Re: CONCULTURE: dual planets

Rodlox scripsit:

>  so, even when part of one world is facing the sun (say, New York), it'll
> still be having night-time, since the second world might be between the
> first world and the sun.   if they are
> tidally-locked/geologically-syncronized or some such, some parts of the
> world would be almost polar in their day-night cycles, experiencing "day"
> only when the two worlds are *both* side-by-side & exposed to light from the
> sun.
This wouldn't be true of the Earth-Moon system, even if the Moon were nearly
as big as the Earth, because the Earth-Moon system is tilted over about 23
degrees.  This is why we only have 2-5 solar eclipses per year, Earth-wide,
and about the same number of lunar eclipses.  For the Moon to be between
the Earth and the Sun, it has to be not only dark, but also crossing the
ecliptic (the line in the sky that the Sun appears to move on in the course
of a year).

A bigger Moon would mean longer eclipses, but not more of them.

--
John Cowan                              <jcowan@...>
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