Pain over Pluto

Via Andrew Sullivan, Astronomer Adam Frank wonders why striking Pluto from the list of planets has upset so many people:

After pondering the problem for some time, I believe our collective grief over Pluto's demise as a planet is not because of its link to a dopey Disney dog but because of something deeper: a hunger for order and simplicity.

In the last 20 years something remarkable has happened in our understanding of solar systems and, in some deep recess of our collective imaginations, we just don't like it.

We have come of age. We have grown up. Instead of the tidy vision we were taught as children, with nine planets moving along their color coded orbits, we now know that solar systems can be very messy places.

From studies of other solar systems (discovered only since 1995), we know that giant Jupiter-sized planets can live right up against their stars in orbits so close it would make Mercury blush. We know that rather than the stately circles our planets move along, some of these systems have giant planets winging back and forth on wildly cigar-shaped orbits (ellipses) that can play hell with smaller Earth-sized worlds tossing them into the frozen depths of space just (perhaps) as life was getting going. And in our own corner of the galaxy, this solar system that once seemed so orderly and compact (even with that untidy asteroid belt) is now populated by all manner of malformed worldlets.

I concur. People like answers. People like for things to be definitely one thing or another. People like for things to stand still and be named. People don't want to be told that "planet" is just a word that does not correspond exactly to any natural category; they wants planets to be a real thing, their number fixed by God or ancient physics. I think this is part of why evolution is upsetting to some people, and why so few people really understand what scientists (or historians) do.