Mountains Piano Chord

Computer Architecture: A Quantitative Approach, David Patterson









"To understand what a black hole, let's start with a star like the sun The sun is 1,390,000 kilometers in diameter and a mass 330,000 times greater than Earth's. Taking into account the mass and distance from the surface to center show that any object placed on the surface of the Sun would be subjected to a gravitational pull 28 times Earth's gravity on the surface. Star power

retains its normal size thanks to the balance between a high core temperature, which tends to expand the star substance, and the huge gravitational pull, which tends to contract and squeeze dry.

If at any time the temperature drops, gravity will be master of the situation.



The star begins to contract and throughout the process inside the atomic structure disintegrates. Instead of atoms will now electrons, protons and neutrons loose. The star continues to contract until the mutual repulsion of electrons counteracts any further contraction.

The star is now a "white dwarf." If a star like the Sun suffered the collapse that leads to the white dwarf state, all its mass would be reduced to an area of \u200b\u200babout 16,000 kilometers in diameter, and surface gravity (with the same mass but to a much smaller distance from the center) would be 210,000 times that of Earth.



Under certain conditions the gravitational pull becomes too strong to be counterbalanced by the electronic repulsion. The star contracts again, forcing the electrons and protons combined to form neutrons and also forcing the latter to clump together in close contact. The neutron structure counteracts any further contraction and then what we have is a "neutron star", which could accommodate the entire mass of our Sun into a sphere only 16 kilometers in diameter. The surface gravity would be 210,000,000,000 times greater than Earth's.



Under certain conditions, gravity can overcome even the strength of the neutron structure. In this case there is nothing that can oppose the collapse. The star can shrink to zero volume and surface gravity increase towards infinity.

According to the theory of relativity, the light emitted by a star loses some of its energy to move against the gravitational field of the star. The stronger the field, the greater the loss of energy, which has been proven experimentally in space and in the laboratory.

The light emitted by an ordinary star like the Sun lose very little energy. Emitted by a white dwarf, a little more, and that emitted by a neutron star even more. Throughout the process of collapse of the neutron star comes a time when the light emanating from the surface loses all its energy and can not escape.

An object under higher compression than that of neutron stars would have a gravitational field so intense that anything approaching it would be trapped and could not get out. It is as if the object had fallen trapped in a infinitely deep hole and never cease not falling. And since not even light can escape, the compressed object is black. Literally, a "black hole".



Today astronomers are looking for evidence of the existence of black holes in different places the universe. "



ISAAC ASIMOV