Thank God, We're Not Food For Black Holes

We should all go down on our knees, and thank the Almighty, “Oh, thank you, dear Lord, we’re not in the path of those planet-chomping invisible rogue black holes.”

Yesterday, Jan. 9, US astronomers announced that hundreds of invisible rogue black holes may be roaming around our Milky Way galaxy – our own neighborhood in the Universe — waiting to engulf stars and planets that cross their path.

The astronomers believe these “intermediate mass” black holes are invisible except in rare circumstances and have been spawned by mergers of black holes within globular clusters — swarms of stars held together by their mutual gravity.

Lest they caused global panic, the astronomers hastened to add that these black holes are unlikely to pose a threat to Earth, although they may engulf nebulae, stars and planets that stray into their paths.

“These rogue black holes are extremely unlikely to do any damage to us in the lifetime of the universe,” said Kelly Holley-Bockelmann, an assistant professor of physics and astronomy at Vanderbilt University in Nashville, Tennessee.

“Their danger zone, the Schwarzschild radius, (or gravitational radius) is really tiny, only a few hundred kilometers. There are far more dangerous things in our neighbourhood.”

She didn’t elaborate what other “dangerous things” await planet Earth. Whew! They must be too scary to reveal.

Anyway, Holley-Bockelmann and her colleagues at the University of Michigan and Penn State University simulated what would happen if intermediate mass black holes combined with stellar-sized black holes, which are plentiful in globular clusters.

Using sophisticated computer modeling, they calculated that these mergers would generate hundreds of mid-size black holes, and that the force of their combinations would catapult them out of the globular cluster at speeds of up to 4,000 kilometers per second.

That would leave these black holes, each weighing several times the mass of the sun, to careen around interstellar space, unattached to any stellar system, at high speeds. Hence the term rogue.

Bockelmann presented her findings Wednesday at the 211th American Astronomical Society meeting in Austin, Texas.

Indeed, we can consider ourselves the luckiest creations of the Universe. We live in a self-sustaining world (at least for now) in a part of the universe quite far from where all sorts of riotous actions are taking place. Despite all the conflicts, all the sadness, all the miseries all around us – we still have I-Pods, cellphones, laptops, music, movies, caring families, and true friends to share our lives with. Aren’t we so lucky?