In orbit

Last night Zdenek and I watched a fascinating Nova episode called "Monster of the Milky Way." As we learned, there is likely a large (but not too large) black hole at the center of our galaxy. Luckily, our black hole is mostly in a "famine" state right now, and so it's not gobbling up everything around it and emitting harmful radiation in the process; it'll be another 10 million years at least before we all need to be wearing x-ray shields. Astronomers inferred the existence of our galactic black hole by tracking the velocities of stars orbiting the galactic center. As the stars approach the black hole, the immense gravitational pull speeds them up and whips them around on their elliptical orbits.

One of the questions that Zdenek and I pondered as we watched this show (and kept pausing it to argue -- it was like the blind leading the blind) was why orbits are so often elliptical rather than circular (although, to be fair, a circle is merely one form of an ellipse in with both axes are equal). My quick scan of the internet last night pulled up no satisfactory answers. Fortunately, I happen to work with dozens of PhD-level physicists, one of whom, in fact, previously studied and simulated the structure of the universe. Even better, he sits only four offices down the hall from me. As I suspected, he was indeed able to provide me with a clear explanation of how elliptical orbits are formed and why they persist, and he reassured me that the sun will likely burn out before we'll get eaten by a black hole. Apparently we have two or three billion years to go.

All of this is good news, because I'm supposed to be embarking on an elliptical orbit of my own on Saturday, and it would be unfortunate if some black hole or dying sun impeded my travels. We are heading home, and I can't wait. Leading up to this trip, I've been putting in as much running and cycling as I can find time for. It's been eleven days of consecutive runs or rides thus far, and my legs are starting to feel the burn. I keep pushing just a little bit more, though, because there awaits a ten day stretch during which cycling will be impossible and running will be limited.

Zdenek and I have commented several times in the last few weeks that only in the current economic climate would he have so much time for so much non-work-related activity. We keep watching and waiting, wondering when something big might happen to change our orbit, but in the meantime, we're taking full advantage. One might say that we're circling a black hole of our own right now, but so long as it doesn't gobble us up altogether, it only serves to make us go faster.