Re: Pluto is a planet again! (in Illinois)

On Sun, 8 Mar 2009 20:35:08 -0700 (PDT), Quadibloc <jsavard@xxxxxxxxx>
wrote:

But Mr. Kelleher also said that there were nine planets, but validated
Pluto's claim by an argument which gives the definition that would
admit all the asteroids, and so on, as planets too. So he is
contradicting himself.

I hate to defend anything Gerald says, but I see no contradiction. There
_are_ nine planets (by one accepted definition). And all asteroids _are_
planets as well (by another accepted definition).

The thing that makes "planet" such a useful word is precisely its lack
of rigorous definition. We are better off using other words, or
modifiers, when we need precision. Like Davoud says, there was no
problem that required solving by the IAU.
_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
.