Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site inteloc.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!ihnp4!zehntel!dual!qantel!intelca!omsvax!inteloa!inteloc!bill From: bill@inteloc.UUCP Newsgroups: net.physics Subject: Helium baloon in car Message-ID: <157@inteloc.UUCP> Date: Thu, 13-Sep-84 13:01:02 EDT Article-I.D.: inteloc.157 Posted: Thu Sep 13 13:01:02 1984 Date-Received: Tue, 25-Sep-84 02:25:32 EDT Organization: Intel Corp, Hillsboro, OR Lines: 19 > If you have a helium balloon in the car with you (and your fuzzy > dice), you will see something really strange: the balloon will lean in the > opposite direction the dice do. The explanation I've always heard for this > is that the balloon's motion is dominated by buoyant forces; when the air > in the car feels a centrifugal force and goes one way, the balloon goes > the other way. This is not strange at all: everything inside the car is being acted upon by the same resultant force. Since this force is toward the outside of the curve, the dice lean that way, while the baloon floats in the opposite direction. All the turning has done is to change the local definitions of "up" and "down" physically, while all of our visual clues support the "classical" (straight-line) definitions. -- T.F.Prune (Bill Wickart) {allegra | ihnp4 | tektronix} !ogcvax!inteloa -- "Operator, trace this call and tell me where I am"