[extropy-chat] Astronomical question

[Dan Clemmensen]

spike wrote:

>>How are we going to get the moon to rise over the horizon when
>>we are tide-locked?
>>    
>>
>
>Doh!
>
>Well wait.  You get in a plane and fly east starting from
>the no-moon side of the earth.
>
>spike
>
>
>ps Dan, hows that for a recovery from a goofy mistake?  {8^D  s
>  
>
Not bad at all. I struggled to find something more romantic before I
gave up and asked you for help. I think a balloon would be more romantic
than airplane, but consider that we won't tide-lock for at least a billion
years. Under the circumstances, we should come up with something involving
mega-engineering that allows for a moonrise in a tide-locked system. Perhaps
we can orbit a really big mirror and watch as the moon's reflection rises?

Simpler might be to cheat. After the earth earth's very last rotation 
with respect
to the moon, but before is settles down, the system will have 
transferred all the
angular momentum. But the earth will wobble after that until it finally 
locks. The
moon wobbles in this fashion, in a movement know as nutation. So, just 
after the
last rotation, there will be very large nutations which should allow for 
moon rises.