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  • We all know that Stephen Hawking has worked on some of the biggest questions about our cosmos.

  • But what are those ideas?

  • What's at the centre of a black hole?

  • Black holes are incredibly dense objects with such strong gravity that nothing, not even light, can escape their pull.

  • Hawking worked with physicist Roger Penrose to show that if you were able to travel to the centre of a black hole, you'd find something called a 'singularity'.

  • In a singularity, so much matter is squashed into such a small space that the force of gravity becomes infinite.

  • Everything is crushed into a point of infinite density, punching a hole through the fabric of the universe, and tearing up the rulebook of physics as we know it.

  • It's pretty frightening stuff.

  • What happens at the edge of a black hole?

  • You might think that a vacuum is empty.

  • But it's not. At least, not according to quantum theory.

  • It's fizzing with particles and anti-particles that pop into existence from nowhere and then disappear.

  • When this happens at the edge of a black hole, one of the pair of particles can fall in, leaving the other to escape.

  • This tiny stream of escaping particles is known as, ''Hawking radiation.''

  • Now, those particles that fell into the black hole, they have a negative mass, and cause the black hole to get smaller, and smaller, until it disappears.

  • It will take a while, in fact a very long while, but in its final moments a black hole will explode with the energy of a million nuclear bombsleaving nothing behind.

  • So why is Stephen Hawking our most famous living scientist?

  • Well, he showed that at one point everything in our universe was squeezed into a singularity, which then exploded into the Big Bang, eventually forming galaxies, stars, planets, you, me, and everything in existence!

  • That was the beginning of our universe.

  • And I suppose the incredible thing is that he came up with all these profound, provocative insights without the convenience of being able to write anything down.

  • He did it all by thought alone.

We all know that Stephen Hawking has worked on some of the biggest questions about our cosmos.

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Stephen Hawking's big ideas... made simple | Guardian Animations

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    Johnny Tsai posted on 2020/09/07
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