In light of recent attention brought to astronomy though movies such as Interstellar and Theory of Everything, we, here at EQNS, have decided to give a brief introduction to the mechanics and evolution of black holes.
Stellar evolution results in the formation of one of three things: white dwarfs, neutron stars, or black holes. Typically, the larger the star is during its life, the more mass it'll leave behind once it dies. Stars that fall within the Chandrasekhar limit - of roughly 1.4 times the mass of the sun - end their lives as white dwarfs, with their mass being held up through electron degeneracy pressure. Stars that are slightly larger than the Chandrasekhar limit - between 1.4 and 3 times the mass of the sun - end their lives as neutron stars, whose mass is held up through quantum degeneracy pressure. Stars any larger than roughly 3 times the mass of the sun are too massive to be held up by either electron degeneracy or quantum degeneracy pressure and collapse into a singularity that we refer to as a black hole.
Stellar evolution results in the formation of one of three things: white dwarfs, neutron stars, or black holes. Typically, the larger the star is during its life, the more mass it'll leave behind once it dies. Stars that fall within the Chandrasekhar limit - of roughly 1.4 times the mass of the sun - end their lives as white dwarfs, with their mass being held up through electron degeneracy pressure. Stars that are slightly larger than the Chandrasekhar limit - between 1.4 and 3 times the mass of the sun - end their lives as neutron stars, whose mass is held up through quantum degeneracy pressure. Stars any larger than roughly 3 times the mass of the sun are too massive to be held up by either electron degeneracy or quantum degeneracy pressure and collapse into a singularity that we refer to as a black hole.
Type of Compact StarWhite Dwarf Neutron Star Black Hole | Approximate Mass RequirementLess than 1.4 times the Mass of Sun Between 1.4 and 3 times the Mass of the Sun Over 3 times the Mass of the Sun |
Unfortunately, there are currently more questions than answers when it comes to black holes. Because of their mass and density, any light or mass that strays too close to a black hole becomes lost forever. Much like the Earth's gravitational field that keeps us from floating away into space and ensures that the moon continues to orbit the Earth, the gravitational field of a black hole swallows up everything including light. The Schwarzschild radius is defined to be the distance beyond which light and/or matter may escape the pull of a black hole. Anything closer than the Schwarzschild radius, will end up being devoured by the black hole.
The Schwarzschild radius is directly related to the mass of the black hole. The more massive the black hole, the larger the Schwarzschild radius. The equation for the Schwarzschild radius is given below:
The Schwarzschild radius is directly related to the mass of the black hole. The more massive the black hole, the larger the Schwarzschild radius. The equation for the Schwarzschild radius is given below: