Date: Tue, 09 Apr 2002 21:29:13 -0700
From: maa32 
Subject: (urth) distance

Well, Blattid, since you put it so succinctly, the choice is easy.  Of course 
the 30,000 league figure is incorrect!  Which means that Green might only 
fluctuate a tiny amount from its 80,000 league distance, which is where the 
moon is in our day.  Of course, this means that the inhumu have to fly a long 
way, but that's cool with me (after all, that tree ship can fly a long way, 
too - and I don't think they are much different).

And this distance, closer to 80,000, wouldn't screw up the tides as much and 
wouldn't seem to be such a weird system; it might just fluctuate a little bit, 
like a moon in a slightly unstable orbit due to recent gravitational 
disturbances.  In this case, a new sun coming. Sure, let's say that Green is 
at 60,000 leagues at conjunction, making it ... about the same size as Lune.

Thanks!  You made everything so much easier!  So we know that the moon was 
moved from about 80 to 50 thousand leagues in Severians day ... a fluctuation 
of about 30 thousand leagues ... if a new gravitational vortex where to 
disrupt this system, would the moon act like a gyroscope and oscillate in and 
out of orbit, first close and then far, between 60 and 100 thousand leagues, 
until it reached a stable orbit somewhere around 80,000?  Like an old 
fashioned weight scale: you step on it, and then it goes back and forth until 
it reaches equilibrium, and equal distance on the up and down swing until 
there is no perceptible movement.

Would a new gravitational well induce this kind of alteration in an orbit?  
Could this continue for a long time, reducing a little bit over time?  Also, 
let's keep in mind that the moon is proportionally very large for a satellite 
when compared with the earth's mass.  It is huge compared to the satellites of 
most of the gas giants.

I hereby gladly revoke my uncritical acceptance of 30,000 leagues.  You guys 
were so right; that figure sucks. That astronomer is one shady dude!
Thanks.
Marc Aramini



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