What makes a black hole spin.?

Answer 1

uglue42 is correct. The spin of a black hole is inherited by the spin of the star that preceeded its formation. Since most stars rotate, it is believed that most black holes spin as well.

Answer 2

I may have read too much scifi, BUT

A star spins because it really is orbiting the center of mass of its "planetary" system. the star's planets, comets, asteroids, and dust must perforce orbit this same center of mass in the same direction. As the star captures first dust, then asteroids, then comets it gains in mass. The orbits of the remaining planets and debris become more and more eccentric, until they, to collide with the star. Meanwhile the star's diameter is shrinking from the increased gravitation. Once the star captures enough mass for it's "escape velocity" to equal the speed of light, even light cannot escape, and all the star's mass/energy is believed to be contained within the Scchwarzchild radius, r = 2*M*G/c^2.

At no time in all this process does anything happen to diminish the angular momentum of the system, so black holes spin.

Answer 3

I believe it is gravity that makes it spin. Black holes are celestial objects with gravity so intense that nothing, not even light, can escape from them once past their boundary, called the event horizon. This makes a black hole invisible, but black holes reveal their presence by their strong pull on matter that is close to -- but not beyond -- their event horizons.

Answer 4

It spins because the star was spinning when it collapsed.
Also the singularity DOESN'T SPIN - the matter and energy on the event horizon spins.

Answer 5

Hi. Rotational inertia.

Answer 6

Her husband?