Friday, October 18, 2013

Does God Know Pi?



TL;DR: Yes He does, and it is always best to read in context.


Does the God of the Bible know the value of Pi? 1 Kings portrays the building of the temple under Solomon. Among the sacred accoutrements is a large brass (or bronze) bowl for ceremonial washing. An apparent discrepancy was brought to my attention on an atheist’s blog a few years ago. The passage in question is 1 Kings 7:23And he made a molten sea, ten cubits from the one brim to the other: it was round all about, and his height was five cubits: and a line of thirty cubits did compass it round about.” This verse gives three measurements for the molten sea; a diameter (d) of 10 cubits, a depth of 5 cubits, and a circumference (C) of 30 cubits. Now, any junior high math student knows that the circumference of a circle is Pi times the diameter. Pi is a mathematical constant normally rounded to 3.14159 (if you want a more exact estimate, check this link). Clearly if the diameter is 10 cubits, the circumference should be about 31.4 cubits. Could the Bible, if truly inspired by an omniscient God, portray a 1.4-cubit discrepancy on such an elementary concept? Let’s face it, it’s less than 5% right? But some apologists have tried to grapple with the discrepancy with a variety of explanations, the most creative of which is gematria with the spelling of the Hebrew words. But, as we will see, these kinds of shenanigans are wholly unnecessary.

Before moving to resolve the issue, a little bit on ancient measurements: A Biblical cubit is an anthropic unit equivalent to about 18 inches, derived from the measurement from a man's elbow to the tip of his middle finger. Another such unit is the hand breadth still in use in equestrian circles today, equal to 4 inches. A hand breadth is mentioned just a few verses later in 1 Kings 7:26, “And it was an hand breadth thick, and the brim thereof was wrought like the brim of a cup, with flowers of lilies: it contained two thousand baths.” This verse introduces additional information about the laver, it’s thickness (t).

Could it be that the discrepancy between the diameter and the circumference are made up in the thickness? For this to be the case, the circumference given would be the interior circumference and the correlating diameter should be 10 cubits minus 2-hands worth of thickness. If this is correct, Pi should be found by dividing the circumference by the interior diameter.


C / (d – [2 x t]) = π                                            eq. 1

To make it easy the dimensions are boiled down  to something familiar:

d = 10 cubits = 180 inches
C = 30 cubits = 540 inches
t = 1 hand breadth = 4 inches


and applying equation 1:

 540 / (180 – ([2 x 4]) = 3.139535                  eq. 2

The result is not exactly Pi, but within 0.07%, well within the constraints of significant digits and, dare I say, nothing to squabble over when talking units based on human proportions. That 1 Kings 7:23 is speaking of the external diameter and the internal circumference becomes pretty clear. So, not only does the God of the Bible know the value of Pi but this example can be used as a reminder to look at these things in context before turning to esoteric speculation and desperate rationalization.


 Items for further investigation:
·     The volume for the laver is given later in the chapter, the traditional unit conversions do not match.

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