Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/26/83; site ihuxr.UUCP Path: utzoo!linus!decvax!harpo!gummo!whuxlb!pyuxll!eisx!npoiv!npois!hogpc!houxm!ihnp4!ihuxr!lew From: lew@ihuxr.UUCP Newsgroups: net.math Subject: followup to "Everything you know is wrong!" Message-ID: <563@ihuxr.UUCP> Date: Wed, 17-Aug-83 17:34:02 EDT Article-I.D.: ihuxr.563 Posted: Wed Aug 17 17:34:02 1983 Date-Received: Thu, 18-Aug-83 02:20:45 EDT Organization: BTL Naperville, Il. Lines: 19 Perhaps not everyone will believe me when I say that my "proof" was given tongue-in-cheek. Anyway, many people easily saw the flaw in it. Takashi Iwasawa pointed out that every polyhedron circumscribed on a sphere (faces tangent to the sphere) has a surface/volume ratio of 3/r. You can see this by dividing the enclosed volume into pyramids with the faces as bases, and radii of the sphere as heights. the 3/r comes from the volume of a pyramid being B*h/3. Steve Sommars wondered about the generalization of the minimal surface property of a sphere to N dimensions. Actually, I don't know how you'd prove it in 3 dimensions, for that matter. There must be a clever way. The 3/r S/V ratio of the circumscribed polyhedra seems to provide a way, but this only shows that the sphere has the minimum surface area among a restricted class of shapes (of a given volume!) Lew Mammel, Jr. ihuxr!lew