blackholes form when really fucking big stars get really old and fusion stops working (once they start making iron fusion causes a loss of energy = bad) they collapse on themselves and become super dense


escape velocity > speed of light = cant see them / interact with them = theres no reason to discuss the nature of the matter because for all intents and purposes it has been removed from the universe

looks nasty.

well matter is typically all the same. they are different types like protons electrons and neutrons and several more particles but like 09 said a black hole is when a star is so large that when it stops fusion the gravitational pull is larger than the "resistance" of a neutron. the entire core of the star is nearly instantly hit with all the matter rushing in that it rebounds (like a small car going full speed at a deisel truck. the car gets demolished and flys off in a direction). this is what the superova is. all the loose matter of the sun hits the core and due to newtons third law the core hits back and sends it flying in all directions.

now after that happens, the protons in the molecules of the remant star undergo a rapid type of decay in which a proton emits a positron (the antimatter counterpart of an electron) and becomes a neutron, and transforms the star it into a neutron star. once this occurs it becomes a hunk of neutrons that is incredibely dense. so dense that a tablespoon of it weighs tons. this is because it is as dense as a nucleus of an atom all the around because there are no more electrons creating the epmty space between atoms

now a black hole is formed when the gravity is even stronger, and the force required to "squish" a neutron cannot withstand the gravity. think of a bucket of apples, where each apple is a neutron and although they dont repel each other, it is still extremely difficult to compress them simply because the force required to compress the apple. likewise, it takes ENORMOUS forces to collapes a neutron. this is what happens to a black hole; the matter itself is collapsed into an infinitasmally small point. so in theory, black holes take up no space at all. instead the "size" of black holes are measured by their gravitational pull and therefor the mass that theyve accumulated

black holes are ex-stars that had enough mass to collapse on itself (their gravitational pull was stronger than their internal pressure). to understand the degree taht things are compacted: inside a black hole earth would be the size of a thumbnail.

there is always another theory tho. some dont believe stars can form black holes, they believe the black holes formed when the universe was younger and denser. that they formed from gas and dust just like any star -they call these possibilities primordial black holes.

small in diameter maybe, but gigantic in mass.

This post was edited by juliusjuice on Mar 29 2009 04:11pm

or a super dense neutron star.

Also... Jazz... he is right, blackhole's are about as close to nothing as you can get. absolutely nothing, is more than what a blackhole is.

atleast... in Volume. The idea of a black hole is to be a near singularity, like the bigbang... If we re-enter a matter dominate universe, and we come into "Crunch" theroy, all the universe will be sucked into itself and re-create the big-bang singularity. Blackholes would be a major part of this.


and Kami, your wrong... Gravitational pull is infinite... just arbitrary, it never reaches zero, in some way shape and form, your being effected by the gravitational pull of everything in the universe.

Actually, first off, nothing ever enters a black hole, its impossible and would take ammounts of time that are just so Huge that you could never even possibly imagine it.

The earth would actually string out, like a noodle, impossibly thin, and long. Time would effect the matter differently and would cause dilation effect. this would mean, as i said, no matter would ever cross the event horizon of a blackhole. (atleast, as far as we can understand it.)

with how quantum physics and mechanics works... we really cant do anything but guess... because its impossible to observe.

You have to remember though... that those really fucking big star's... dont go into Iron fusion, they create the heavier elements.

uhm, no. the gravitational pull up until the event horizon is infinite. but the pull itself is not. once its past the event horizon the gravitational pull is just as normal as anything else. otherwise one black hole would be the size of the universe, which is obviously not the case
and ive never heard any theories of neutron stars being the center of galaxies either.

question... do plum bobs work in space? for finding the relative center of gravitation of the particular location?

that is a hot debate topic among cosmologists. i believe black holes grow by eating mass, some believe the mass never passes the event horizon. some believe black holes "decay" over time. they emit colossal amounts of x-rays from their poles, therefore if they do not eat any more mass, their density decreases until something similar to a super nova happens. i dont believe this at all, i think they grow and grow in mass.

other than the x-ray/gamma ray emmisions we can only see the accretion disc around the black hole (matter that has not passed the event horizon). measuring its red shift we can detect the velocity of spin a black hole has. the fastest yet found was like 96 rps. -pretty amazing that something with 20 solar masses can spin that fast -that amount of energy is unfathomable to me.