> Good point, Dave. Scientists like to talk about
>how they use scientific method to find the truth
>and truth is all that matters, but many of them
>have pet theories and they look for evidence that
>supports those theories. If they ignore other
>evidence that might disprove their theory, they
>aren't being very scientific.

As wintermute pointed out, this really wasn't science they were doing. It's just coming up with a definition of what a planet is. In that respect, it's totally OK to just say "Here are the things I think are worthy of being called planets" and figuring out what those things have in common so you can come up with your definition.

The only reason this is even an issue right now is because astronomers are finding more and more KBOs that are as big or bigger than Pluto. The question then becomes, are they planets too? If so, how many more planets are we going to add? If not, then why is Pluto a planet? Just because we've always said it is?

Honestly, any of those solutions is just as "correct" as any other. Personally, I think the most elegant solution was the one they settled on. But in order to figure out if these things are planets or not, you first have to figure out what the hell a "planet" is. It would have been ok to just say "We've got nine planets, we're not going to add any more no matter what" but that in my mind just seems silly and arbitrary. Sure, the definition they came up with might be arbitrary too, but somehow it seems *less* arbitrary to me than just saying "Nine planets. End of story."

-- Dave