[Pszinygv]

Thanks Neeyik, that's interesting stuff.
-----------------------------------
@Insanechild
Sorry i can't answer your question and in fact have one of my own again. [rofl]

How does a black hole manage to eject material when it becomes a Quasar? Is the mass of the black hole reduced so the gravitational forces are not so great, or is it just a case of it feeding until it has to vomit some mass out again? If it's mass doesn't somehow get reduced then how and why can the matter ejected from it's centre escape?

EDIT: Just had a thought, unless it's because the matter is ejected along the edge of the event horizon where the pull is less?

[engideNedmupe]

Thanks Neeyik, that's interesting stuff.
-----------------------------------
@Insanechild
Sorry i can't answer your question and in fact have one of my own again. [rofl]

How does a black hole manage to eject material when it becomes a Quasar? Is the mass of the black hole reduced so the gravitational forces are not so great, or is it just a case of it feeding until it has to vomit some mass out again? If it's mass doesn't somehow get reduced then how and why can the matter ejected from it's centre escape?

EDIT: Just had a thought, unless it's because the matter is ejected along the edge of the event horizon where the pull is less?

Heh, I think I can answer that one. Yes, your afterthought was correct. Any mass/radiation ejected is from outside of the event horizon, where the particles are being ripped apart.

Nothing comes out of from beyond the event horizon, absolutely nothing. Except maybe Chuck Norris's foot, to roundhouse-kick you in the head.

[CurtisTH]

Its theorized that this repulsive force might even eventually reach the point when the remaining Stars and Planets and in fact anything material are torn apart as atoms themselves became repulsed from one another.....

It would need to become immensely strong to do that though - so much so that your query ("Would there be any black holes remaining in that far distant time?") would essentially become moot, as the forces that bind electron and nucleons together utterly overwhelm the estimated expansion "force" and gravity now; thus, if it did somehow change to become significantly larger, all known nuclear and electromagnetic processes would cease....

What happens to the event horizons (specifically their radii) when those of 2 blackholes cross one another?

Given that the event horizons are simply arbitary (well, somewhat arbitrary) boundaries in heavily curved spacetime, each black hole will influence the other's spacetime curvature, so the event horizons will become modified accordingly. A bit of net scouring found this simple animation to demonstrate the point:



(Source)

How does a black hole manage to eject material when it becomes a Quasar?

As InsaneChild pointed out, the ejection occurs some distance away from the event horizon in the accretion disc around the hole - just as with all black holes. It's worth noting that black holes don't become quasars: the latter are thought to be galaxies with a highly active nucleus. So it would be a case of: matter condenses to form stars, which condense to form a galaxy; black holes form within that galaxy which eventually (the exact mechanism is still open to conjecture) results in a supermassive black hole at the centre of the galaxy. Some additional mechanism results in either a huge accretion disc forming around the SBH or a large quantity of mass is "absorbed" by the SBH very rapidly: either way, it releases immensely powerful matter/radiation jets, making the galaxy visible today, despite the large redshift present.

[wpFWNoIt]

Neeyik your great[thumbup]

[JAMES PIETERSE]

Things can orbit larger black holes forever and a day. In the middle of the Milky Way it is said there is a Supermasive Blackhole, we and everything else in the Milky Way quite happly orbit it. It is thought that all Galaxys have a Supermasive Blackhole in the middle, like an "engine" if you will. Meanwhile, M31 (Thats Andromeda Galaxy) has 2 Supermassive's in its middle, albeit one is much smaller than the other. And then theres M51 (Whirlpool Galaxy) whose supermassive blackhole has created a "cross" pattern with all the dust that orbits the blackhole.

http://en.wikipedia.org/wiki/File:M5...black_hole.jpg

PS. Spot the guy whos gone back to Uni to study Astronmy lol

[Flieteewell]

Neeyik your great[thumbup]

I agree.

Neeyik, you ever though of holding an online live seminar? It seems every time I read your posts I have many questions I want to ask, but don't want to bombard you.

[engideNedmupe]

Given that the event horizons are simply arbitary (well, somewhat arbitrary) boundaries in heavily curved spacetime, each black hole will influence the other's spacetime curvature, so the event horizons will become modified accordingly. A bit of net scouring found this simple animation to demonstrate the point:



(Source)

Well, the reason I ask stems back to the "using artificial gravity to escape from within the event horizon" question.

If, theoretically, there is a device which can create (and terminate) a gravity source that is on the scale of a black hole, is it not possible that such a device can be used to alter the boundaries of the event horizon of a black hole such that an object that has already crossed it can be "pulled back" outside again?

[MpNelQTU]

I love these threads, they always go like so:

- People who are clueless on the topic telling people what would happen.
- Neeyik coming into the thread (and also generally proving many people wrong).
- Everyone turning to Neeyik and asking him a quadrillion questions.

Don't take any offense, I've most likely been guilty of it in the past too! I just find it funny....

[Flieteewell]

I love these threads, they always go like so:

- People who are clueless on the topic telling people what would happen.
- Neeyik coming into the thread (and also generally proving many people wrong).
- Everyone turning to Neeyik and asking him a quadrillion questions.

Don't take any offense, I've most likely been guilty of it in the past too! I just find it funny....

I totally disagree...

Neeyik... perhaps you can explain why this is?

[rofl]

[Alupleintilla]

I love these threads, they always go like so:

- People who are clueless on the topic telling people what would happen.
- Neeyik coming into the thread (and also generally proving many people wrong).
- Everyone turning to Neeyik and asking him a quadrillion questions.

Don't take any offense, I've most likely been guilty of it in the past too! I just find it funny....

Whew, thank God.

It has been almost a week since I saw the last Tidy_Sammy holier-than-thou post. I thought there was a problem.

I am glad you are okay.

[isopsmypovA]

I totally disagree...

Neeyik... perhaps you can explain why this is?

[rofl]

Haha!

For reference, I also found these threads very interesting.

[wpFWNoIt]

It would need to become immensely strong to do that though - so much so that your query ("Would there be any black holes remaining in that far distant time?") would essentially become moot, as the forces that bind electron and nucleons together utterly overwhelm the estimated expansion "force" and gravity now; thus, if it did somehow change to become significantly larger, all known nuclear and electromagnetic processes would cease....

I read what you said to mean that with no interactions, there could be no processes. Yet as I was wandering the web, trying to answer my own question, I came across a few papers suggesting that a big rip Universe might become incredibly strange towards the end, with a surprising possible role for black holes at a point well before processes cease.

(I do note that the authors acknowledge that more rigorous study is needed.)

http://arxiv.org/pdf/0806.2521v2

As usual (since I was a kid) I wander around all big-eyed, asking questions!