The universe...end and beginning...?

"The devil is in the details" (old expression)

Our Galaxy contains a central black hole; this black hole is part of the Galaxy. Therefore, the Galaxy is more massive than the black hole.

What you mean is that black holes are the densest objects in the universe (and even that might be untrue at the very small scale).

The Gravitational slope is greatest very close to black hole. However, this steepness does not extend to the entire universe.

If we were to replace the Sun with a black hole having the exact same mass as the Sun, then at the surface of this black hole (3 km from the centre, as measured from our frame of reference), the gravitational slope would be tremendous (but not infinite). However, if you move out to a distance of 696,265 km (the radius of our present Sun), the gravitational distortion of space-time AT THAT DISTANCE would be roughly the same as it is now.

At Earth's distance from the Sun (and/or black hole), it would be the same whether the black hole or the Sun is there (of course, things would quickly get colder with the black hole at the centre instead of the Sun).

So, as far as the rest of the universe is concerned, the fact that the mass of the Sun has the form of a star or the form of a black hole is irrelevant. Things will not get "sucked in" any faster. The one difference is that anything that does fall in will never come back out.

Any two masses in the universe (including any two black holes) already attract each other. They don't have to wait until all other matter ceases to exist.

If the universe were completely empty except for two baseballs placed at random, they would attract each other through gravity. Of course, if placed at the same distance, baseballs would attract each other a lot less than two black holes of the same diameter (with much bigger masses).

Note that I give black holes definite sizes. That is the size of the "event horizon": the distance from the centre (as measured in our frame of reference) where the escape speed equals the speed of light.

We do not really know what goes on inside that diameter. However, we do know that time and length as we know them cannot be treated the same way. For example, if a photon is barely inside the event horizon, trying to come out, it will travel through its local space at the speed of light. However, the amount of space between it and the horizon keeps increasing a bit faster.

All that space will find itself between the photon and the centre (whatever that is). From the frame of reference (= point of view) of the photon, the distance to the centre -- behind the photon -- is increasing at the speed of light. So after a year, the distance to the centre has increased by at least one light year.

But for us, observing from the outside, if the radius was 3 km to begin with, and if no new mass enters the event horizon, it is still 3 km after one year. The size of the black hole (as measured from the outside) has not changed, but its size measured from just inside is increasing faster than the speed of light.

Yes, it is weird. It get even weirder when we actually study the math that should help us understand...

This brings us to the problem of expansion. Space itself is expanding. The further away things are, the faster space grows between them. And it seems that the expansion is itself accelerating.

So if your two final black holes are far enough apart, it is possible that their gravitational attraction will not be enough to bring them together.

If they are brought together, then they will merge into one.

Is there a finite amount of mass in the universe? Maybe not. There is a finite amount in the (finite) "visible universe" meaning the portion we can see.

However, it is possible that the universe is infinite. In which case a finite amount of mass would leave us with a density of zero (clearly not the case). Therefore, if the universe is infinite in spatial extent, then the quantity of mass must also be infinite.

Since we do not fully understand what happens inside the event horizon, then it is possible that whatever happens inside could produce a new universe. However, this new universe would be stuck inside the event horizon, as far as we (in the old universe, outside the black hole) are concerned. This would not be a problem: as we saw earlier, the limited size of a black hole (from our frame of reference) does not prevent the "inside" from being much bigger. Big enough for a new universe? why not.

But we do not know.

The idea of black holes being massive hence has very strong gravity, actually contradicts basic physics principles. Mass is defined as something that occupies space and has weight. A black hole on the other hand is said to be a singularity hence it does not have volume. So how can a black hole be massive if it does not have the volumetric component which characterizes mass? A cosmology based on black holes or a black hole therefore may not be tenable.

The universe expands because matter is continuously being created at least at this time. When energy in the form of electromagnetic radiation interacts with dark matter, particles are created in pairs like the creation of an electron and a positron. Thus an addition volume of space is also created which is occupied by the anti-particle. The addition of volume causes the universe to expand. When almost all the dark matter would have been converted to physical masses by the process of pair production, the expansion will slow down and eventually come to stop. Then gravity takes over. The masses will pull each other, matter and anti- matter wil be dawn closer to each other until they annihilate each other and release the energy and dark matter that created them. But the released energies will trigger another round of pair production process on the dark matter and the cycle is repeated.

