The science of the
Tamil new year
One year is the time taken by the earth to go around the sun. When defining it that way we have to consider the centre of the earth.
Speed of the earth around the sun is about 30km/sec. So if you are going to take a point/country on the surface(and not the centre) of the earth there will be 24 hrs difference between the times of New year celebrations on the adjacent points west and east of the international DATELINE. In 24 hours earth would have moved 24 X 60 X 60 X 30 km (2592000 km), which means one full round about the sun by the earth becomes meaningless if you consider any point on the surface.
Moreover 365 days is an approximation and assumes that the circumference of earth’s orbit is exact whole number times of its own circumference.
The ancient man could have arbitrarily taken one year as between subsequent spring/summer/winter times or as between any events that are annual in occurrence. It would have really been a convenient method for him to determine ages of living things. But for the present day scientific man, precise determination is needed.
There is a mathematical method of determining an year. Go to your roof top in the night, with a hollow cylindrical tube. Observe a star through the tube. Fix the tube in that position and note the time. Say the time is 9 pm. The next day the same star will be seen through the tube at roughly about 8.56 pm. The following day at 8.52 and so on. When the star could be seen through the tube again at 9 pm, it would be exactly one year from the time we started. This is based on the assumption that the stars are at infinite distance from the earth, so it makes little difference from wherever you make this calculation.
Our ancestors did just that. But instead of hollow tube mentioned above, they noted the entry of the sun into a zodiac sign; the constellation of Aries.
Now let’s see how the concept of constellation came to be. The earth rotating about its axis is the real happening. The sun, moon, stars and all going round the earth in 24 hours is the relative happening, which we see. The earth moving (rotating) from west to east is the real happening, all celestial objects rising in the east and setting in the west is the relative happening. Calculating movements according to relative happenings will yield as good results as when it is done in real happenings. It is like assuming the platform moving backwards as the train goes forward and carrying out your calculations.
The Earth is assumed to be at the centre of the universe. Then all celestial objects, the sun, moon and the stars appear to be on a big sphere with Earth as its centre. This is an apparent sphere of course. But we can assume it and do some mathematical observations. In astronomy this is called the celestial sphere. Relative to the earth’s rotation around its axis the celestial sphere, with all celestial objects in it, would be making one complete rotation around the earth, in the opposite direction, in 24 hours. The axis of rotation will be the same as that of the Earth. Corresponding to the earth’ poles we will also get celestial north and south poles at the points where the earth’s axis meets the celestial sphere.
On this celestial sphere the stars are fixed in their positions. You may have read that stars are really not stationary but in constant motion. But their distances from us are immeasurably great and their motions relatively very diminutive that they have a fixed position on the celestial sphere. Since their positions are fixed we can imagine many shapes among the stars by joining them. These are called constellations.
The whole celestial sphere is divided into 12 equal stripes. Each stripe will have a range of 300 on sky. These stripes are named after the main constellations found in them. These are called the zodiacs. Hence we will get 12 zodiacs viz. Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces.
On the celestial sphere the sun and the planets will be seen to move through the stars in west -east direction. The Sun will go through all the zodiacs in an year, at the rate of 1 zodiac per month. Our ancestral wise mathematicians decided the entry point of the sun into the zodiac sign of Aries as the beginning of the year, since this takes place in the beginning of summer.
This takes place between 13th and 15th of April and is called the Chiththirai Varudap pirappu, Chiththirai being the Tamil name for April. Aries is preceded by Pisces. Since the New year is defined as the entry of the sun into Aries, the eastern most point on the disc of the sun coming into touch with the line of demarcation between the zodiacs Pisces and Aries will be the exact time of the beginning of it.
This time would be for the earth, the whole world. It would apply to every country, each in relation to its time zone. Suppose the New year begins at 1:55 pm, Tuesday 14-04-2015 in Colombo, Srilanka, time in London would be 09:25 am, Tuesday 14-04-2015. At Honolulu, Hawaii, USA it would be 11:25 pm Monday 13 – 04- 2015. It is the same moment for all these places.
We all know that the movement of the sun affects the climate. The seasons spring, summer, autumn and winter are due to this. There are frequent changes in the tides of the seas. The resultant gravitational pull of the sun and the moon as the latter goes round the earth is the said to be the cause of this. Climate affects the behaviour of all living things including human beings. Besides the sun and the moon, the rest of the planets as well affect a number of happenings on the earth.
Natural settings affect our behaviour. Our present behaviour and experience is going to affect our future outlook. Based on this ancient wise men evolved the science of Astrology.
In astrology the effects of the two big planets, namely Jupiter and Saturn are regarded as important. Jupiter goes round the Sun once in twelve years. From the earth it will appear to be in each zodiac every year. Saturn goes round the Sun once in thirty years. From the earth it will appear to be in each zodiac every 21/2 years.
L.C.M. for 12 and 30 is 60. So once in every sixty years both these planets will be seen in the same zodiac. Hence the combined effects of Jupiter and Saturn will have 60 variations on the earth. Accordingly a cycle of 60 years is recognized and they are named. That is how each Tamil year gets its name.