USS Clueless              Voyages of a restless mind

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Stardate 20011008.2004 (On Screen): There is so much yet that we do not know. Good science asks two new questions for every question it answers. I imagine a conversation with a creationist: he says, "But your science is incomplete." I answer, "Yes, isn't that wonderful?"

Each time we create a new instrument which is more sensitive than those which came before it, more is revealed to us and it never fails to puzzle. I have been watching the public announcements from the Very Large Telescope project in La Silla, one of the finest pieces of engineering on the planet. It will be the most sensitive telescope in existence when it is completed, but in the mean time they are already discovering amazing things with it. They have located a double star whose plane of rotation in in line with us, so that they eclipse each other. This permits extremely precise calculations of the diameters of the two stars and of their orbital period, and that combined with spectroscopic analysis has permitted a very precise characterization of them. They are both very young, less than ten million years old, and their orbital period is only three days; they are calculated to be only 8 million km apart, one seventh of the distance from Mercury to the Sun. Which is puzzling: how could two stars form so close together? Or if not that, how could they come to be in such a close orbit so soon after formation? How did they shed their kinetic energy to come into such close orbit?

One possibility is that they are in retrograde orbits, so that they both spin clockwise but orbit around each other counter-clockwise. If so, then tidal bulges on each would try to fight rotational energy; and they would approach each other more and more closely as they rotated less and less rapidly; the process would end either in collision or with the two bodies being tide-locked to each other, with their rotational periods and orbital periods identical. There's no way yet to tell whether that's happened. The energy involved would manifest as heat in the two stars (from turbulence), added to the heat of collapse.

Up to about 25 years ago, enormous work was done trying to explain planetery formation based on our knowledge of our own system, and a plausible mechanism was described. But most of the external stellar systems with planets which have now been discovered don't make sense within that model. They're in strange orbits: gas giants closer than Mercury, or with orbits almost like comets. There is so much yet to learn. Isn't it wonderful? (discuss)