Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site eagle.UUCP Path: utzoo!watmath!clyde!burl!ulysses!eagle!mjs From: mjs@eagle.UUCP (M.J.Shannon) Newsgroups: net.aviation,net.astro Subject: Re: Something else to watch out for! Message-ID: <1271@eagle.UUCP> Date: Wed, 26-Jun-85 08:29:24 EDT Article-I.D.: eagle.1271 Posted: Wed Jun 26 08:29:24 1985 Date-Received: Thu, 27-Jun-85 06:42:57 EDT References: <11270@brl-tgr.ARPA> <1199@phoenix.UUCP> <1679@amdahl.UUCP> <122@shell.UUCP>, <377@iham1.UUCP> <186@maxvax.UUCP> Organization: AT&T Bell Laboratories, Summit, NJ Lines: 18 Xref: watmath net.aviation:1686 net.astro:699 > > If you identify a parcel of air in the atmosphere, and follow it as it > enters a region of temperature/pressure such that its water vapor condenses, > it will become a cloud; yet the mass of the parcel has not changed! > Which is another way of saying that clouds are not something *added* to > the atmosphere, and the mass of air to be moved is not different if the > water is distributed as microscopic drops instead of as gas. > > W. F. Linke Yes, but the volume of that packet becomes somewhat smaller as the vapor condenses to droplets. If you consider that the volume of atmosphere an extraterrestrial object must pass through is constant, then the amount of mass it must displace is thus much greater. -- Marty Shannon UUCP: ihnp4!eagle!mjs Phone: +1 201 522 6063