Why this day ?

Because, Astronomy is the most beautiful discipline that the mankind has ever touched and ancient Indians were remarkably efficient in pursuing it.

Remember the fun-fact that you learnt in school - Sun rises in the east ?

As we will find out, it is not true.

Sun rises somewhat in North-East in Summers (as viewed from Delhi) and somewhat South East in Winters.

In Summers

In Winters

We were also told that there is a path that Sun takes in the day, in which it seems to go from East to West. This happens because Earth rotates on its axis.

This path of Sun is called Ecliptic in modern times. Meanwhile in Indian terminology it is called Rta (ऋता — the cosmic law).

I compiled these videos on Stellarium, which is an awesome open-source software which I use for dating historical events and articles like these.

#loveYouStellarium.

Sun’s apparent path during the course of the day

But interestingly, if we could see the stars in the background, we will notice that it is not the path of the Sun, it is the path of every single star. The whole cosmos goes from East to West.

This is because the Earth rotates from West to East.

Yes !!. It is not just the Sun. Every single star !!.

Sun without sunlight. It is moving with everything actually.

There is another movement that Sun makes across the year. This movement is attributed to the fact that Earth revolves around the Sun. This motion is the reason why we have Sun rising northwards in summers and southwards in winters.

Sun’s path shifts during the months

If you see this movement closely. It looks like a pendulum, with two extremes and one mean position. The two extremes are called Solstices and the means are called Equinoxes. The Equinoxes come in midway of the two extremes. They are precisely on March 21 and September 21.

Equinox is the midway between two extreme positions

We consciously chose the Spring Equinox to mark the beginning of the year.

Fresh air, new leaves, flowers and easterly winds. What else does one need to announce new beginnings ?.

That is why 21st March is the new year for Parsees i.e. Nowruz as well as for all Indian Nationals ( Indian National Calendar ).

But.. Gudi Padwa is on 28th and not 21st March. There seems to be an error. Same goes for Ugadi and Chaitra Shukladi. We even know that dates of these are not even fixed, they change year after year.

To explain that, we bring the concept of Lunar calendar. In most Indian Lunar Calendars the month starts with a new moon (Amavasya).

Hence, we pick that Amavasya, which is nearest to the Spring Equinox.

This way, one also gets to celebrate the new year, but also a new month.

Gudi Padwa | Ugadi | Chaitra Shukladi all fall after New moon, (Amavasya) that stands nearest to the Spring Equinox.

All calendars are approximations in some way or the other. But calendars that follow the natural cycles and resonate with them are elegant. I find that most ancient calendars — Egyptian, Chinese, Indian, Babylonian and Hellenic, all of them qualify as extremely good conventions.

Modern calendar is comparatively a poor convention, but it is the one in which we all find common voice. Hence, respect to that too.

Our calendars are testimony to the attention that our ancestors paid to the skies and stars of far.

In gratitude.

We look up.

And as always.

Stay Awesome.