tino@hou2f.UUCP (A.TINO) (10/29/85)
>> Since the piece of metal expands uniformly when it is heated, >>the hole must expand. If you use a square hole, consider the >>portion of the metal that runs along an edge of the square hole. >>If this rod-shaped portion of the metal piece was heated by itself, >>it would expand in length; so it must also expand in length when it >>is part of the hole. Thus, the length of the side of the hole must get >>bigger and the hole expands. >> > >Quite an UNconvincing argument. The rod would get fatter too, >suggesting it's wideness intrudes into the square, so perhaps >the square hole gets *smaller*. _________________________________________ True, the rod will get fatter but the net effect of expansion is to uniformly increase every linear dimension. Including the dimensions of the hole. Think of it this way: Imagine the piece of metal as a 3x3 square. It can be thought of as nine 1x1 squares. Cut out the middle 1x1 piece to form a hole. Thus the metal now consists of eight 1x1 pieces arranged to form a square. When the metal is heated each small piece will expand to form a larger square. The eight expanded pieces still fit together perfectly to form the original square pattern. Thus the hole has to end up as large as the expanded 1x1 pieces. Everything expands! Al Tino
matt@oddjob.UUCP (Matt Crawford) (10/31/85)
More fuel for the fire: You hole-expansion-or-contraction debaters seem to be overlooking the fact that when I put a pan of cookies in the oven the cookie sheet spontaneously warps itself when it heats up a bit. _____________________________________________________ Matt University crawford@anl-mcs.arpa Crawford of Chicago ihnp4!oddjob!matt