(urth) The Ship

[Jeff Wilson]

On Tue, January 10, 2012 11:41, Lee Berman wrote:
> Anyway, if the ship was much smaller than the moon it would have to be a
> lot closer
>
> than the moon to Urth to cause an eclipse. I think gravity would become an
> issue,
>
> especially since the Ship would have to remain parked, stationary over one
> particular
>
> spot on Urth for hours (a normal total solar eclipse only lasts a few
> minutes). I
>
> don't see mirror sails being a very effective way of accomplishing this
> and no other
>
> means of propulsion is mentioned.


The mirror sails ("continents of silver") may actually be of a scale
similar to the moon, but they can be microscopically thin so that they
mass less than a walnut per square mile so enough sail to equal the size
of the moon could mass less than a walnut tree.

As for the relative size and distance of the occulting object, the sun and
moon are both about half a degree wide as seen from earth. This means that
the umbra narrows about 1 part for every 200 parts the object is away. An
object like a sail on a long tether could hang 100 miles up and only need
to be half a mile wider than the desired area of totality.

So it may not be "The Ship" in its entirety, but a sail cast off to dangle
and then *poof* when it hits the atmosphere.




-- 
Jeff Wilson - < jwilson at clueland.com >
A&M Texarkana Computational Intelligence Lab
< http://www.tamut.edu/cil >