[SPAM] Re: Why doesn't the sky fall?

[randy10926 at comcast.net]

Even in the bottom half of the atmosphere the density of air is so low that it is mostly space.  But even at this low density - on average an 'Air molecule' collides 5 times a nanosecond.   'Air Molecule' is a generalization for the air mixture which contains O2, CO2, H2, etc.  Some particles are molecules, some atoms, some ions, some ad nasuem.    The generalization is used to develop mathemical or computer models of the atmosphere.

And at the size of an 'Air molecule'  we are starting to get in the areana where just plain old classical physics has some problems and other forms of physics are introduced to help explain what is going on.

randy

-------------- Original message -------------- 

That probably explains why I smell it so fast when somone lights a match in the house.

BTW, I don't think there is an "air molecule", it is a gas mixture and it is packed rel tight on the bottom. Half of the atmosphere is below 18,000 feet. 

John Ferrell    
http://DixieNC.US

----- Original Message ----- 
From: randy10926 at comcast.net 
To: discussion at nsrca.org 
Sent: Monday, August 15, 2005 5:22 PM
Subject: Re: Why doesn't the sky fall?


Air molecules are never at rest. They undergo constant random thermal motions of a variety of types. The simplest type is that of uniform translation. The mean speed is about 500 m/s which is greater than the speed of sound (340 m/s). 

Randy

-------------- Original message -------------- 

I thought it was time to stir the pot while we wait for the results from the Worlds.
Can anyone explain why gravity doesn't pull all the air molecules down to earth?  Are they lighter than space?  What is their mean speed?
I don't think this will help answer the weathervaning question and won't help us fly any better but I thought it might be fun.
Jim O
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.f3a.us/pipermail/nsrca-discussion/attachments/20050816/954ef1a0/attachment.html