Barren sign Barren sign In astrology, a barren sign is a sign of the Zodiac that, according to ancient astrological tradition, is not likely to possess strong powers of procreation, i.e. they are "barren". The signs most associated with infertility are Gemini, Leo, and Virgo. In addition, Aries, Sagittarius, and Aquarius are also believed to quite often have problems in matters of reproduction and are therefore considered "semi-barren". William Lilly (1647) in CHAPTER CXVIII of his book "Christian Astrology" described the signs as follows: Aries: By reason Mars, a sterill planet hath that for his house, and the Sun for Exaltation, is
Zodiac late Antiquity, by which time Ptolemy's influence was widely established. Ptolemy clearly explained the theoretical basis of the western zodiac as being a tropical coordinate system, by which the zodiac is aligned to the equinoxes and solstices, rather than the visible constellations that bear the same names as the zodiac signs. The Hindu zodiac uses the sidereal coordinate system, which makes reference to the fixed stars. The Tropical zodiac (of Mesopotamian origin) is divided by the intersections of the ecliptic and equator, which shifts in relation to the backdrop of fixed stars at a rate of 1° every 72 years,