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Q & A: spinning black holes

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Most recent answer: 04/29/2010
Q:
hi. i am in 12 th.i once observed something.if the star that the black hole is made up of is spinning in the normal way as it was doing before the formation of black hole, it would actually help in increasing the effect of gravity hence causing greater depression in the space time fabric.this way the strength of the black hole should increases along with its engulfing mass.and that means at some time it should become so large that the existence of the galaxy it is located in is threatened.and it can be easily proved by proving the existence of a black hole near our galaxy...so a problem for us. now my question is it correct.and if yes , can we talk about the motion of the black hole w.r.t its galaxy.then how does our galaxy still exists if the black hole is moving.. this wat i feel having seen tops revolve and they can cause the elastic under them to get more curved..(so can bend the path of a moving object...)... thank u for ur time........
- apurva (age 17)
A:
Black holes can spin, but I'm not sure why you think that makes a major difference in how they attract other matter. There are some subtle 'frame-dragging' effects, but not the sort of thing you're wondering about.

There is a large black hole in the center of our galaxy, about 3 million solar masses, if I remember right. In the long run, such black holes will indeed gobble up the other things. In the even longer run, they will themselves evaporate via Hawking radiation, unless some other sort of physics sets in on that very long term.

Mike W.

(published on 04/29/2010)

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