Black Holes
As the nuclear fuel is exhausted, the outward forces of radiation diminish, allowing the gravitation to compress the star inward. The contraction of the core causes its temperature to rise and allows remaining nuclear material to be used as fuel. The star is saved from further collapse -- but only for a while.
"A Black Hole Is Born." A Black Hole Is Born. NCSA, n.d. Web. 27 Mar. 2015.
Black holes are thought to form from stars or other massive objects if and when they collapse from their own gravity to form an object whose density is infinite: in other words, a singularity. During most of a star's lifetime, nuclear fusion in the core generates electromagnetic radiation, including photons, the particles of light. This radiation exerts an outward pressure that exactly balances the inward pull of gravity caused by the star's mass.
"A Black Hole Is Born." A Black Hole Is Born. NCSA, n.d. Web. 27 Mar. 2015.
Eventually, all possible nuclear fuel is used up and the core collapses. How far it collapses, into what kind of object, and at what rate, is determined by the star's final mass and the remaining outward pressure that the burnt-up nuclear residue (largely iron) can muster. If the star is sufficiently massive or compressible, it may collapse to a black hole. If it is less massive or made of stiffer material, its fate is different: it may become a white dwarf or a neutron star.
"A Black Hole Is Born." A Black Hole Is Born. NCSA, n.d. Web. 27 Mar. 2015.
The smallest ones are known as primordial black holes. Scientists believe this type of black hole is as small as a single atom but with the mass of a large mountain.
Dunbar, Brian. "Black Holes." NASA. NASA, n.d. Web. 27 Mar. 2015.
A black hole is a region in space where the pulling force of gravity is so strong that light is not able to escape. The strong gravity occurs because matter has been pressed into a tiny space. This compression can take place at the end of a star's life. Some black holes are a result of dying stars. Because no light can escape, black holes are invisible. However, space telescopes with special instruments can help find black holes. They can observe the behavior of material and stars that are very close to black holes.
Dunbar, Brian. "Black Holes." NASA. NASA, n.d. Web. 27 Mar. 2015.
The most common type of medium-sized black holes is called "stellar." The mass of a stellar black hole can be up to 20 times greater than the mass of the sun and can fit inside a ball with a diameter of about 10 miles. Dozens of stellar mass black holes may exist within the Milky Way galaxy.
Dunbar, Brian. "Black Holes." NASA. NASA, n.d. Web. 27 Mar. 2015.
Although the term was not coined until 1967 by Princeton physicist John Wheeler, the idea of an object in space so massive and dense that light could not escape it has been around for centuries. Most famously, black holes were predicted by Einstein's theory of general relativity, which showed that when a massive star dies, it leaves behind a small, dense remnant core. If the core's mass is more than about three times the mass of the Sun, the equations showed, the force of gravity overwhelms all other forces and produces a black hole.
Erickson, Kristen. "Black Holes." N.p., n.d. Web. 27 Mar. 2015.
Scientists can't directly observe black holes with telescopes that detect x-rays, light, or other forms of electromagnetic radiation. We can, however, infer the presence of black holes and study them by detecting their effect on other matter nearby. If a black hole passes through a cloud of interstellar matter, for example, it will draw matter inward in a process known as accretion. A similar process can occur if a normal star passes close to a black hole. In this case, the black hole can tear the star apart as it pulls it toward itself. As the attracted matter accelerates and heats up, it emits x-rays that radiate into space. Recent discoveries offer some tantalizing evidence that black holes have a dramatic influence on the neighborhoods around them - emitting powerful gamma ray bursts, devouring nearby stars, and spurring the growth of new stars in some areas while stalling it in others.
Erickson, Kristen. "Black Holes." N.p., n.d. Web. 27 Mar. 2015.
Black holes have distinguishing characteristics Any two that have the same mass, charge, and angular momentum (rate of rotation) are identical.
Greene, B. The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. New York: Alfred A. Knopf, 2011. Print.
Early terms- dark stars frozen stars(extreme warping brings time to a grinding stop)
Greene, B. The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. New York: Alfred A. Knopf, 2011. Print.
Einstein thought too radical. Refused to believe that such extreme configurations of matter were anything more than mathematical manipulations.
Greene, B. The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. New York: Alfred A. Knopf, 2011. Print.
If enough mass were crammed in a small enough ball, a gravitational abyss would form. Anything close gets trapped
Greene, B. The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. New York: Alfred A. Knopf, 2011. Print.
Large Hadron Collider may produce tiny black holes in lab by packing mass (and energy) of violently colliding protons into such a minuscule volume.
Greene, B. The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. New York: Alfred A. Knopf, 2011. Print.
A black hole forms when any object reaches a certain critical density, and its gravity causes it to collapse to an almost infinitely small pinpoint. Stellar-mass black holes form when a massive star can no longer produce energy in its core. With the radiation from its nuclear reactions to keep the star "puffed up," gravity causes the core to collapse. The star's outer layers may blast away into space, or they may fall into the black hole to make it heavier. Astronomers aren't certain how supermassive black holes form. They may form from the collapse of large clouds of gas, or from the mergers of many smaller black holes, or a combination of events
How Does a Black Hole Form?" Http://blackholes.stardate.org/resources/faqs/faq.php?p=black-hole-formation. Stardate, n.d. Web. 27 Mar. 2015.
Primordial black holes are thought to have formed in the early universe, soon after the big bang. Stellar black holes form when the center of a very massive star collapses in upon itself. This collapse also causes a supernova, or an exploding star, that blasts part of the star into space. Scientists think supermassive black holes formed at the same time as the galaxy they are in. The size of the supermassive black hole is related to the size and mass of the galaxy it is in.
https://www.nasa.gov/audience/forstudents/5-8/features/what-is-a-black-hole-58.html
The largest black holes are called "supermassive." These black holes have masses greater than 1 million suns combined and would fit inside a ball with a diameter about the size of the solar system. Scientific evidence suggests that every large galaxy contains a supermassive black hole at its center. The supermassive black hole at the center of the Milky Way galaxy is called Sagittarius A. It has a mass equal to about 4 million suns and would fit inside a ball with a diameter about the size of the sun
https://www.nasa.gov/audience/forstudents/5-8/features/what-is-a-black-hole-58.html Dunbar, Brian. "Black Holes." NASA. NASA, n.d. Web. 27 Mar. 2015.
