What is a Black Hole? -- Black Holes Explained

  • Published on Sep 28, 2015
  • BREAKING NEWS: First image of a Black Hole captured by the Event Horizon Telescope!
    If you're looking for a video to explain Black Holes to kids, we recommend this excellent video from Socratica Kids: bit.ly/BlackHoles4Kids
    Black Holes are super dense regions of space. They have such immense gravity that anything close by is sucked in, never to escape. Even LIGHT! That's why we call the BLACK HOLES.
    Some black holes are small. Some are HUGE! There are stellar black holes, about the size of a dozen of our suns. Then there are SUPERMASSIVE black holes, that are the size of MILLIONS and MILLIONS of our suns! Scientists think there are supermassive black holes in the center of each galaxy. The supermassive black hole in the center of our Milky Way galaxy is called Sagittarius A. Recently, the Event Horizon Telescope was able to image the supermassive black hole in the center of the distant galaxy Messier 87. This black hole is known as M87, and was the first black hole ever to be imaged using the giant radio telescope EHT.
    In this video, we talk about how Black Holes are formed and how we can detect them using various methods.
    You can jump to chapters in our video here:
    1:03 History of Black Holes
    1:49 Theory of Relativity by Einstein - Spacetime
    3:12 Are black holes real?
    3:48 Finding black holes
    4:13 Binary Stars
    4:54 Schwarzschild Radius and the Event Horizon
    5:24 Finding the mass of a black hole
    5:56 Stellar and supermassive black holes
    6:44 Angular momentum
    7:37 The Ergosphere
    8:09 Electric Charge of a black hole
    8:42 No Hair Theorem
    9:04 Inside a black hole
    10:09 Current research topics
    We highly recommend the Astronomy textbook “Universe” by Roger Freedman et al:
    Universe 9th Edition amzn.to/2so6Ums
    Universe 10th Edition amzn.to/2tfBjUe
    Shop Amazon Used Textbooks - Save up to 90%
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    Hosted by Liliana de Castro
    Written and Produced by Kimberly Hatch Harrison & Michael Harrison
    #BlackHoles #Astronomy #EventHorizon

Comments • 591

  • Socratica
    Socratica  9 months ago +13

    If you're looking for a video to explain Black Holes to kids, we recommend this excellent video from Socratica Kids: bit.ly/BlackHoles4Kids

  • Leafgreen1976
    Leafgreen1976 Day ago

    I'd honestly stay and watch this video if she was talking about dirt.

  • Harry Chen
    Harry Chen 2 days ago

    I watched this video over and over again and I have no idea what it is about.
    I am NOT ALONE.

  • X borg Genesis
    X borg Genesis 9 days ago

    Its that means we gonna die

  • rguimatorres
    rguimatorres 9 days ago

    What if black holes also can’t let anything get in?

  • zapfanzapfan
    zapfanzapfan 13 days ago +1

    "Billions and billions" that Carl actually didn't say. I think it was Johnny Carson who used it when imitation Carl and it stuck. I'm glad that the solar sail that Carl talked about on the Tonight Show 40 years ago now has actually flown.

  • cjhyde78
    cjhyde78 13 days ago


  • cjhyde78
    cjhyde78 13 days ago

    But correct me if I'm wrong that black holes bend time and space so the size is skewed?

  • Brainstorming Plus
    Brainstorming Plus 18 days ago


  • Micheal Bay
    Micheal Bay 21 day ago

    Channels like this are hidden gems on TheXvid, like opals and corals under the sea

  • Ashmeed Mohammed
    Ashmeed Mohammed 23 days ago

    this was like reading a physics text, im hooked!!

  • Alex Kumar
    Alex Kumar 24 days ago

    House is gravity force overcomes strong forces? Gravitation force is considered to very smaller than strong force

  • Aahia Dhanus
    Aahia Dhanus 26 days ago

    I am very much interested to cosmology .. I love that subject more than my GF .... That's why I stay single... ... But I am enjoying my moments... Any way u try to make on what is theory of relativity./ Time dilation

  • Duality
    Duality 27 days ago

    who are you and why am i just now finding this??

