There’s a science fiction tale or two to be dug out of this little science item, I’m thinking:

If the latest simulation of what happens when black holes merge is correct, there could be hundreds of rogue black holes, each weighing several thousand times the mass of the sun, roaming around the Milky Way galaxy.

The simulation in question is focused on “intermediate mass” black holes, and there isn’t really even any strong evidence that such things, weighing a few thousand solar masses, exist. (Via PhysOrg.)

Still, if they exist, and two of them of different sizes and rotating at different speeds combine, the simulation indicates resulting merged black hole gets a kick in the pants that can hurl it away in an arbitrary direction at a velocity that averages 200 kilometres per second but in some instances can be as high as 4,000 kilometres per second–enough in either case to allow the black hole to escape the globular cluster where these intermediate black holes (if they exist) are predicted to form.

The researchers are reassuring:

“These rogue black holes are extremely unlikely to do any damage to us in the lifetime of the universe,” Holley-Bockelmann stresses. “Their danger zone, the Schwarzschild radius, is really tiny, only a few hundred kilometers. There are far more dangerous things in our neighborhood!”

Of course, anything with a mass of a few thousands suns wandering close to the solar system is going to play havoc with planetary orbits…but fortunately, space is very, very big.

It’s probably nothing to worry about.

(Image: Ute Kraus, Max-Planck-Institut für Gravitationsphysik, Golm, and Theoretische Astrophysik, Universität Tübingen, www.spacetimetravel.org)

[tags]astronomy, space, black holes[/tags]