II. The Identity Crisis
The well known American scientist/astronomer Carl Sagan defines astronomy as "a science - the study of the universe as it is" and modern astrology as "a pseudo science - a claim, in the absence of good evidence, that the other planets affect our daily lives." He goes on to say, "in Ptolemy's time the distinction between astronomy and astrology was not dear. Today it is. Modern astrologers have forgotten about the precession of the equinoxes, which Ptolemy understood."
In the science of Jyotisha, astronomy is included as one of the three broad divisions know as: Siddhanta, the purely astronomical study of universe; Samihta, the study of how the stars of astronomy relate to world events and how to fortell them; and finally Hora or Horoscopy (derived from Ahoratri meaning "the science of day and night"), the knowledge of how to determine the positive and negative karma of a soul accumulated in the previous birth from the position of the stars at the moment of this incarnation.
Mr. Sagan seems to be unaware that Hindu astrology does account for the slow backward movement of the equinoxes. When Westerners first approach Hindu sidereal astrology they notice this adjustment as a difference in their Sun sign. An immediate identity crisis is experienced upon finding out they are actually a Pisces instead of Aries, or Virgo instead of Libra. At this point the Hindu astrology book is either thrown in the trash so life can continue as an Aries or the previous identity is renounced to dive head first into the ocean of Jyotisha.
As all astronomers and Hindu astrologers know the Sun actually entered the constellation (pattern of stars) of Aries on April 14th this year, not March 21st as believed by most Western astrologers. The apparent division between astronomy and astrology which Mr. Sagan suggests with scientific enthusiasm, only exists in the Western tropical astrology, primarily because it no longer uses the actual fixed constellations of astronomy. This is not to say that the tropical system has no use, only that it is very limited, dealing with mundane matters and the external mind. Tropical astrologers are somewhat vague as to what does cause their zodiac to exist. The zodiac (derived from zoo since the signs are named after the constellations, many of which are animals) is defined as a broad band in the heavens circling the earth extending 9 degrees on both sides of the ecliptic The tropical zodiac seems to be based on the energy aura of the earth and the Sun. This is why in tropical astrology the dates can be fixed for when the Sun enters a zodiac sign each year, similar to the regular seasons occurring as a result of the earth's revolution around the Sun. But in Hindu sidereal astrology the zodiac (known as the Bhachakra - wheel of lights) is based upon the emanations coming from the groups of Suns or Star systems which form the major constellations of astronomy, and these as Mr. Sagan points out are also moving, causing the zodiac to shift very slightly each year. Actually it moves at the very slow rate of one degree every 72 years. This is known as the precession of the equinoxes and is corrected for in Hindu astrology by a calculation called the ayanamsha.
Twice a year when the Sun crosses the equator it creates for the Earth an equal time of night and day. These are known as the Vernal Equinox (in the spring) and the Autumnal Equinox (in the fall). It so happens that each year this occurs slightly earlier than the year before in relation to the fixed constellations. To be more precise, the position of the Earth in reference to a fixed star is about 50 seconds of space farther west than it was the previous year at the equinox date. This doesn't seem like much, but over the years it adds up. In approximately 2,160 years it has moved back one whole constellation. This accounts for the difference in your tropical and sidereal Sun signs. At one point in time (which no two astronomers or astrologers have agreed upon) the Vernal Equinox on March 21 occurred when the Sun was in the fixed constellation of Aries. The tropical sign and the sidereal sign were the same and everybody was happy. Now the Vernal Equinox is occurring when the Sun is in the constellation of Pisces, but most Western astrologers still say that the Sun enters Aries each year on March 21! No wonder Carl Sagan gets hot under the collar when somebody asks him what sign he is.