comments, so I'll ask. At 2:14, the text (and Hank's narration) refers to 1 mm radio waves, but 1 mm waves (according to everything I can find) are not radio waves. One source says they are barely even microwaves — they are almost infrared (right on the border). Assuming the graphic at 2:08 is in meters, it says 1 mm is inside microwave (not on the border) but nowhere near radio. Did the text/script get the wavelength wrong, or did the black hole project use microwaves, not radio waves?

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    I’m a grown ass adult, but it wasn’t until this video that I realized that telescopes aren’t just a tube with glass at the ends. I mean it makes sense because the visible light spectrum isn’t all that helpful in space exploration, but I still feel like an idiot.

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