Happy 2010, or so

Today we turn over another digit in our year numbering. It is rather arbitrary — purely a chance of how many fingers we have that prompted us to adopt a base-10 numbering system — but we give it some extra significance.

If we’d happened to’ve had six fingers per hand, and we thus used a duodecimal system, we’d call this year 1-1-11-6, or 11B6 if we say A=10 and B=11. Of course, we’d actually have digits for 10 and 11 in that case. Anyway, it would be another six years before we’d turn over a digit — two digits, in fact, in the year 1200 (decimal 2016). In hexadecimal (base 16), we’d now be starting the year 7DA; in octal (base 8) it would be 3732.

How we count the years — when we start the count, and how long the years are — is also arbitrary (though the year length does need to be approximately the same in the long run), and there are differing versions. By Jewish reckoning, we started the year 5770 back in September. The Islamic calendar had us entering 1431 two weeks ago. In the Persian calendar the year is 1388, and we’ll start 1389 at the vernal equinox, 21 March. And the Chinese will welcome the Year of the Tiger on the 14th of February — there’s no firm starting point (epoch), but a common one will have us in the year 4707.

And in the now-dead Julian calendar, in use in Russia until 1918, today is still the 19th of December, 2009; the Julian new year won’t happen until what we now call January 14th.

In any case, most of us in much of the world look at this as a notable day. And so it is now noted in these pages. I wish everyone a happy, healthy, and prosperous 2010.

Update, 2 Jan: The 360 blog has this post about interesting things related to the number 2010. And 360 points us to this similar one from MathNotations.