If you wish to have a more thorough discussion on this, give me your e-mail address and I will send you my articles on the process of creation and the expansion of the universe.

the universe will end in one of two ways (theoretically anyways....)

1. big crunch... everything comes flying back in like a rubber band, which some think will give birth to another big bang and everything will begin again (this isn't new thinking either.... amazingly enough this theory is found amongst more then one ancient culture)

2. big stretch [or freeze]... whatever is driving the expansion of the universe has enough monementum to keep going indefinately.... this is a much longer and prolonged ending, but an ending nonetheless..... eventually most stars will die, then their bigger brothers, the ones who give birth to black holes, will die as well, and by now the universe has become extremely cold, nearly all life (if not all) will be gone just for this remaining fact... if you could look out in space and see them, you'd see a bunch of black[er] spots in the sky, but even they die eventually as the uinverse continues it's expansion, eventually molecules would be ripped apart, and even after that the atoms that make molecules will be ripped apart until the universe becomes nothing but a giant mesh of sub-atomic (or smaller) particles just floating around aimlessly.....

black holes need to feed on matter or they dissipate... so yes the black holes will devour the matter around us, but no more then they do now (although matter will disappear faster into black holes because there will be more black holes in this existence...) eventually (actually not long after the universe 'begins to die') there wont' be enough matter for them to suck up around them (matter neeeds to be close, they can't suck it cross-galactically) and they will die...

i know of a particullarly intresting documentary on all this, if you'd like a link, email me and i will find it.

"edit: slipknot, thank you for the educated response. The thing that has me wondering, however, is this: assume there are only 2 black holes left in the universe...will their sheer mass - since each theoretically contains half of all known matter - make the gravity between them absolute and irresistible? I guess what I am asking is: do black holes have mass themselves?"

relatively quickly (in terms of the universes life atelast) there will come a point where they eat less matter then they dissipate.... even the most massive will disappear before long. they do have mass, but they need to feed to sustain their life.....

best way i can put it is think of a candle, that candle has a wick which says it has a definate end, and it has a life span.... unless something lengthens that wick (in this case, being able to feed) that wick will burn out....does that help?

also a black hole couldn't eat another to extend it's life.... all that would happen is the 'hole' would merge with another and grow.... just like with a star (theoretically since this can't yet be proven) the bigger it is, the quicker it goes..... if it was to 'eat' or merge with another, it would effectively shorten it's life span...

the chances of the two meeting in all of the unverse (considering the expansion is constant and we're talking trillions of years...)

there's just nex to 0 chance...

i really hope this helps, if not email me and i can further try to answer your question.... of all astronomy i have a very good understanding of black holes... they started as science fiction and are the center of many aspects of it... so starting with black holes (IMO) is the starting of understanding the universe in general.....

i had that thought and logiclly thats the way i would have guessed it(the big bang) happened. it also makes sense because we know that things seem to work in cycles. therefore the universe too should cycle its self. but i saw a picture of a black hole and it kinda confused me. it showed the black hole eating the matter and then spitting it out once it had "eaten it" this made sense to me too cause it would eat out information and then we wouldnt know weather it got spit out or not. but it said the amount it spit out increased and decreased depending on how much or how little it ate. so if black holes dont suck it in and hold it but rather eat it and digest it like our stomaches. eating the energy and then spitting out the useless remains. i dont see how the cycle theory could work. but it also is a cycle. like eating a banana, then breaking it apart in our stomaches and then we get rid of the remains, but those remains are still useful and can still be used. like using manure for soil. so im still kinda lost on this one lol. but our theory makes so much sense doesnt it! i love it.

stay is evil backwards, ahh hell clones stay tissue inseminated as Kyton reported, it purposes the question fairly is whilst human beings are human and not purely the cells they are made out of, Charles Manson complained that the choose and jury of his path ate meat and hence the place as responsible of homicide as he became, besides the shown fact that actual, the jury proved his factor and the choose symbolically murdered him with the demise penalty, which he relatively escaped from. Ethics is a question based on the herd of conformity, what habit is appropriate to the race is often in line with whim. So basing it on my whim, clones are existence.

Actually that sounds fairly plausible and quite well argued.