  • Matheus Santos
    Matheus Santos 27 days ago

    Janete dos -Mutantes-

  • Adil Bougma
    Adil Bougma Month ago

    is that true that when you get inside the black hole you can see you self in the past or the future

  • Scottie Clevinger
    Scottie Clevinger Month ago

    You’re so beautiful

  • Dilan Weerasekara
    Dilan Weerasekara Month ago

    This is really cool.

  • Some One
    Some One Month ago

    A star does not burn anything. Burning is an oxidation reaction, while stars, as you mentioned, use nuclear fusion.

  • E Dog
    E Dog Month ago +2

    6:07 is her favorite

  • Neil Watkins
    Neil Watkins 2 months ago

    I bet a Blackhawk could escape a big Black Hole......or maybe not.

  • dikshark Kakoti
    dikshark Kakoti 2 months ago

    I love space especially black hole so I want to study astronomy so I love the way you explain it thanks you even for it I have subscribed it😋

  • Musa Matt
    Musa Matt 2 months ago

    Thanks u so much

  • Brad Allison
    Brad Allison 2 months ago

    You really makes these concepts easy to understand.

  • skyeplus
    skyeplus 2 months ago

    Small omission: after the explosion the remnant becomes a compact star, either a white dwarf or a neutron star. If a neutron star is massive enough it becomes more compact than it's event horizon radius, forming a black hole. Also, black hole doesn't act like vacuum cleaner, it acts like any regular massive object, unless you're too close.

  • David Johnston
    David Johnston 2 months ago

    Very informative

  • Tom Baker
    Tom Baker 3 months ago

    I TOTALLY respect her brains and definitely agree with her interest.....I hope she would not be offended for also thinking she's got to be the most beautiful teachers of Astronomical Physics I've ever seen.

  • Ergo Laude
    Ergo Laude 3 months ago

    Would be cool to see this updated with the picture, since we have now seen one.

  • Anushka
    Anushka 3 months ago

    Please post a video about moon

  • daniel thomass
    daniel thomass 3 months ago

    is the cor of a star an or planet the same as a black hols singularity ?

  • Muhammad Junaid Ali
    Muhammad Junaid Ali 3 months ago


  • Dys Pater
    Dys Pater 3 months ago

    Good vid. Just an FYI - in Latin the "c" is hard (pronounced like a "k") so it's pronounced "Prin-KIP-ee-yah"

  • Brainstorming Plus
    Brainstorming Plus 3 months ago


  • Leafgreen1976
    Leafgreen1976 3 months ago

    I'd watch you on StarTrek

  • Ritesh Chaudhary
    Ritesh Chaudhary 4 months ago

    what will happen if a black hole looses its net charge and become neutral??

  • john noe
    john noe 4 months ago

    Hey, I subscribed to this channel and it didn't create a teeny tiny black hole. I want my money back ! Oh wait, ...it was free.

  • john noe
    john noe 4 months ago

    Hah, I love it when she says, "The surface of the sphere is called the event horizon, if anything crosses the event horizon it's gone forever - hidden from the rest of the universe." Just look at her eyes as she says this. To be fair, this is the meat and potatoes of a black hole and it does deserve to be dramatized.

  • Gerardo Moscatelli
    Gerardo Moscatelli 4 months ago

    If school teachers and journalists could just start by explaining this simple concept : black hole = massive star with escape velocity > C. Thank you so much !

  • Pongo 1998
    Pongo 1998 4 months ago

    I have a question mam.

  • Undertaker
    Undertaker 4 months ago

    ooh! her expressions😍

  • Sewoniku Oluwafemi
    Sewoniku Oluwafemi 4 months ago

    A black hole 🕳️ is a shadow of the of it object.

  • TeamAllGamers 6969
    TeamAllGamers 6969 4 months ago +1

    So are blackholes spherical or one dimensional?

  • Atul Dwivedi
    Atul Dwivedi 4 months ago +1

    A pair of little... cute.. black holes...ur eyesss...
    👍👍Very Good explanation

  • Drew Phillips
    Drew Phillips 4 months ago

    Liliana de Castro is 40 years old. Amazing.

