Repost: π with Jesus

Originally posted March 14, 2017.

It's the second week of Lent, which means that observance has lost its zest. I don't know about you, but I'm yearning for a bit of chocolate. Not a bright, hopeful yearning; a dry, intellectual, arid yearning, because I know I'm not going to eat chocolate anyway. I just want it because it's better than not-chocolate.

So we search for a reason to celebrate, and not the corny-beef celebration of St. Patrick's Day dispensations (which St. Patrick would have disdained) but something rounder, to bring us full circle. And lo! It is Pi Day, 3.14. But we cannot fudge on Pi Day without bringing it into some greater religious context. And not just the context of "God made it, and it is good," because God made chocolate too, and we're not eating that.

Of course, the key question is: would Jesus have known about Pi? Not known-known as God knows all things, but as a person growing up in a first-century Jewish culture, in the course of his human knowledge would he have been likely to encounter the concept of Pi?

Dr. Google offers us thoughts on "mathematics in ancient Israel pi", presenting The Secret Jewish History of Pi:

The relationship between a circle’s diameter — a line running straight through cutting it into two equal halves — and its circumference — the distance around the circle – was originally mentioned in the Hebrew Book of Kings in reference to a ritual pool in King Solomon’s Temple. The relevant verse (1 Kings 7:23) states that the diameter of the pool was ten cubits and the circumference 30 cubits. In other words, the Bible rounds off Pi to about three, as if to say that’s good enough for horseshoes and swimming pools. 

Later on, the rabbis of the Mishnah and the Talmud, who knew that the one-third ratio wasn’t completely accurate, had a field day with the Bible having played fast and loose with the facts, arguing in their characteristic manner that of course it depended on whether you measured the pool from the inside or the outside of the vessel’s wall. They also had fun with some of the Gematria – the numerical value – of the words in the original passage, which when you play around with them a bit indeed come a lot closer to the value of Pi, spelling it out to several decimal points.

"Secret" here might be a bit sensationalistic, seeing as 1Kings is not exactly an occult piece of literature. The Journal of Mathematics and Culture May 2006, V1(1) offers us a more scholarly explanation via Lawrence Mark Lesser's article "Book of Numbers: Exploring Jewish Mathematics and Culture at a Jewish High School":

A value of π can be obtained from I Kings 7:23: 

“He made the ‘sea’ of cast [metal] ten cubits from its one lip to its [other] lip, circular all around, five cubits its height; a thirty-cubit line could encircle it all around.” 

It appears the value of π implied here is simply 30/10 (an error of 4.5%) until a student asks if we need to consider the tank’s thickness -- given three verses later as one-handbreadth, so the inner diameter is 10 cubits minus 2 handbreadths. (Of course, this is also a chance to discuss issues of measurement!) Using the Talmudic value of 1/6 cubit for one handbreadth, the inner diameter becomes 9 2/3 cubits and dividing 30 by 9 2/3 yields more accuracy (error: 1.2%). Applying a more subtle and technical approach to I Kings 7:23 (see Posamentier & Lehmann 2004 or 20 Tsaban & Garber 1998), the ratio of gematrias for the written and spoken forms of a key Hebrew word (for “line”) in that verse is 111/106, which when multiplied by 3 yields a very refined approximation for π : 333/106 (error: 0.0026%). Very few words in the Torah have different oral and written forms. 

By Jewish Encyclopedia [Public domain or Public domain]

Jesus was well versed in the law and the prophets, and it is not a stretch to assume that the account of the building of Solomon's Temple and the fashioning of the great pillars and vessels of bronze was known to him. Could he have known about pi? Could he? Should we doubt his scriptural knowledge? Listen to this.

After three days they found him in the temple, sitting in the midst of the teachers, listening to them and asking them questions, and all who heard him were astounded at his understanding and his answers. When his parents saw him, they were astonished, and his mother said to him, “Son, why have you done this to us? Your father and I have been looking for you with great anxiety.” And he said to them, “Why were you looking for me? Did you not know that I must be in my Father’s house?” But they did not understand what he said to them. (Luke 2:46-50)

Do you not understand? Jesus, in the Temple itself, astounding the teachers with his knowledge and his answers, and talking of his Father's house -- the very house for which the bronze vessel was created*? Even his parents could not understand Pi, as happens with so many parents dealing with their children's math.

My friends. The Scriptures themselves proclaim Pi. Take and eat.

*Not actually the very house, since it was destroyed by the Babylonians in 586 BC, and not the very basin, since 2 Kings tells us that the Chaldeans destroyed it. But still.