Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site mordor.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!ut-sally!mordor!@S1-A.ARPA,@MIT-MC.ARPA:MILLER@YALE.ARPA From: @S1-A.ARPA,@MIT-MC.ARPA:MILLER@YALE.ARPA Newsgroups: net.space Subject: Angular Momentum, Inertia, and IMAX. References Included. Message-ID: <2631@mordor.UUCP> Date: Fri, 12-Jul-85 12:22:49 EDT Article-I.D.: mordor.2631 Posted: Fri Jul 12 12:22:49 1985 Date-Received: Tue, 16-Jul-85 01:44:15 EDT Sender: daemon@mordor.UUCP Organization: S-1 Project, LLNL Lines: 24 From: David MillerThe reason the IMAX camera is difficult to move is due to the "gyroscopic effect" put on the camera by the rotating film reels. This was pointed out in the original article. All of the suggestions having to do with counter rotating reels will not diminish this effect at all. Angular momentum has direction and can be cancelled by an equal amount in the opposite direction. "Gyroscopic effect" is due to INERTIA and is a magnitude independent of direction. Marion's "Calssical Dynamics" Chapter 12 has a good explanation on the subject. But for a more intuitive situation think of two gyroscopes rotating in opposite direction. Now attach their outer frames. The outsides will stop rotating, but the gyroscopes will not topple over (as a cancellation of gyroscopic effect would indicate). Instead, the entire system is more stable than its parts. Inertial guidance systems have relied on this for years. They are crammed full of gyroscopes in all orientations and rotating in different directions. --David Miller -------