• Question: Hi, I’ve been looking at the black hole photo recently and I’ve been wondering something. It’s that surely rather than activity just on the side of the black hole, there would be activity behind and in front of it, therefore making us unable to see the black abyss which is in the photo. If any of you can explain this I’d be really grateful. Thanks!

    Asked by anon-220967 on 21 Jun 2019.
    • Photo: David Wilson

      David Wilson answered on 21 Jun 2019:

      Is it this photo?
      .

      .
      Your absolutely right that there must be something going on on the other sides of it but not only are they really difficult things to see because they don’t emit or reflect any light but also we can only look at them from Earth which only gives us one perspective.
      .
      The story about how they managed to photograph the black hole is really interesting.
      .
      https://www.jpl.nasa.gov/edu/news/2019/4/19/how-scientists-captured-the-first-image-of-a-black-hole/
      .
      They needed to use a network of telescopes all over the earth called the Event Horizon Telescope to create a super telescope that had an aperture (the bit of a camera that lets light in) as wide as the Earth itself. The Bigger the aperture the more light can enter the camera.
      .
      Also, because a black hole doesn’t emit or reflect light the Event Horizon Telescope was looking for how light behaved around the area we thought the black hole was.

    • Photo: Matthew Bareford

      Matthew Bareford answered on 21 Jun 2019:

      this is a very good question…

      Essentially, the image you see is not actually a photograph in the usual sense, but an image created by combining data from multiple telescopes.

      The image shows a silhouette of the hole against the surrounding glow of the event horizon, all of the matter being pulled into the hole. At the centre of the black hole is a gravitational singularity, where all matter is crushed into an infinitely small space.

      Due to the nature of the black hole, ANYTHING past the event horizon cannot escape it’s gravitational pull, even light. Thus we cannot see anything infront/behind it, as no light is escaping for us to see it. Rather, all we can see is the absence of light – what is depicted as the ‘black hole’.

      the ring we can see around the outside in the image, is the light that is escaping before the event horizon, which will extend all around the black hole.

      here is the real mind melting bit the black hole isn’t actually a hole, but a single point in space (singularity) where matter is condensed. what people observe as the ‘hole’ is actually a disc around that point, which is constantly spinning/swirling in a single plane… hence, nothing in front or behind

    • Photo: Rebecca Moon

      Rebecca Moon answered on 21 Jun 2019:

      Sorry, space is not my expertise. Looks like David and Matthew have some suggestions though.

    • Photo: Kaitlin Wade

      Kaitlin Wade answered on 21 Jun 2019:

      Love that photo so much. David and Matthew have answered way better than I could ever so I’ll defer to them 🙂

    • Photo: Nina Rzechorzek

      Nina Rzechorzek answered on 21 Jun 2019:

      Great answers above – I have nothing to add as this is not my area of expertise. Fab question though! 🙂

    • Photo: Thiloka Ratnaike

      Thiloka Ratnaike answered on 24 Jun 2019:

      I am reading the answers with much interest…

Comments

  • Photo: anon-220967

    anon-220967 commented on :

    Thanks, and yes that is the photo David. Just in case I’ve made a mistake Matt, the black area we see is condensed matter in the shape of a disc that is spinning very fast? Ok, I’ve got another question (sorry if I’m getting a bit tiring), but I asked a question on here about a year ago, and apparently the forces in a black hole are so strong that they pull apart atoms and cause constant nuclear explosions. So how could the disc exist? Is it because it destroys the shells in atoms and causes a much more condensed form of matter, or is it something else? Again, I’d really appreciate it if you answered. Thanks agiain!

  • Photo: Matthew

    Matthew commented on :

    That is an excellent observation, and as far as I can understand this is all to do with the Black holes rotation. the black hole is formed from the collapse of a rotating star, this then creates a rotating black hole. Because of the centripetal force (the force of spinning around) the black hole actually bulges out at its equator, and this means it is not spherical, but more disc-like. remember not even light can escape a black hole. Thus the speeds at which it is spinning are faster than the speed of light, meaning that this centripetal force is so strong, that the black hole is compressed even more in terms of thickness (I hope that makes sense). this then causes the gas and debris around the black hole to form the ‘accretion’ disc we can see in so many of the iconic pictures of the black hole.

    There are atoms smashing together and ripping apart and explosions, all happening in the accretion disc. We can see the x-rays and gamma rays produced by these being released into space but once this all gets past the event horizon, any further activity is impossible to see…

    I hope this answers your question… if you have any further follow ups, then happy to try and help 😊👍