Space Nutrition
We’d never really thought about it before, but it makes sense that black holes have to eat, too, and given their nature it’s not surprising that they should display ferocious appetites. A new theory now suggests that the black hole that many astronomers presume to be at the center of our own Milky Way galaxy--presume, because black holes can only be inferred, not seen--keeps itself in business, so to speak, by sucking in a stream of gaseous molecules that had its origin trillions of miles away. This at any rate is the speculation of Prof. Paul Ho of Harvard University, who led a team of scientists that believes it has found the energy source that keeps billions of stars in our galaxy in orbit.
Reaching out for a fuel source is necessary because a black hole at the center of the Milky Way, if one exists, would long since have devoured most of the mass around it, perhaps along with any passing star that was unfortunate enough to wander too close. A black hole is thought to be a star that has collapsed in on itself, perhaps shrinking to a diameter of only a few miles, but becoming so incredibly dense that its gravitational pull prevents even light from escaping. Having done in its neighbors and grown larger in the process, the black hole would then, as we understand the theory, begin feeding on whatever other matter it could pull in. Ho and his colleagues think that in the case of the Milky Way black hole that’s a stream of gas at least 15 light years long, emanating from a huge cloud of molecular gas 25 light years away. As astronomers measure these things, 25 light years isn’t all that distant. But as the crow flies it’s about 150 trillion miles, which perhaps says something about the universe’s remarkable synergy.
Not all astronomers accept this latest theory, but without choosing sides in any budding cosmological controversy we’re bound to say that it’s fine with us, since we’re always happy to see loose ends tied up. But the real charm of this story, we think, is in its reminder that in the overall scheme of things Earthly problems can suddenly be made to seem remarkably insignificant. Yes, this is where we live, and we would be remiss if we didn’t worry about war and peace and planetary pollution and why big budget deficits are not good. But out there, whether we pay attention or not, the cosmos rolls along, unimaginable in its immensity, following its own rules of order, creating and destroying, a thing that as it more and more comes to be understood is more and more revealed as a thing of boundless wonder.
