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The
meaning of the zodiacal
signs. Sundial
List, even
if the zodiacal signs derive from the Babilonian astrology, they were subsequently used to indicate
the Longitude of the Sun (measured from
the vernal point along the Ecliptic). This
convention has been followed by the ancient Greek, from the Islamic scientists
and from the medieval astronomers during a period of hundreds years, from around
the 300 BC till 1400 AD.
According
to this convention the 12 signs are no more joined to the constellations but
only to a value of the Sun’s longitude multiple of 30°. For
instance when the Sun enters in Scorpio it meens only that the Sun’s longitude is equal
to 210° Ptolemy,
for example, describes in the Almagest an observation that Hipparchus made in 127 BC, and he says that the Sun was in Leo at
8°+7/12°, that is that it had a Longitude of (120° + 8.5833°) = 128.5833°.
In
other parts he writes phrases
as “the last degree of Taurus was culminating”, etc. Because
of the precession of the Equinoxes (from Hipparchus around 29.2°), today no
zodiacal sign begins in the constellation with the same name.
For
example the equinox of Aries is in Pisces, the summer solstice in Gemini instead
that in Cancer, the September equinox in the Virgo instead that in Libra, etc.
Finally
the Sun is in the constellation of
Ophiucus from 5° to 25° of
Sagittarius.
I
think that nowadays the lines of the signs are still drawn in sundials not for astrological
reasons, but only to trace the main daily lines (solstices and equinoxes) and to
follow a tradition that has
hundreds of years. Moreover
in the 12 days in which the signs
“begin” the Sun has only 7
different values of declination and therefore the lines that are drawn on a
sundial are only 7, well spaced and arranged almost symmetrically. As
Fer de Vries writes, they are very easily legible. If
we wanted to draw the lines corresponding to the beginning of the 12 months we
would not only have more lines but these would have put in enough confused
way. At
the end, the lines in which the Sun
“enters” in the 13 constellations that nowadays are on the Ecliptic, are even more
chaotic and confused : for example the Sun remains in Virgo for around 45 days
while in Scorpio only for a week.
Best Gianni Ferrari 44° 39' N 10° 55' E |
- The meaning of the zodiacal signs. Gianni Ferrari
- Re: The meaning of the zodiacal signs. Willy Leenders
