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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
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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