An Imperfect Measure

Building requires many measurements, and the numerous building projects discussed and described in the Torah include a great deal of widths and breadths and heights. From Noah’s Ark to the Mishkan (Tabernacle in the Wilderness), the Torah lists amot and tefachim (Biblical measurements) for each part of the project. One particular measurement, recorded as part of the palace that King Solomon built for himself, is interesting for the scrutiny it receives from the sages.

The Book of Kings reports: “And he [Solomon] made the ‘Molten Sea’ (a copper tank used for the priests) of ten cubits from brim to brim around in compass, and five cubits in height and a line of thirty cubits compassed it round about” (I Kings 7:23).

The sages mention the “Molten Sea,”  in a conversation about circumference: “Whatsoever has a circumference of three handsbreadths is one handbreadth in diameter. Whence are these calculations deduced?” (Talmud Eiruvin 14a)  After quoting the text of I Kings 7:23, the rabbis debate the accuracies of these measurements. Rabbi Jochanan set forth the question: “But surely there was [the thickness of its] brim (which would increase the diameter),” to which Rabbi Papa replied: “…But there was [still] a fraction at least? When [the measurement of the circumference was computed it was that of the inner circumference” (ibid.).

The rabbis were aware that the measurement of the ratio of a circumference to its diameter is never perfect. It is, in fact, the irrational, seemingly-unending number of Pi: 3.14159….

And the fact that Pi appears unending is beautiful in its connection to a circle, which has no beginning and has no end and is the Jewish metaphor for the cycle of life.