How many planets are there?

In elementary school, I - like millions of other kids - learned that there were nine planets in our solar system. It was a fact - couldn't argue with it - and it had always been that way (at least as far as we were concerned - Pluto was actually discovered in 1930).

Turns out that facts aren't always facts. The international body of astronomers, after considerable debate, are facing a decision: because Pluto is so different from the other planets, we either have to stop calling it a planet or we need to add some more planets based on the revised definition. That leaves us with either 8 or 12 planets, including a celestial body charmingly named 2003 UB313. (Article here for more information.)

I mention this as a reminder to anyone interested in education reform. Just because everybody knows something - just because everyone looks at something the same way and calls it a fact - doesn't mean it's right, and it doesn't mean that you can't look at things differently over time.

There are facts, and there are "facts". 2+2=4 is a fact. Pluto's existence is a fact. But whether Pluto is a planet is not a matter of fact: it depends on how we define a planet, and that's not only subjective, it's also somewhat arbitrary.

Same things with schools. As Christian Long points out today at Think:Lab, in the whole great history of mankind, we've only been doing public schooling for the last 200 years or so. There are no hard and fast scientific laws as to how schooling has to be. Schools do not have to be as they have always been. We can change the definition. We can change the desired outcomes. We can change the processes.

It may look like an impossible task, given the size of this $700 billion juggernaut we call an education system. But anyone who "knew" that there were nine planets should take comfort in the fact that that things don't have to be what they've always been.