Pluto Retires at 76

I’ve spent the last 10 days ensconced in a news-free enclave by the lake. For all I know, Lebanon is nothing but one large smoldering crater by now. Or maybe we’ve pulled out of Iraq. But one news tidbit did leak into the otherwise info-sterile cottage. Pluto is no longer a planet.

This triggered a cottage wide debate which divided the house into two factions. On the one side, Pluto is just a big rock in a funky orbit and isn’t really distinguishable from all the other similar size rocks in similar orbits which seem to be circling the sun in greater numbers than we knew. On the other, Pluto has always been a planet, so why mess with it now? There was clearly no healing this rift, so we did the only logical thing – broke out the snacks until everyone was in a sugar coma and couldn’t have cared less.

But in retrospect, I think there are some important lessons to be learned. Up until now, there has never been a formal definition of “planet”. It was sort of like the pornography of astronomy. You knew it when you saw it. But recent discoveries of several more Pluto-like bodies in our solar system, as well as the discovery of a number of extra-solar planets, some several times larger than Jupiter, created the need for a more formal definition. Do we make the other rocks planets too, or downgrade Pluto?

The third option of grandfathering Pluto as a planet and ignoring the others is not really an option that the science community could cope with. It rather defies the whole point of science to allow exceptions to definitions. Besides, the argument of “it’s always been that way” is really a generation centric comment. It would be like arguing that there have always been 50 stars on the American flag. Historically, that’s just not true. But it has been true in our lifetime.

Further, I think it’s a great lesson for those not in the science field that science is all about revision and continued understanding. Even if that new understanding means you have to back up and admit that you were wrong before. This happens all the time in science, just not too often in areas that the general public actually perceives. When I was in school, protons and electrons were indivisible particles. No one knew about quarks, much less strings. Dinosaurs used to be cold blooded lizards. The sun used to orbit the earth, which itself, used to be rather flat. New information brings revisions in understanding of how the universe works. This is the very essence of science.

It’s disingenuous for people to bark that scientists can’t be trusted because they keep changing their minds. That connotes a notion of whimsy to the revisions. That’s not how it works. Science is exacting and meticulous; it’s collaborative; it’s iterative; and it’s not above saying it was wrong.

You can either accept that as a good thing, or risk sailing off the edge of your precariously flat earth.