On Sun, Jul 06, 2003 at 11:19:38PM -0400, David Hobby wrote:

> As I said, I'm not calculating the distribution just now.  It's not
> really a fair tactic to say that I must.

Sure it is fair. The question asked for an equation (or specific
numbers). I gave an equation. You say it is wrong, but don't provide any
number or equations.

> derivative with respect to r is C/r for some constant C.  This is
> wrong, force should go linearly with r.  Right?

Right. I had the wrong potential energy. It should be 0.5m(w h)^2. Here
is the corrected formula for the pressure in the habitat as a function
of height h:

P = P0 exp[ - ( h / R )^2 / ( 2 k T / ( m g R ) ) ]
  = P0 exp[ - ( h / R )^2 / 3.45 ]

So, David, you were right that the pressure is not zero at the
center, but you were wrong about it being constant throughout
the habitat. Pressure is down to about 0.75 atmospheres at the
center. Interestingly enough, it seems Clarke had the pressure being too
low at the center of Rama. So maybe it isn't such a good idea to rely on
a SF book rather than an actual calculation. Of course, it helps to have
someone check the calculation for mistakes....


-- 
"Erik Reuter" <[EMAIL PROTECTED]>       http://www.erikreuter.net/
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