the Pluto controversy continues
In light of discussions previously held on the list, here is another article on Pluto - Nothing new. http://www.cnn.com/2005/TECH/space/02/13/pluto.anniv.ap/index.html --------------------------------- Do you Yahoo!? Yahoo! Search presents - Jib Jab's 'Second Term'
Are we talking about regular-size angels or minis? -- Joe
So, how many angels can fit on the head of a pin?
Kim _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com
On Feb 15, 2005, at 11:20 AM, Kim Hyatt wrote:
So, how many angels can fit on the head of a pin?
Kim
Angels dancing on the head of a pin... This phrase often triggers a snort of ridicule, but I learned (while a grad student in math) that what was being pondered was the idea of infinity–a useful concept. There are a lot of things that sound silly, while having depth behind them. Topology has a "hairy egg theorem" stating that an egg covered in hair cannot be combed with the hair lying flat everywhere (some might call it the cowlick theorem). It is really a theorem about sections of the tangent bundle of a topological sphere. But "hairy egg" is such an evocative name. I would guess "angels dancing" was a similarly evocative name. The Jordan curve theorem states that a simple closed curve lying in a plane has an outside and an inside. It is surprisingly hard to prove (actually it is easy once the necessary algebraic topology machinery is constructed), though it seems to be so obvious. People used to make fun of medieval medicine's use of leeches. Today, leaches are once again used for treatment. Let us not be too quick to be contemptuous. Jim ---- Jim Cobb james@cobb.name
Sorry, Jim - I wasn't being contemptuous, but amused. Planet, planetoid, Kuiper Belt Object... the arguments are purely semantic and don't change the fact that Pluto is an unusual and interesting place. I just don't think that the arguments are productive. "I say tomato, you say tomahto..." I heard once that the IAU was planning to define a "planet" as any object whose size is such that its own gravity will make it spherical. Anyone else heard that? If true, then our own Solar System obviously has more than nine "planets." Kim ----- Original Message ----- From: Jim Cobb<mailto:james@cobb.name> To: Utah Astronomy<mailto:utah-astronomy@mailman.xmission.com> Sent: Tuesday, February 15, 2005 11:37 AM Subject: Re: [Utah-astronomy] the Pluto controversy continues On Feb 15, 2005, at 11:20 AM, Kim Hyatt wrote:
So, how many angels can fit on the head of a pin?
Kim
Angels dancing on the head of a pin... This phrase often triggers a snort of ridicule, but I learned (while a grad student in math) that what was being pondered was the idea of infinity–a useful concept. There are a lot of things that sound silly, while having depth behind them. Topology has a "hairy egg theorem" stating that an egg covered in hair cannot be combed with the hair lying flat everywhere (some might call it the cowlick theorem). It is really a theorem about sections of the tangent bundle of a topological sphere. But "hairy egg" is such an evocative name. I would guess "angels dancing" was a similarly evocative name. The Jordan curve theorem states that a simple closed curve lying in a plane has an outside and an inside. It is surprisingly hard to prove (actually it is easy once the necessary algebraic topology machinery is constructed), though it seems to be so obvious. People used to make fun of medieval medicine's use of leeches. Today, leaches are once again used for treatment. Let us not be too quick to be contemptuous. Jim ---- Jim Cobb james@cobb.name<mailto:james@cobb.name>
participants (4)
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Jim Cobb -
Jim Gibson -
Joe Bauman -
Kim Hyatt