What would happen if a black hole passed the event horizon of a black hole?

Consider a binary pair of black holes, one larger than the other, should the smaller one be drawn across the event horizon at some point and if so, what do you think would happen?


Interesting insight wolvensense...But say two galaxies are moving towards each other (like the Milky Way and Andromeda)... how would the black holes at the center interact if the event horizons were close enough to each other?

Update 2:

Wait a minute wolvensense... your analogy is incorrect. There is substance at the center of a black hole, it small and super dense. Comparing that to an empty space defined by its walls is not the same. I'm interested in the resulting reaction of two (or more) black hole in close proximity. And your bugs bunny reference could be considered insultory. Cartoons are funny, but my question is serious and thoughtful if you're interested in astronomy at all. Asteroids collide, comets fly into things (shoemaker levy), and even galaxies merge... I wasn't looking for a second-grader's defintion and explanation of the nature of a hole

10 Answers

  • 1 decade ago
    Favorite Answer

    i think both will attract each other and will eventually become a single black hole in middle of both centre but closer to bigger one as it have more power ...

  • Anonymous
    1 decade ago

    The bigger black hole sucks up the other one and becomes a more dense massive black hole. If two of near equal density come near each other, at a fast enough speed, a speed faster than there abilities to suck the other up into oblivion before they collide, they both collide and cause a big bang. Or should I say, a small scale big bang. Which happens all the time and is how small new gallaxies are made. It's like recycled, massive energy.

    And I'm sure you know this part, but just in case....Rememeber, black holes aren't really actual empty holes in space, they are super dense stars we cannot see because light can't escape it.

  • 1 decade ago

    First I think you would see less matter being pulled into the event horizon of the smaller one. At a guess I would say that at some point a convergence of the two could result in a single black hole but I don't believe it's observable. It would be interesting to see if there were a difference in the particles emitted as they converged. Neat question! I'd hate to be doing the math on this one.

  • 1 decade ago

    I think there's a fundamental flaw with the query here. See, a black hole is not actually a "thing." They exist. They are real. Yet, the hole itself is actually the absence of things, of matter, a gravity well so strong that it can bend and pull in light. We give the parts of it names, like the part that is the event horizon (the distance from center at which the gravity well starts or stops pulling light in) yet the hole is a negative construct, a non-entity.

    Think of a Bugs Bunny rabbit hole. While we see it because of the earth or the Brooklyn pavement that surrounds it, the hole itself is nothing. In a cartoon we can treat it as something. We can pull it from the ground and stick it on the wall. We can even put one hole into another hole by making "something" of one, objectifying it, portraying it as matter that can be grabbed and then slipping it into the remaining negative space of the second. Yet, that's fiction.

    Think of a hole in the ground now in real life. Again, we can see it because of the earth or the orange cones that surround it, but what we have named as the hole itself doesn't have a form. It is empty. It is the space between sides of the hole. Sure, on earth, there's air in there, but even the matter that is air is not what we are talking about when we talk about a hole. The hole is simply the void of a schism.

    Well, black holes were named as such when postulating that their gravitational forces could pull in light. They were presumed to be these black holes in space that went through to another universe. However, space is a big hole. You can't have a hole in a hole. While space contains countless amounts of matter, again, what we refer to as space is the nothingness in between the matter, the void.

    So, to take the question literally, one black hole cannot really criss-cross another if we are treating them in conversation as actual holes.

    Now...if we are treating them as instead, gravity wells, you come up with a null answer as well. See, when we think of space, we think of weightlessness. In actuality, while we are weightless compared to the pull of earth's gravity, there is no such thing as true weightlessness. If there was only one tiny object in the universe that had a gravitational pull, that pull would go on to infinity. It gets ever weaker the further form the object one goes. Yet, even if you were floating a lifetime away from that object, you'd be very slowly pulled in that direction. So, there is no place in space that is not affected by gravity. If you were floating out between entire galaxies, you would slowly be pulled in the direction of the galaxy with the stronger gravitational force. The force of other galaxies acting on you might slow you, or change the angle at which you are pulled there, but you'd be pulled there nonetheless. All the gravities acting on you at once form this collective pull on you and determine your vector.

    So, in this "light," two gravity wells whose event horizons cross are no longer really two events, they are a collective gravity indistinguishable as a pair. Light is either going to get ultimately pulled toward one former center or toward another, all into vectors changing as the horizon(s) cross, but that can be easily looked at as a single new horizon.

    Make no mistake. I am not definitively saying that the two would BECOME one. I am saying that if the gravity well of the first is somehow strong enough to actually pull closer the massive central collapsed star of another, in some ways, the perceived two always were just one. They can only be defined as TWO if they never interacted with each other at all. Hence the problem with the question.

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  • 1 decade ago

    Best question yet.

    If you subscribe to the quantum physics notion that matter is just space between far-flung particles(that probably consist of even more space) there is limitless opportunity for compression. Therefore, if the larger black hole has sufficiant density to pull the smaller across its event horizon, it would be absorbed without incident.

    In fact, this probably happens on a routine basis. I once had a tank full of extremely agressive File fish. In 3 days, only one fish remained, and he looked to be about the same size as always. I suspect similar goings on in space.

  • Anonymous
    1 decade ago

    Happens all the time. Most spiral galaxies like the MW have superhuge black holes called Star Jones, I mean, in the center of the galaxy that are the result of many black holes combining.

  • 4 years ago

    it is undecided that no longer something can get away the form Horizon and we don't comprehend what occurs in a black hollow. count must be thorn aside in quarks, quarks in ...... and black holes may be linked in subspace, and if debris may be swifter then gentle then it is attainable that some debris would get away a black hollow and its journey Horizon. no longer something is advantageous.

  • 1 decade ago

    I recall reading about how NASA had done some simulations on this very thing with their SGI supercomputer. The question has relevance for those researching the existence of gravitational waves.

  • Anonymous
    1 decade ago


  • Anonymous
    1 decade ago

    They would both disappear...

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