Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site decwrl.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!nsc!decwrl!daemon From: daemon@decwrl.UUCP (The devil himself) Newsgroups: net.puzzle Subject: Re: Does the hole expand when heated? Message-ID: <1114@decwrl.UUCP> Date: Mon, 28-Oct-85 13:29:05 EST Article-I.D.: decwrl.1114 Posted: Mon Oct 28 13:29:05 1985 Date-Received: Wed, 30-Oct-85 04:55:16 EST Organization: Digital Equipment Corporation Lines: 30 Concerning the problem: Does the hole expand when the metal around the hole is heated? Try it for yourself! Here's how... [This experiment is given in the 7th grade General Science book published by D.C. Heath, 1961. I used it many times in my former junior high science teaching days to prove that metal expands when heated.] You need 2 pieces of apparatus: 1) loop of 1/4" thick metal, attached to a wooden handle so it can be held in a flame without burning yourself. 2) ball that just fits through the metal loop, attached to a wooden handle so you can hold it easily. Procedure: Holding the loop by its handle, place the metal end in a flame for a minute or so (We used a gas burner, but even a fireplace will do). Then try to fit the ball apparatus through the loop. You will find that the heated metal has expanded in all directions (including inward into the space of the hole), making the hole smaller so that the ball no longer fits through the loop. Once the loop cools off, the ball will once again be able to fit through. A M A Z I N G !