Oh, for the ideas of March and apple ‘pi’!

No, not to the approaching winter. I do not love winter as much as the next guy.

I am actually looking forward to spring, or more accurately, the Ides of March. And what, pray, are “Ides?” Let’s check with the Romans.

The Romans were strange. One of them, Romulus, devised a calendar: the Roman calendar. But instead of stuffing it with dates, he named three days of every month. The other days you had to figure out.

The three named days were Kalends, Nones and Ides. But these days were not fixed. Kalends (from which comes our word calendar) was the first day of each month. “Kalendarium” in Latin actually means account book. Since the first of the month was when bills had to be paid, our friend Rommy chose the word Kalends for the first.

Nones was the name given to the 7th day of the month, but only in March, May, July and October. In the other months, it was the 5th day of the month. Go figure. Next up are the Ides: the 15th day of the month. Again, only in March, May, July and October. In the other months? The 13th. Rommy had a system of logic known only to himself.

But wait, it gets better. If you call your doctor, he might give you an appointment for, say, March 4. In the Roman era, he would have said “IV Nones of March.” The Nones of March is the 7th. Now you are supposed to count backwards from that. So IV Nones means you count 4 days before Nones, and come to the 4th (no, my math is not bad; you have to include Nones as one of those 4 days). What about March 6? They called it “Pridie Nones,” Latin for “the day before.”

And these guys were supposed to be smart? I am amazed their empire lasted as long as it did. I guess the general public spent so much time figuring out which day of the month it was, they had no time or energy left to rebel against the Emperor. Or if they did, they might have missed the date of the coup. The Ides of March is the 15th, while the Ides of April is the 13th.

So, anyway, I am waiting for spring, and the Ides of March. When thoughts start turning to renewal, to baseball, and to National Pi Day. Which of course is on March 14, as decreed by the U.S. House of Representatives. This, incidentally, is also Albert Einstein’s birthday.

So what is pi (or π, as the Greeks insist)? It is the ratio of the circumference of a circle to its diameter. The circumference is the distance all around the circle, and the diameter is the distance from edge to edge, measured through the center of the circle. Pi is a fixed ratio, with a value of 3.14159, give or take a little.

Interestingly, even the Egyptians and the Babylonians knew about pi, and believed that this ratio was a little bigger than 3. In the 3rd century BC, Archimedes the Greek came up with a number between 3 1/7 and 3 10/71. Then the Chinese jumped in, Mr. Zu Chongzhi declaring in the 5th century that the ratio was closer to 355/113.

So why this fascination with pi? It has an infinite number of numbers to the right of the decimal point: 3.141592653 … and so on, with no pattern to these numbers. We have worked out the value of pi to 10 trillion digits. “We” meaning a Japanese guy called Mr. Shigeru Kondo, with no help from me whatsoever.

The extra fascination next year is that on March 14, 2015, at 9:26:53 a.m. and p.m., the date and time will have the first 10 digits of pi, namely 3.141592653.

So let us celebrate the Pridie Ides of March next year by thinking of Einstein, enjoying some apple pie and thanking God that we don’t have to write out the value of pi in Roman numerals.