1. Black holes

2. A little bit of history At the beginning, searchers and especially Newton studied the nature of light; the speed of the light was known and the liberation speed too and the question was: Is it possible for an object to be so massive that his liberation speed is faster than the speed of light ?

3. 1783 John Mitchell exposed his theory which consists in putting the sun or anover massive object into a small sphere.

4. He concluded by saying that If an object comes from very far in the direction of the sphere when it passes the surface of the sphere, its speed will be faster than the speed of light.

5. 1785 The french mathematicien Laplace calculated the very small radius about 6 kilometers such an object would have if it was as massive as our sun

6. Most famously black holes where predicted by Einstein’s theory of general relativity, when a massive star dies it leaves behinds a small, dense remnant core 1915

7. 1916 The german astronomer Schwarzchild showed that a massive object squeezed to a single point would warp space around it so much that even the light could’nt escape.

8. 1967 Physicist John Wheeler used the term « black hole » to describe them in a public lecture, a name that has stuck ever since.

9. 1994 Hubble Space Telescope

10. Today definition A black hole is a massive star in the last phase of his evolution, in which the star collapses creating a volume of space-time with a gravitational field.

11. The black hole is so dense that it creates a pit deep enough to prevent light from escaping.

12. Black holes in movies

14. Websites: https://www.nasa.gov https://www.sciencenews.org https://en.wikipedia.org/wiki/ https://www.aps.org/publications/apsnews/201 412/thorne.cfm http://zidbits.com

15. END