I cannot resist: Reducing Pluto's classification as planet to non-planet might just be the tip of the iceberg. DH
David K. Hogberg, PhD Professor of Psychology, Emeritus Albion College, Albion MI 49224 [EMAIL PROTECTED] home phone: 517/629-4834 >>> [EMAIL PROTECTED] 08/26/06 10:20 AM >>> Stephen says: "Nope, don't agree. When Pluto was first designated a planet, it was thought to be much larger than it is now. It's been systematically whittled down over the years to a really tiny hunk of rock. Also, it was once thought to be unique, but an increasing number of bodies like it have now been discovered, such as Xena (wonderful name, which unfortunately is=20 only temporary), and Xena turns out to be larger than Pluto." 1) If the known size of Pluto fluctuated over the years and that is actually what caused it to be removed from classification as a planet, it is a pretty big coincidence that they realized how small it actually was on the same day that the definition of a planet was revised to remove Pluto from consideration. 2) There was another proposal under consideration to include many more bodies (such as Xena) as planets. Finding out that Pluto is not unique does not necessarily logically lead to the conclusion that we must change the definition of a planet to make sure it doesn't include these other exemplars. Were astronomers going to be inconvenienced by having more planets? Or, in the conspiratorial mode popular on TIPS of late, might it be that proponents of No Child Left Behind decided too many children would be left behind if they needed to learn the names of more planets rather than less? It is all a matter of language (and evidently the body was only concerned about the English language -- what will they do in Ontario?) 3) The vote was not concerning whether Pluto still met the requirements to be a planet but what the requirements to be a planet are. Pluto was not at issue; the definition of a planet was. Once again, the current definition of a "planet" is: "a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighborhood around its orbit." Pluto fulfills a and b but not c so it is a dwarf planet which is probably an unfortunate misnomer (I am sure they would prefer to be referred to as little planets or, in APA style, planets diagnosed with dwarfism) given that size is only indirectly part of this definition. The main part of the definition relating to size is b and Pluto meets that requirement. I assume larger bodies are also more likely to have cleared the neighborhood around their orbits. I guess there must be a precise definition of what it means to clear your neighborhood. The Earth still runs into occasional trash in our neighborhood, some of which might one day be big enough to do us serious harm. Rick Dr. Rick Froman, Chair Division of Humanities and Social Sciences Professor of Psychology John Brown University 2000 W. University Siloam Springs, AR 72761 [EMAIL PROTECTED] (479) 524-7295 http://www.jbu.edu/academics/hss/psych/faculty.asp "Pete, it's a fool that looks for logic in the chambers of the human heart." - Ulysses Everett McGill -----Original Message----- From: Stephen Black [mailto:[EMAIL PROTECTED] Sent: Friday, August 25, 2006 3:00 PM To: Teaching in the Psychological Sciences (TIPS) Subject: [tips] Pluto's chromosomes On 25 Aug 2006 at 10:55, Rick Froman wrote: > I believe that the Pluto story is actually a better example of paragraph 2 > than of paragraph 1 in Marc's post. I don't think it is a good example at all > of how scientists expect change in our conclusions as data accumulates. No > new data accumulated to make this change.=20 Nope, don't agree. When Pluto was first designated a planet, it was thought to be much=20 larger than it is now. It's been systematically whittled down over the years to a really tiny=20 hunk of rock. Also, it was once thought to be unique, but an increasing number of bodies=20 like it have now been discovered, such as Xena (wonderful name, which unfortunately is=20 only temporary), and Xena turns out to be larger than Pluto. =20 That's all new data, which had an important influence on the decision to boot Pluto (or else admit too many others into the club). So, all your base is belong to us. =20 Stephen ----------------------------------------------------------------- Stephen L. Black, Ph.D. =20 Department of Psychology =20 Bishop's University e-mail: [EMAIL PROTECTED] 2600 College St. Sherbrooke QC J1M 0C8 Canada Dept web page at http://www.ubishops.ca/ccc/div/soc/psy TIPS discussion list for psychology teachers at http://faculty.frostburg.edu/psyc/southerly/tips/index.htm ----------------------------------------------------------------------- --- To make changes to your subscription go to: http://acsun.frostburg.edu/cgi-bin/lyris.pl?enter=3Dtips&text_mode=3D0&l a= ng=3D english --- To make changes to your subscription go to: http://acsun.frostburg.edu/cgi-bin/lyris.pl?enter=tips&text_mode=0&lang=english --- To make changes to your subscription go to: http://acsun.frostburg.edu/cgi-bin/lyris.pl?enter=tips&text_mode=0&lang=english
