- Hoop Conjecture
The Hoop Conjecture, proposed by
Kip Thorne in1972 , states that an imploding object forms ablack hole when, and only when, a circular hoop with a specific critical circumference could be placed around the object and rotated. The critical circumference is given by 2 timesPi times theSchwarzschild radius corresponding to the object'smass .Thorne calculated the effects of
gravitation on objects of different shapes (spheres, and cylinders that are infinite in one direction), and concluded that the object needed to be compressed in all three directions before gravity led to the formation of a black hole. With cylinders, theevent horizon was formed when the object could fit inside the hoop described above. The mathematics to prove the same for objects of all shapes was too difficult for him at that time, but he formulated his hypothesis as the hoop conjecture.ee also
*
General relativity References
* Thorne, Kip, "", W. W. Norton & Company; Reprint edition, January 1, 1995. ISBN 0-393-31276-3.
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