tino@hou2f.UUCP (A.TINO) (10/29/85)
>Concerning the problem: Organization: AT&T Bell Labs, Holmdel NJ Lines: 38 > >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 ! ________________________________________ That would be AMAZING if it were true. I just don't believe it!!!!! I would believe the following demo: make the ball just a little too big to fit through the metal ring when the ring is at room temperature. Now if you heat the ring, it expands --THE HOLE GETS BIGGER!!! When the ring is hot the ball passes through it easily. Al Tino