Milky Way's "other" black hole

[bobvanx]

I love stuff like this!<br /><br />This middle-weight black hole, newly discovered, zipping around the galactic center at 280 km/sec (!!!) is still an enigma: did it come from the collapse of a globular cluster? Is it formed similar to the way smaller eddies are formed around a whirlpool, ie simple gaseous collapse? What happens to the galactic black holes from the galaxies the Milky Way cannibalizes?

 

[Maddad]

"<font color="yellow">What happens to the galactic black holes from the galaxies the Milky Way cannibalizes?</font><br /><br />They probably wind up zipping around the galactic center at 280 km/sec.

 

[Grok]

Can two black holes ever break each other's event horizons, or would their opposite forces balance and create a state of equilibrium? In other words can you turn off a black hole by pushing it against another black hole?

 

[qzzq]

To create balance or a static equilibrium you need two opposite forces cancelling each other out. Gravity is the only one of the four fundamental forces that knows no opposit force; there is no + to cancel out the -. Gravity is always + ( or - , depends whether you're an optimist or a pessimist I guess...<img src="/images/icons/crazy.gif" />) Two black holes always attract each other. The black holes would simply collide and form one bigger black hole. The event horizon is just a virtual border. It might be that when their event horizons meet, collision can not be avoided anymore. It sure causes a ripple in the fabric in space time when something like that happens. <br /><br />www.curtin.edu.au/curtin/dept/phys-sci/gravity/index2.htm<br /><br />Click 'advanced' and then 'gravitational waves', scroll down a bit and there you'll find a graphic representation of what a collision of two black holes would 'look' like. <div class="Discussion_UserSignature"> <p> </p><p>***</p> </div>

 

[nexium]

Canabalize may be a poor choice of words. It is generally thought that galaxies pass though each other with only rare colisions other than the gas clouds. Most of the stars, planets, asteroids and moons are perturbed only slightly. Comets are likely scattered.<br /> After the encounter the speed difference is reduced slightly and the direction changed perhaps a few seconds of arc. Neil

 

[nexium]

The event horizons are a tiny target so they rarely over lap during a near miss. When they do, the less massive black hole may be swallowed or end up orbiting the more massive black hole at very high speed. If the mass is about equal, and the speed differece is large, my guess is a third body is formed from the over lapped mass, which may escape both event horizons, however, odds are about even that one of the black holes will gobble up the third body in the next million years or so, which means it did not realy escape the event horizon. Neil

 

[Grok]

qzzq,<br /><br />That was an interesting animation. Here's a question. I'm assuming that at some point a black hole would have a "limit". When it reached this limit it would be too dense to accept more mass, so anything new that comes along would have to be repelled. That appears to be the theoretical negative that would cancel out a positive. In that case, if you had two mature black holes that ran into each other, and neither could accept the mass from another black hole, would they merely bounce off each other and go their own ways?

 

[qzzq]

<i>I'm assuming that at some point a black hole would have a "limit".</i><br /><br />None that we know of. You could squeeze the entire mass of the Universe into one black hole and there'd be no problems whatsoever. As far as we know. There's really only intelligent speculation on what happens inside the event horizon of a black hole. The votes are still out on what gravity even is. <div class="Discussion_UserSignature"> <p> </p><p>***</p> </div>

 

[Grok]

qzzq,<br /><br />That leads to the next question. If a black hole has no limit, then it appears that it would have the effect of grabbing up larger and larger objects and the universe would soon disappear into the black hole. This hasn't happened yet, which is why I speculated that there must be a limit.

 

[Maddad]

grok<br />The limit may well be time. The universe is extremely young at only 10¹⁸ seconds old. The last of the supermassive black holes will evaporate when the universe is 10¹⁰⁸ seconds old or thereabouts. It will then be 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 times older than it is today.

 

[Grok]

Evaporate? Into what?

 

[qzzq]

The Universe is a really, really big place. Black holes are lucky to bump into snacks now and then. Merging black holes are very rare. And a black hole's gravity is less than the star it was born from, so its effect on it surroundings is likewise smaller. And a limit? The black holes at the center of galaxies are billions times as massive as our Sun. If there is a limit, it sure is not having an effect on the most massive objects we know. <br /><br />And we're past the great age of black hole formation, the early Universe, when short lived massive stars were far, far more abundant than these days. Less stars going nova means fewer black holes. And we're expanding at nearly the speed of light, not contracting into a Universal black hole. <div class="Discussion_UserSignature"> <p> </p><p>***</p> </div>

 

[Grok]

qzzq,<br /><br />Aren't your points in line with my reasoning. If black holes didn't have a limit, then the universe would be contracting. We would all be getting sucked back into whatever is the biggest black hole out there.

 

[qzzq]

Yes, perhaps, but the most massive objects we know don't seem to be bothered with some kind of limit. We really don't know why the Universe is expanding. Gravity curves the fabric of space time. Anti-gravity would do what? Anti-curve space time? Un-curve it? I'm heaving trouble grasping anti-gravity I guess. Perhaps if gravity is communicated by a wave/particle, a ripple through space-time, and you'd make it complety run out of phase, you'd have an anti-graviton communicating anti-gravity. Hmmm... <div class="Discussion_UserSignature"> <p> </p><p>***</p> </div>

 

[Grok]

steve,<br /><br />What's causing this continued expansion? Is it just leftover momentum from the big bang? It seems counterintuitive to think we're madly rushing away from everything, and everything from us without some force causing it.

 

[bobvanx]

I like the notion that the current discovery of increased expension is related to the Early Inflationary Period, and that there is a (-) component to gravity.<br /><br />I read an article about the expansion, and the repurcussions of this observation. The most interesting idea to me, was that the increased "shear" across vast distances was literally pulling fresh subatomic particles from the void... in effect, re-inventing the idea of the "Steady State" Universe, but with an open curve to space-time.

 

[robnissen]

"If a black hole has no limit, then it appears that it would have the effect of grabbing up larger and larger objects and the universe would soon disappear into the black hole. This hasn't happened yet, which is why I speculated that there must be a limit." <br /><br />That is not true. From a graviatational standpoint, a black hole is no different than any other body. For example, if a very massive star has planets in a stable orbit around it, if that star collapses into a black hole, the planets will remain in their stable orbits. The gravitational pull of the black hole is no stronger than the gravitational pull of the massive star because their mass is the same. The only difference is that the mass is concentrated in a very small point, so that close to that point, the gravitational pull is very large. The only place the graviatational pull is stronger for the black hole than for the steller mass, is inside the old radius of the massive star. The reason why the graviational pull is stonger there, is because there is no countervailing pull. For example, as you head inside a star (or the earth), there is a gravitational force pulling you towards the center, but that force is partially counteracted by the mass of the surface pulling you towards the surface. A black hole does not have that countervailing force, because all the mass is concentrated in a singularity of the black hole. <br /><br />This was just a long winded way of saying, that as long as an object doesn't cross the radius of the collapsed massive star, the black hole has no different gravitational effects than did the massive star before it collapsed. And therefore, the universe will not end its days sucked into a giant black hole.

 

[a_lost_packet_]

Ditto on what RobNissen said.<br /><br />A black-hole only has the "gravity effect" of it's mass. It has no "extra" gravity just because it is a "black hole." It's mass concentrated at a very small point which has some very extreme, localized effects we're still trying to figure out. Objects can still orbit such phenomenon without being "sucked in."<br /><br /> <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>