Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: Notesfiles $Revision: 1.6.2.17 $; site uiucdcsb.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!inuxc!pur-ee!uiucdcsb!robison From: robison@uiucdcsb.UUCP Newsgroups: net.physics Subject: Re: Re: Floating a battleship in a gallo Message-ID: <10800013@uiucdcsb.UUCP> Date: Tue, 11-Dec-84 11:45:00 EST Article-I.D.: uiucdcsb.10800013 Posted: Tue Dec 11 11:45:00 1984 Date-Received: Thu, 13-Dec-84 00:47:42 EST References: <1297@hao.UUCP> Lines: 39 Nf-ID: #R:hao:-129700:uiucdcsb:10800013:000:1533 Nf-From: uiucdcsb!robison Dec 11 10:45:00 1984 But a ship can float in a small amount of water by Archimedes principle. It's not the water around the ship that counts, but the displaced water - which need not exist. In the example, the 100,000 ton reservoirs may be removed with no effect: \~~~| 100,000 tons |~~~/ \~~\ /~~/ \~~\ /~~/ \~~\ SHIP /~~/ \~~\ /~~/ \~~\ /~~/ \~~\ /~~/ \~~\ /~~/ \~~\--/~~/ \~~~~~~/ \----/ (The pressure on the container walls is about 1 atmosphere for every 10 meters of depth, the same as if the ship was not there!) This trick was used by Michelson and Morly to float their interferometer table (ACK! back to FTL!) on a small amount of mercury. If I remember correctly, the geometry was like this: +----------------------+ | Table | | +----------+ | |m| |m| |m| |m| |m+-----+m| |m+-----+m| |mmmmmmmmm| |mmmmmmmmm| |---------| |---------| The table is set in a trough of mercury (m's). The weight of the mercury in the trough is far less than the weight of the table. It is the displaced mercury (which isn't there) that holds the table up! Arch - uiucdcs