if there is a black hole in the centre of all galaxies, does that mean that eventually all matter in the universe will be sucked in to these and there will be nothing left?

if there is a black hole in the centre of all galaxies, does that mean that eventually all matter in the universe will be sucked in to these and there will be nothing left?

nothing but blackholes that is. Then they will evaporate and there will just be big seas of nothingness. At least that's our current best guess.

Rather depressing but there you have it!

what about the jets of particles that shoot out from black holes when their anti particle is pulled over the event horizon? will the universe just be filled with a pile of particles floating around? also, what happens to matter in a black hole? does it simply disappear, squashed into nothingness?

what about the jets of particles that shoot out from black holes when their anti particle is pulled over the event horizon? will the universe just be filled with a pile of particles floating around? also, what happens to matter in a black hole? does it simply disappear, squashed into nothingness?

I've never heard of the jets being caused by anti-particles. Our universe is pretty much exclusively matter so there are no anti-particles around! The jets are a result of the conservation of angular momentum. These should ensure that not all matter is swallowed up but there would be very little left and it would not be dense enough to form stars or galaxies.

The matter in a black hole does not cease to exist. If it did then a black hole would not have the huge gravity that it does. Over time matter actually leaks out of a black hole via a form of quantum tunneling called Hawking Radiation. So, in effect blackholes evaporate over billions of years.

Now, as to what happens in the longer term it all comes down to the rate of expansion of the universe. If there is enough matter in the universe all the black holes will get pulled into each other and reverse the expansion of the universe and basically cause a 'big crunch', if on the other hand there is not enough matter in the universe to slow and reverse the expansion then the universe will expand so rapidly that the stuff that evaporates from the blackholes will be spread out so thinly that the whole universe will essentially become empty. The latter is what current measurements of the expansion seem to be implying.

Nobody really knows whats in the centre of a black hole.
Our knowledge of Physics breaks down at a "singularity".
It'll probably take a "new physics" to explain it.

Anyway new physics comes along every few centuries and all the rules are re-written.

In a thousand years time it will all be tame stuff which we "ancients" were too thick to understand !

to explain the jets of particles, from my understanding, particles are just "appearing" in the universe all the time, but these particles and their antiparticles obliterate eachother, and so its as if they dont exist, but at a black hole, some of the anti particles get sucked over the event horison , leaving the particles as they wont get obliterated by their opposite. these particles are then spewed out of the black hole by this angular momentum. thats how i understand it. and this is what is hawking radiation.

The matter in a black hole does not cease to exist.

so your saying the matter is converted into huge amounts of energy? or is it converted into some exotic type of matter?

Ive been looking into this a bit, but not being a physist its difficult to comprehend!

if there is a black hole in the centre of all galaxies, does that mean that eventually all matter in the universe will be sucked in to these and there will be nothing left?

Generally speaking, astronomers do not envisage a supermassive black hole at the centre of a galaxy being able to eat the entire galaxy. Remember that a black hole can only suck in material within the range of its gravitational pull determined by its mass. Purely as an example, as this event can't actually happen, if the Sun suddenly became a black hole, the planets would stay where they are as the gravitational pull of the Sun as a black hole would be the same as it was when a star. Only if objects stray close enough to the black hole would its gravitational pull eventually draw them in. That's how black holes grow. At the centre of a galaxy, a black hole could grow by pulling in passing stars which just happened to get too close in their galactic orbits. The supermassive black hole at the centre of the Milky Way is estimated at 3.2 to 4 million solar masses in a space 10 times smaller than the Earth's orbit around the Sun.

I've never heard of the jets being caused by anti-particles. Our universe is pretty much exclusively matter so there are no anti-particles around!

Oh yes there are. Gamma ray satellites looking for radiation at the energy of electron positron annihilation have found plenty in the galactic center.

www.spacetoday.org/DeepSpace/Galaxies/MilkyWay/Antimatter.html

to explain the jets of particles, from my understanding, particles are just "appearing" in the universe all the time, but these particles and their antiparticles obliterate eachother, and so its as if they dont exist, but at a black hole, some of the anti particles get sucked over the event horison , leaving the particles as they wont get obliterated by their opposite. these particles are then spewed out of the black hole by this angular momentum. thats how i understand it. and this is what is hawking radiation.

Thats more or less my understanding also. The uncertainty principle tells us that particles and their antiparticles can be created but can only exist for a very short amount of time.

Hi just adding my imput to this

When we are talking about what happens at the very very end you have to understand that time will be no impedement Things that you dismiss as not being able to happen actually will happen given enough time for chance and things which are improboble occuring.

Therefore eventually the central black hole will gobble up all the matter in the galaxy. The stars which orbit the black hole out in the galaxy
are constamtly interacting with other stars also in orbit aroud the galaxy and thus exchanging orbital energy. Some stars will loose energy (and some gain energy) and thus fall into an orbit which is slightly closer to the black hole then before. In this way they will eventually fall in given enough time. In the same way for instance that we see that some of the globular clusters are now undergoing gravitational collapse.

The solar system would appear to be a pretty stable piece of work with all the orbits of the planets staying in the same place. But if you run it forward 1000s of billions of years into the future u see that they do indeed change orbits. As there is a net loss of orbital energy from the solar system due to gravity waves. It will mean that in the far far far distant future all the planets will eventually fall into the sun (or the freezing cold remnant of it called a black dwarf).

There is the other theory which states that the proton itself is unstable and will itself disassociate into elementary particles. So given enough time we will all just disappear to nothingness.

to explain the jets of particles, from my understanding, particles are just "appearing" in the universe all the time, but these particles and their antiparticles obliterate eachother, and so its as if they dont exist, but at a black hole, some of the anti particles get sucked over the event horison , leaving the particles as they wont get obliterated by their opposite. these particles are then spewed out of the black hole by this angular momentum. thats how i understand it. and this is what is hawking radiation.

I'm no expert but you seem to be mixing up two separate concepts, Jets and Hawking Radiation. They are entirely separate phenomena. Jets are matter being ejected by the accretion process and are powered by excess angular momentum. The matter has not crossed the event-horizon before it is ejected in the jets. Hawking radiation is a really slow quantum process that can be explained by a number of analogies including the one you quoted above. It happens over billions of years and does not result in a powerful jet but an unbeluevably slow trickle of matter presumably in all directions rather than as a concentrated jet.

Yup, Hawking radiation is the way in which Black holes "evaporate" over time, as the particle/antiparticle pairs form and one is captured on the event horuzon while the other escapes, so the mass of the object is reduced, just a little, this has no short term effect on super massive blackholes but big consequences for smaller ones.
The supermassive galactic cores will probably outlast most other objects in the universe, aside from odd socks and cockroaches.
Also the geometry of space time plus rotation amongst other things may well govern if this garden spot of a universe is destined for a crunch or a continual expansion. It almost comes down to a religious faith, what outcome makes you most comfortable. Me, no end, baby universes spawned from this one, each one taking from the characteristics of the one that spawned it, a whole multiverse kinda thing, statistically we have to be simply one of a range of possible universes that are possible, each no more remarkable than the last, this only different because we are here at the mo to gaze out and ask questions, doubtless not the only ones to do that either.

so when all the black holes evapourate, the matter that has evapourated from them ( in the form of energy or radation i gues) is still around. it is my understanding that energy/matter cannot be destroyed, only have its form chaged ( from energy to matter or vice versa). therefore there always has to be the same amount of matter/energy in the universe. by that time we will have purchased another turtle and live n top of that one i guess!