Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/12/84; site nbs-amrf.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!lll-crg!gymble!umcp-cs!nbs-amrf!hopp From: hopp@nbs-amrf.UUCP (Ted Hopp) Newsgroups: net.puzzle,net.math Subject: Re: Re: Polar Bear Problem Sequel Message-ID: <42@nbs-amrf.UUCP> Date: Mon, 28-Oct-85 20:49:30 EST Article-I.D.: nbs-amrf.42 Posted: Mon Oct 28 20:49:30 1985 Date-Received: Fri, 1-Nov-85 00:46:10 EST References: <361@proper.UUCP> <367@faron.UUCP> <10755@ucbvax.ARPA> Distribution: net Organization: National Bureau of Standards Lines: 25 Xref: linus net.puzzle:1027 net.math:2084 > By the way: heat causes metal to expand. If you have a piece of metal > with a spherical hole in it, does the hole expand, contract, or remain > the same when the metal is heated? What about a square hole? I don't > know the answer! > > ...ranjit bhatnagar If you heat the metal enough, it will glow. The hole will then be a black hole, and therefore contract forever. Oh, I'm sorry. I thought we were in net.physics.newman ;-) Actually, the hole (spherical, square, circular, or whatever) will expand. Imagine heating the metal that filled the hole when the metal was cool while you are heating the metal with the hole. The "filler" will fit back into the hole when both are hot. Since the filler chunk expanded (being metal), the hole must have expanded. As to why the filler should fit back in, imagine heating the metal plus filler without separating the filler - if it isn't going to fit in when heated separately, why does it exactly fill where the hole would have been? -- Ted Hopp {seismo,umcp-cs}!nbs-amrf!hopp