The Chandrasekhar limit

                              The Chandrasekhar limit

                   The Indian scientist who gave black hole its limits

Subrahmanyan Chandrasekhar

 

Chandrasekhar was an Indian scientist who worked on how big a star would be and still separate itself from its own gravity after it has used up all its fuel. The idea was this: when the star becomes small, the matter particles get very near each other. But the Pauli exclusion principle says that two matter particles cannot have both the same position and the same velocity. The matter particle must therefore have very different velocities.this all makes them move away from each other, and so tends to make the star expand. A star can therefore maintain itself at a constant radius by a balance between the attraction of gravity and the repulsion that arises from the exclusion principle, just as earlier in its life the gravity was balanced by the heat. 

Chandrasekhar realized that the exclusion principle can provide. The theory of relativity limits the maximum difference in the velocities of the matter particles in the star. Got sufficient dense,the repulsion caused by the exclusion principle would be less than the attraction of gravity. Chandrasekhar calculated that a cold star of more than about one and a half times the mass of the sun would not be able to support itself against its own gravity. This mass is now as the Chandrasekhar limit. He was awarded the Nobel prize in 1983, it was at least in part, for his earlier work on the limiting mass of cold star.