Friday, June 22, 2012

Kepler-36's 'Odd Couple' Defy Planet Formation Theories

There's a general axiom of science that the observer isn't specially priveleged. In other words, when it comes to astronomy, what we see looking out is similar to what everyone else would see. The trouble with that idea is that, because of statistical laws, it has to break down at some level - if you look for, say, 20 different things, each with a very high, say, 95% chance of occuring, there will probably be at least one that looks seriously atypical from your viewpoint (assuming those things can be treated independently, of course). Scientists tend to argue that on some scale the universe looks uniform to all observers, but that's not actually as useful a starting assumption as it sounds, because no one is sure just what that scale's boundrys are, the minimum sample needed is, or just what things are or aren't 'unifomitarian'.
? ? ? ? For example, some 19th and early 20th century astronomers observing our own solar system, thought that Earth's having such a large moon was very unusual, and if there were extra-solar, earth-like worlds, they would usually have much smaller moons, if any. But until we can image objects the size of our moon across interstellar distances, for all we know, Venus and Mars are unusual in not having larger moons (or any moon at all in the case of Venus). The common idea, that Earth-Moon like 'double planets' are rare, is based on damned near no data.
? ? ? ? ? For another, the Sun and the Moon have almost exactly the same apparent diameter as seen from Earth - surely that's just a statistically unusual coincidence, but technically, we don't really know but that it might be anomalously common, and in complete contrast to the random ratios we might expect, for the same situation to occur elsewhere.
? ? ? ? ? Maybe it will turn out that gas giants in a system typically range from a largest one in the closer orbit, outward to a smallest gas giant in the largest of a series of orbits, (and our solar system mostly fits a standard rule) or maybe our solar system has it bass ackwards, or maybe gas giant size and orbit distribution is completely random.
? ? ? ? ? ? One minor point: There are no stars 10 times older than our sun. At 4.75 billion years old, the sun is about 1/3 the age of the entire universe, so even the earliest stars formed are only about 2 1/2 times as old. So i'll predict that, if there's more 'odd configurations' in older star systems, it will have to manefest itself over a smaller range of ages.

usher fidel castro rick santorum ozzie guillen castro comments phish gluten free diet barry zito

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.