Quote:
Originally Posted by xelasnave
You have avoided comment on the possibility of there being a proposition that the matter we belive will form a black hole can in fact collapse to that degree. alex
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Okay Alex, sourced from publicly accessible websites, here is a current and educated discussion on Black Holes, without the Math
By definition a black hole is a region where matter collapses to infinite density, and where, as a result, the curvature of spacetime is extreme. Moreover, the intense gravitational field of the black hole prevents any light or other electromagnetic radiation from escaping. But where lies the "point of no return" at which any matter or energy is doomed to disappear from the visible universe?
Applying the Einstein Field Equations to collapsing stars, German astrophysicist Kurt Schwarzschild deduced the critical radius for a given mass at which matter would collapse into an infinitely dense state known as a singularity. For a black hole whose mass equals 10 suns, this radius is about 30 kilometers or 19 miles, which translates into a critical circumference of 189 kilometers or 118 miles.
If you envision the simplest three-dimensional geometry for a black hole, that is a sphere (known as a Schwarzschild black hole), the black hole's surface is known as the event horizon. Behind this horizon, the inward pull of gravity is overwhelming and no information about the black hole's interior can escape to the outer universe.
At the center of a black hole lies the singularity, where matter is crushed to infinite density, the pull of gravity is infinitely strong, and spacetime has infinite curvature. Here it's no longer meaningful to speak of space and time, much less spacetime. Jumbled up at the singularity, space and time cease to exist as we know them.
Newton and Einstein may have looked at the universe very differently, but they would have agreed on one thing: all physical laws are inherently bound up with a coherent fabric of space and time.
At the singularity, though, the laws of physics, including General Relativity, break down. Enter the strange world of quantum gravity. In this bizzare realm in which space and time are broken apart, cause and effect cannot be unraveled. Even today, there is no satisfactory theory for what happens at and beyond the singularity.
What happens to a black hole after it forms? Does it vibrate? Radiate? Lose mass? Grow? Shrink?
Partial solutions of the Einstein equations point to two possible outcomes:- A non-rotating, spherically symmetric black hole, first postulated by Schwarzschild.
- A rotating, spherical black hole, predicted in 1964 by the New Zealand mathematician Roy Kerr.
These two types of black holes have become known as Schwarzschild and Kerr black holes, respectively. Both types of black holes are "stationary" in that they do not change in time, unless they are disturbed in some way. As such, they are among the simple st objects known in General Relativity. They can be completely described in terms of just 2 numbers: their mass M and their angular momentum J. Theoretically, black holes may also possess electric charge, Q, but it would quickly attract enough charge of the opposite sign. The net result is that any "realistic" or astrophysical black hole would tend to exhibit zero charge. This simplicity of black holes is summed up in the saying "black holes have no hair," meaning that, apart from its mass and momentum, there is no other characteristic (or "hair") that a black hole can exhibit.
However, both the Schwarzschild and Kerr black holes represent end states. Their formation may result from various processes, all of them quite complicated. When a "real" black hole forms from, say, the collapse of a very mass ive star, or when a black hole is disturbed by, say, another black hole spiralling into it, the resulting dynamics cause disturbances in spacetime that should lead to the generation of gravitational waves.
By numerically solving the Einstein equations on powerful computers, scientists have been able to simulate the gravitational waves emitted by perturbed or interacting black holes. When visualized in movies generated by advan ced computer graphics, the unfolding wave patterns are not only intriguing but strikingly beautiful. By emitting gravitational waves, non-stationary black holes lose energy, eventually become stationary and cease to radiate in this manner. In other words, they "decay" into stationary black holes, namely holes that are perfectly spherical or whose rotatio n is perfectly uniform. According to Einstein's Theory of General Relativity, such objects cannot emit gravitational waves.
Though we cannot "see" a black hole itself (since not even light can escape the hole's gravitational field), we may see the hole's effects on nearby matter. For example, if gas from a nearby star were sucked towards the black hole, the intense gravitational energy would heat the gas to millions of degrees. The resulting X-ray emissions could point to the presence of the black hole.
Or, if a massive black hole were surrounded by large amounts of orbiting material -- gas, dust, even stars -- their rapid motion close to the hole could be observable via shifts in the energy of the radiation they emit. Evidence along these lines is mounting, suggesting that black holes may not be that rare in the universe.
However, such evidence remains indirect and therefore inconclusive. To confirm that black holes actually exist, we'll need to be able to observe the gravitational waves they produce as they form or interact.
If scientists could build
gravitational wave detectors of sufficient sensitivity, they should be able to measure the vibrations in spacetime generated by black holes as they form from a collapsing star, when they ingest large amounts of matter, or if they interact, even collide with a second black hole or another massive object, such as a neutron star. Certain patterns of gravitational waves emitted would reveal the "smoking gun."
So far, the wavelike disturbances in spacetime have eluded detection. In a relativistic universe, there should be no shortage of places in which to hunt for black holes. Much larger and more sensitive detectors are now under construction. With luck, soon gravitation scientists may be shouting "Eureka!"
So it's up to you whether or not to believe in the existence of black holes, I for one firmly believe in the probability they exist, unless you can furnish me proof they do not.