• Question: Hi, I was wondering what is a black hole and also how are scientists sure that it exists?

    Asked by louloulorna to Akram, David, Gill, Jack, laurenceharwood on 16 Mar 2012.
    • Photo: Jack Snape

      Jack Snape answered on 16 Mar 2012:

      Good question! 🙂 A black hole is a dead star that is so heavy that light cannot escape from it… that’s why it is ‘black’ !

      First of all… black holes were predicted by Einsteins theory of relativity before we saw one. Since then we used huge telescopes to look deep into the galaxy. Scientists saw some stars moving around in a weird way. Because of gravity, it looked like they were orbiting (moving around) something really massive… but that massive thing wasn’t shining or giving out any light!! So we think that is a black hole – it matched up with Einstein’s theory very well.

      Hope that answers it 🙂

    • Photo: Akram Alomainy

      Akram Alomainy answered on 16 Mar 2012:

      It did for me Jack 🙂

    • Photo: Laurence Harwood

      Laurence Harwood answered on 19 Mar 2012:

      Yep!!! A star so dense, not even light can escape its gravity.

    • Photo: Gill Menzies

      Gill Menzies answered on 19 Mar 2012:

      I’ll leave this to Laurence and Jack – really not my field, but interesting ….