Friday, October 10, 2014

Pluto is or isn't a planet

This happened recently. Short version, some people are still upset about the 2009 redefinition of Pluto to 'not a planet'. Quoting from the article: "The decision did not sit well with the public. Some amateur stargazers and some astronomers thought it rather arbitrary." So they held some kind of vote and the audience voted to 'reinstate' Pluto as a planet.

You remember when the whole 'Pluto isn't a planet' thing happened right? It was all over the media, and people were up in arms on social media. You'd think it was BIG SCIENCE NEWS based on all that. I got asked recently, as I did several times back then, what was my position on it since I'm an 'astronomy person'. My position is I don't care. This isn't BIG SCIENCE NEWS, it's semantics. Nothing new was discovered, no new theory was proposed. Whether you call Pluto a planet or not changes nothing about what it is. It's trivial.

Here's the thing, I don't think this is a one-off misunderstanding about Pluto. I think this is a symptom of a deeper problem that a lot of people don't understand a fundamental aspect of science. Here's an illustration of the 'Pluto problem':

The 'problem' here has nothing to do with Pluto, it's taking the black-and-white taxonomic categories too literally. The universe (at least on the macroscopic scale) is a continuum, but we like to classify things into boxes. This or that, is or is not. But the real world just isn't like that. Where do you draw the line separating the 'planet' box from the 'not a planet' box? You can draw it anywhere, and no matter where you put it the things on one side of the line aren't going to be very different from the things on the other side of the line. You try to put the line in the most useful place possible but it's still arbitrary by it's very nature. This is a 'problem' of applying binary logic to a continuum.

I'm not sure if this system of categorizing things into boxes is useful in itself or it's only useful because our brains want to work that way, but either way it's useful. The concept of a species is extremely useful in biology even if, when you look close, you realize the concept doesn't apply very well to the reality. Taking the concept for reality is probably a big factor in popular misunderstandings and misrepresentations of evolution - it's pretty easy to take the concept and say something silly like 'one species can't give birth to another', and that makes sense if you think 'species' represents a real division in nature.

I'm not saying to forget the boxes, the boxes are still a useful way of thinking. But at the end of the day you have to remember we invented the boxes. We decide what goes in what box, and putting something in one box rather than another doesn't change anything about the way things are. It's a mental tool to help you understand how things relate to one another; the boxes aren't a real part of nature.

"Some amateur stargazers and some astronomers thought it rather arbitrary." Well duh.

As an aside, I should mention something about how thousands of science enthusiasts got up in arms to defend the way they were taught rather than being willing to change their mental model to best fit the world. This is the same attitude they'll decry in their anti-science bogeymen.