Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84 exptools; site iham1.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!iham1!jgpo From: jgpo@iham1.UUCP (John, KA9MNK) Newsgroups: net.aviation,net.astro Subject: Re: Something else to watch out for! Message-ID: <377@iham1.UUCP> Date: Mon, 24-Jun-85 10:13:16 EDT Article-I.D.: iham1.377 Posted: Mon Jun 24 10:13:16 1985 Date-Received: Tue, 25-Jun-85 07:46:17 EDT References: <11270@brl-tgr.ARPA> <1199@phoenix.UUCP> <1679@amdahl.UUCP> <122@shell.UUCP> Distribution: net Organization: AT&T Bell Laboratories Lines: 29 Xref: watmath net.aviation:1667 net.astro:689 > > I can't imagine how hitting a cloud layer - no matter how > > dense - would be like hitting the ground (even at meteoric speeds). > > I remember from ground school that air filled with water vapor is > less dense than dry air, even though is feels "heavy". If clouds > are water vapor, doesn't this make them *less* dense than the > surrounding air? Unless there was a storm in progess with > condensed water, I guess. > > A. Lester Buck > {ihnp4, pur-ee, ut-sally}!shell!buck Clouds aren't made of water vapor. They are made of minuscule water droplets. Don't forget that water vapor is invisible. You begin to see clouds when vapor-laden air rises to a point where it's cool enough for the vapor to condense. You're right that moisture-laden air is less dense than dry air. The picture changes when the water vapor condenses. Then you've got a bunch of droplets hanging around, and that's a heck of a lot of mass for a meteor to try to push out of the way. Don't forget that water (and air, if you're going fast enough) is incompressible. John Opalko AT&T Bell Labs Naperville, IL ihnp4!iham1!jgpo