Sun, 27 Aug 2006
Pluto Demoted
I shouldn't let Pluto's demotion from planetary status go unnoticed. According to the new definition, a planet must:
- Orbit a star, but not be a star
- Have sufficient mass to give it a spherical shape
- Clear its orbit of other bodies
The last element in the definition is new and is the reason why Pluto was demoted, because it intersects the orbit of Neptune. But it's not clear to me why Neptune doesn't also fail the new definition. I must be missing something. In any case the definition of a planet is arbitrary. Let me plug George Lakoff's book, Women, Fire and Dangerous Things, which argues that people categorize things according to their resemblance to an object in the category that is considered typical (an exemplar) and not according to some list of properties that all members of category possess. Of course, astronomers are not the only ones affected by the decision. Consider the poor astrologers. Western astrologers have been charting the position of many non-planetary bodies (e.g., the lunar nodes) for a long time, so they shouldn't be too upset. I don't know if Indian and Chinese astrologers have any opinion. This Tibetan astrologer argues that science is finally following Buddhism's lead.
"This decision is of no importance for us. We do not mind demoting Pluto down from the planethood. Indeed, Pluto has never been considered a planet in the Tibetan astrology", Sanjey-Lama said to Interfax on Friday.
He says the Buddhist astrological system has never given Pluto the importance it has attached to other planets; it has always considered it "rather a gasiform entity or a comet".
The representative of the Russian Buddhists stressed that it often happened in the history of the world science that scientists "make discoveries after we did them".
