Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site decwrl.UUCP Path: utzoo!watmath!clyde!burl!ulysses!unc!mcnc!decvax!decwrl!dec-rhea!dec-sprite!osman From: osman@sprite.DEC (Eric, 617 273-7484, Burlington, Ma. 01803, USA) Newsgroups: net.math Subject: Which has more points, the unit square, or the unit line segment ? Message-ID: <1767@decwrl.UUCP> Date: Mon, 22-Apr-85 17:07:31 EST Article-I.D.: decwrl.1767 Posted: Mon Apr 22 17:07:31 1985 Date-Received: Wed, 24-Apr-85 02:57:14 EST Sender: daemon@decwrl.UUCP Organization: DEC Engineering Network Lines: 16 I recall being told that the comparison of the size of two infinities is resolved by finding a mapping function from one to the other. If the mapping function can be demonstrated to map EVERY element from the first set onto EVERY element of the second, then the infinities are the same. I suspect that the number of points on a line segment and a unit square are the same. Can anyone come up with a mapping function that maps the P in segment [0,1] to some (X,Y) in square [(0,0),(1,1)] such that the mapping provides complete coverage ? If perhaps you have a mapping function that works on (0,1] or some other variation of open/closed interval combinations, that would be fine too. /Eric Osman, Digital, Burlington, Ma, 01803, USA