(urth) Cumaean???

[Jeff Wilson]

Pedro Pereira wrote:
> 
>  >
>  > Recursive Loop wrote:
>  > > "Lune is a tricky subject. We know it LOOKS bigger than now. That 
> may be because its closer. Why
>  > > its closer we don't know. Maybe Wolfe assumes it would be closer do 
> to gravitational attraction,
>  > > but thats wrong, because the Moon is actually getting farther away 
> from Earth. Maybe it was
>  > > intentionally "pushed" towards the earth? Why I can't possibly 
> understand. Some people say that
>  > > its mass was increased. Maybe, but what for and how?"
>  > >
>  > > If it were terraformed, they might have pelted it with comets to 
> build the atmosphere. That would
>  > > increase the mass. But they also might have pelted it with rocky or 
> metal asteroids to build the
>  > > mass (and increase the gravity) to help retain that comet-pelting 
> created atmosphere (speculation
>  > > here).
>  >
>  > Lune may look bigger because it is closer. "...the green, reflected
>  > light that fell from the myriad leaves of the Forest of Lune, fifty
>  > thousand leagues away." (if an Urthly league is still three miles long,
>  > that's 150,000 miles, or 3/5 of the current distance.
>  >
>  > The moon may not be strictly terraformed, as it is not massive enough to
>  > retain useful atmosphere, and there are not enough asteroids or
>  > observable comets to make it so.
>  
> What about in the asteroid belt? 

As I said, there are not enough asteroids to do so. At best, they add up 
to about 30% of the moon's mass.


> We are talking about galaxy spanning 
> ship technology. I don't think there would be much a problem to increase 
> the moons mass to a point where it could retain an atmosphere.

It would be on the same order of magnitude as moving Urth herself.

However, this mass increase would disastrously increase the tides on the 
earth. Increased its mass by 8 times to that of Mars would increase the 
tidal forces by 8 times as well, and still only retain a few millibars. 
Also, moving the "moon" closer by 3/5 would increase the tidal forces by 
  the inverse fourth power for further multiplier of about 7.7. Goodbye, 
Bay of Fundy!


> It may be be covered with greenhouse
>  > domes, or anything else green-colored, making the Forest of Lune as real
>  > as the Swamps of Venus were.
> 
>  
> I believe that Wolfe's idea is real forests on Lune, dome-free and 
> covering the whole place (at least a big portion of the side facing us).
>  
> On the other hand this would lead to a study on how much mass would be 
> needed, at what distance the moon is, degree of compaction of the new 
> added mass, etc, etc. just to know exactely how big the moon appears. 
> Thats why stuff is left deliberately vague in many cases. I honestly 
> don't think Wolfe gave himself all that trubble. He takes great care 
> with what he does as a writter, but he's nor perfect.

The issues I mention above were all well represented in SF and popular 
science before 1980, no special study would be needed.

-- 
Jeff Wilson - jwilson at io.com
< http://www.io.com/~jwilson >