  • Josh C
    Josh C 4 months ago

    Black holes stink

  • I'm just saying
    I'm just saying 4 months ago

    Disclaimer: most if not all in this video are opinions (some call it theory) not fact.
    I don't know how long into the future, but we will all look back and laugh that the entire world actually think this is fact.

  • Alberto Álvarez
    Alberto Álvarez 4 months ago

    Having stars instead of eyes and pure light instead of a smile makes her the most expert person on the subject. I wonder where she hides her wings... Video post-processing maybe?

  • Alberto Álvarez
    Alberto Álvarez 4 months ago

    Tener estrellas en lugar de ojos y luz pura en lugar de una sonrisa la convierte en la persona más experta en el tema. Me pregunto dónde esconde sus alas ... ¿Posprocesamiento de video tal vez?

  • Macam2macam
    Macam2macam 5 months ago

    but black hole spew things too right ms socratica? at the quasar. i think that s the way out from black hole.

  • nadenitza
    nadenitza 5 months ago

    I can listen to her all day :D

  • richar Muñico Samaniego


  • Ben Dunselman
    Ben Dunselman 5 months ago

    Pronounciation of Schwartzschild should be like thexvid.com/video/7NsM4dmqbSc/video.html. Not as in 'child'.

  • Bent Mathiesen
    Bent Mathiesen 6 months ago

    I have always found the term "black hole" misleading. "Black Star" would be better in my opinion.

  • Ronald de Rooij
    Ronald de Rooij 6 months ago

    I subbed! But.... I still have two criticisms. The first is not important, but please research how to pronounce Scharzschild correctly. The second is more important. The most defining thing of a black hole is that is sucks up future in spacetime. If you enter, all of your possible futures are inside the black hole. It is not only (or primarily) that you cannot get enough speed to exit a black hole, although that is true. But primarily, the black hole will not give you a future outside it anymore. That is the "time" component of spacetime is completely reversed with the "space" component. Thereby leaving a "hole" in spacetime. The name "black hole" is therefore not badly chosen.

    KEEGAN AntoNY 7 months ago

    I believe some black holes maybe super intelligent civilizations that have learned to harness nearly 100% energy from stars around them without getting themselves destroyed... no need to move around and conquer if you are advanced... Bring all the energy to yourself by bending space and even time maybe through gravitational waves. I mean, Possible 100,000 black holes in the milky way? That answers the Femi paradox hypothesis that there should be thousands of alien civilizations in this galaxy yet we cant see them. Think about it.

  • Vishal Mishra
    Vishal Mishra 7 months ago

    Does Newton's law of gravitation apply to light photons assuming their mass as being equivalent to their energy (mc^2 = E = h𝜈 for each photon) ? Or does General Relativity deviate in spite of this assumption.

  • Nick Mitri
    Nick Mitri 7 months ago

    In this video, you say stars ultimately blow up into a super nova then turn into black holes.
    But in THIS video
    you say they turn into WHITE DWARF STARS.
    Does it become a black hole or a white dwarf?

    • SuperGalaxyElise
      SuperGalaxyElise Month ago

      Depends on the mass of the star theres actually 3 objects that form when a star dies a white dwarf or a neutron star or a black hole. our sun for example is a medium size star it will turn into a red gigant then slowly turn into a planetary nebula and then the collapse will turn into a white dwarf. heavy stars explode in a supernova now what happens to the core depends on how much mass the star had if the star has 15 to 10 solar masses the core will collapse into a neutron star if the star has 20 to 25 solar masses it will collapse into a black hole sorry if i was 6 months late

  • maui waui
    maui waui 7 months ago

    balls of burning gas? collapsing under gravity? how does space-time curvature compresses a ball of gas?

  • Sérgio
    Sérgio 7 months ago


  • ✨연탄🐶
    ✨연탄🐶 7 months ago

    Now we know black hole exist because of the picture we recently got that showed a massive black hole from the Messier galaxy