Date: Thu, 11 Apr 2002 13:44:52 -0700 (PDT)
From: Jerry Friedman 
Subject: Re: (urth) distance


--- maa32  wrote:
...
> 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?

The only possible orbits, once the disrupting force has stopped, are
the familiar ellipses and the parabolic and hyperbolic escape orbits.

> 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.

Gravity doesn't work that way (unless there are other forces, like
those of a spring or a string).

> Would a new gravitational well induce this kind of alteration in an
> orbit?  

Nope.

> Could this continue for a long time, reducing a little bit over time? 

Nope.  Sorry to be so negative, but I really don't see how the Blue-
Green system can work the way Wolfe sketchily describes it, unless
there's some weird solution to the three-body problem that I don't
know about.  Or unless the planets have something like giant rocket
engines on them or a very long cable between them.  (Aha!  Now we
know how the inhumi cross!)
...

Jerry Friedman

__________________________________________________
Do You Yahoo!?
Yahoo! Tax Center - online filing with TurboTax
http://taxes.yahoo.com/

--