[Groop] re:re:re:re:re:reguarding: highest poster

Chris Schechner chschechner at ev1.net
Thu Apr 14 19:02:11 PDT 2005


Pardon me while I sit here and drool out of the corner of my mouth.

on 4/14/05 8:36 PM, Eric Chun at ericchun at hotmail.com wrote:

>> Yeah, but what's "up" in space?
> 
> Directions in space are a little more complicated than directions on Earth.
> On Earth, we have a whole planet that helps us give directions. In space,
> we don't have a stable surface, so new directions had to be invented.
> First of all, the equivalent of up and down on Earth is elliptic north and
> elliptic south, except that elliptic north is defined as the direction
> tangent
> to the Earth's orbit, in the direction that the Earth is rotating around the
> sun. Elliptic south is the opposite direction. The four directions
> correspond-
> ing to north, south, east, and west are summer solstice, winter solstice,
> spring equinox, and fall equinox. To determine where summer solstice is,
> you start from elliptic north and go straight towards the axis of the
> Earth's
> rotation, passing it until the line from the center of the Earth going to
> you
> is perpendicular to the elliptic directions. The opposite direction is
> winter
> solstice. To determine fall equinox, you look straight down elliptic north
> and go 90 degrees counter-clockwise. Spring equinox is in the other direc-
> tion.



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