There can only be one

[foodchain]

Say you have two black holes of equal mass, equal distance apart from each other, in fact the black holes are mirror images of one another really, what would occur if they were close enough to act on each other? Allow for no other variables to exist in this environment, such as another planet for instance, its just the two black holes.

 

*Its a thought experiment I guess, I don’t know where I should have placed it. So if an admin wants to move such, go ahead I am fine with that.

[Sisyphus]

Define "close enough to act on each other."

 

In most circumstances, you can just treat them as ordinary massive bodies, in which case they'll most likely just orbit one another. If there is no lateral motion, like any other massive bodies, they'll crash into one another. I don't what would happen then, but I imagine you'd get a crazy release of energy. Or maybe not, since all that energy would have to just be reabsorbed into itself as mass, and you'd just have one, bigger black hole.

[foodchain]

Define "close enough to act on each other."

 

In most circumstances, you can just treat them as ordinary massive bodies, in which case they'll most likely just orbit one another. If there is no lateral motion, like any other massive bodies, they'll crash into one another. I don't what would happen then, but I imagine you'd get a crazy release of energy. Or maybe not, since all that energy would have to just be reabsorbed into itself as mass, and you'd just have one, bigger black hole.

 

I guess close enough would be the point in which the gravity of either black hole directly acts on its counterpart. I am not to sure as to the current definition of gravity in physics, or really the range gravity has I guess really.

 

I was thinking about the effect such would have on spacetime. I mean if left alone in an orbital pattern, what would be the limit to the effect on spacetime? I also wonder how QM would play into this such as if on the collision scenario.

[Sisyphus]

Again, "directly acts?" If you just mean pull on one another, then the gravity of a black hole has no different effects from the gravity of a planet or a star. If the Earth, say, were to collapse into a black hole somehow (never mind how), that black hole would continue orbiting the sun in exactly the same way, the moon would orbit the black hole, all the satellites and the international space station and everything else would all stay in exactly the same orbits as they are now. The only differences would be in the region that is now the interior of the Earth, where the force of gravity, instead of linearly decreasing to zero as it does now, would exponentially increase as you move towards the center, up until the event horizon and whatever lies beyond. But, before the event horizon, it's still just "a lot" of gravity, not any kind of "special" gravity.

[foodchain]

Again, "directly acts?" If you just mean pull on one another, then the gravity of a black hole has no different effects from the gravity of a planet or a star. If the Earth, say, were to collapse into a black hole somehow (never mind how), that black hole would continue orbiting the sun in exactly the same way, the moon would orbit the black hole, all the satellites and the international space station and everything else would all stay in exactly the same orbits as they are now. The only differences would be in the region that is now the interior of the Earth, where the force of gravity, instead of linearly decreasing to zero as it does now, would exponentially increase as you move towards the center, up until the event horizon and whatever lies beyond. But, before the event horizon, it's still just "a lot" of gravity, not any kind of "special" gravity.

 

 

So the intense effects of a black hole, such as light not being able to escape it is a product of more or less the black hole internally and not so much its gravitational prowess? So if a duplicate of Jupiter in regards to its physical properties such as mass for example was replaced with a twin save it was a black hole no real change would occur to our solar system?

[pioneer]

If they were mirror images they would have opposite spin. The problem this may create is which is going to be the final spin? You get a figure eight where both are having a tub-of-war for dominance. One possible solution for this deadlock is the entire figure eight will begin rotating in a perpendicular plane. This will give a common spin allowing them to combine with the composite perpendicular to the two daughters BH.

[iNow]

Say you have two black holes of equal mass, equal distance apart from each other, in fact the black holes are mirror images of one another really, what would occur if they were close enough to act on each other?

When visualizing it in your mind, try to consider it the same as you would two stars orbiting each other. They would get closer and closer, and they would have a measurable impact on spacetime and the light around them. Eventually, one would swallow the other (since pertubations would prevent them from being EXACTLY the same). Here is a visual in the context of gravitational waves offered by NASA's LISA group:

 

 

 

 

 

Also, here is some research on actual BHs orbiting:

 

http://www.nrao.edu/pr/2006/binarybh/

These two giant black holes are only about 24 light-years apart, and that's more than 100 times closer than any pair found before," said Cristina Rodriguez, of the University of New Mexico (UNM) and Simon Bolivar University in Venezuela. Black holes are concentrations of mass with gravity so strong that not even light can escape them.

 

The black hole pair is in the center of a galaxy called 0402+379, some 750 million light-years from Earth. Astronomers presume that each of the supermassive black holes was once at the core of a separate galaxy, then the two galaxies collided, leaving the black holes orbiting each other. The black holes orbit each other about once every 150,000 years, the scientists say.

 

"If two black holes like these were to collide, that event would create the type of strong gravitational waves that physicists hope to detect with instruments now under construction," said Gregory Taylor, of UNM. The physicists will need to wait, though: the astronomers calculate that the black holes in 0402+379 won't collide for about a billion billion years.

 

See link for more.

[Innit]

I'm a total newbie at this topic, as I'm still doing my GCSEs (10th grade), but hasn't it been said that previously, 2 galaxies have collided, and together have joined to form 1 galaxy. From my knowledge, there are supermassive black holes (which are millions to billions times the mass of the sun) in the centre of galaxies, as there is one in the Milky Way. Somehow, I suppose, these black holes have joined to make one (NoteL This may be completely wrong, and I may have been misguided, because I also thought, as the above post states, that those two black holes were the closest apart!). One may have "consumed" the other, I am not sure. But if they are exactly the same size, maybe they would do orbit one another, like planets do. But I suppose that it would not be a normal circular motion. One would not be orbiting the other, they would be orbiting each other simultaneously. I have no idea what I'm talking about right now, but I think I'll stop there, before I confuse myself and others anymore!

[iNow]

hasn't it been said that previously, 2 galaxies have collided, and together have joined to form 1 galaxy.

There was actually a press release just under a month ago from the NASA Spitzer Space Telescope team indicating that they observed 4 galaxies colliding... actually observed it.

 

 

http://www.spitzer.caltech.edu/Media/releases/ssc2007-13/release.shtml

Four galaxies are slamming into each other and kicking up billions of stars in one of the largest cosmic smash-ups ever observed.

 

The clashing galaxies, spotted by NASA's Spitzer Space Telescope, will eventually merge into a single, behemoth galaxy up to 10 times as massive as our own Milky Way. This rare sighting provides an unprecedented look at how the most massive galaxies in the universe form.

 

"Most of the galaxy mergers we already knew about are like compact cars crashing together," said Kenneth Rines of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. "What we have here is like four sand trucks smashing together, flinging sand everywhere." Rines is lead author of a new paper accepted for publication in Astrophysical Journal Letters.

 

Collisions, or mergers, between galaxies are common in the universe. Gravity causes some galaxies that are close together to tangle and ultimately unite over a period of millions of years. Though stars in merging galaxies are tossed around like sand, they have a lot of space between them and survive the ride. Our Milky Way galaxy will team up with the Andromeda galaxy in five billion years.

 

Mergers between one big galaxy and several small ones, called minor mergers, are well documented. For example, one of the most elaborate known minor mergers is taking place in the Spiderweb galaxy -- a massive galaxy that is catching dozens of small ones in its "web" of gravity. Astronomers have also witnessed "major" mergers among pairs of galaxies that are similar in size. But no major mergers between multiple hefty galaxies -- the big rigs of the galaxy world -- have been seen until now.

 

More at the link.

[Innit]

^ Ooh! That was an interesting article! Thanks for sharing it!