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Re: [lojban] Compass directions



2011/12/14 Jorge Llambías <jjllambias@gmail.com>:
> On Wed, Dec 14, 2011 at 7:35 AM, tijlan <jbotijlan@gmail.com> wrote:
>>
>> Can "snanu" be defined in terms of other than "berti"?
>
> How about "the direction to your right when facing in the direction in
> which the sun rises (in case you don't want to use "stuna" either).

There are two kinds of south: geological south and magnetic south. The
geological one represents the point where the planet's axis of
rotation meets its surface, also called the south pole. The magnetic
one represents the force field that extends from the planet's inner
core. Magnetic south & north can wander off from geological ones. The
difference creates an angle called magnetic declination, which has
been increasing recently as the Earth's magnetic field is shifting,
causing troubles for airports. Today's magnetic south was north
10,000+ years ago. During a geomagnetic reversal, there can be
multiple souths, looking something like this:

http://upload.wikimedia.org/wikipedia/commons/e/e5/NASA_54559main_comparison1_strip.gif

Sunrise has to do with the axis of rotation, so your suggestion would
work for the geological one, but the other kind of south is
independent of that axis.

Every planet in our solar system has a south pole, but at a different
angle. While the Earth is tilted by about 23.5 degree, Uranus is by
nearly 98 degree -- one pole facing the sun throughout a day --,
resulting in very different conditions for sunrise/sunset (and
seasons).


mu'o

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