There are many parts of life and society that we treat as having some origin in nature but actually came about because some long-dead guy said it was so. The one that trips me up most was my apparently misguided belief that our tradition of counting in base 10 has some mathematically or naturally oriented basis. For those unfamiliar, base 10 means that when we’re counting after we get to 9, we add a digit to the left. If we counted in base 9, counting would be all like “…6,7,8,10,11,12…” Counting in base 3 from what we call 0 to what we call 15 would look like this: 0, 1, 2, 10, 11, 12, 20, 21, 22, 100, 101, 102, 110, 111, 112, 120. But that looks bizarre to us because base 10 is so ingrained into our minds as being the only way in which to count.

Base 10 came into popular use, it is believed, because humans have 10 fingers, which made it natural for them to count in blocks of 10. But if we had 11 fingers, and used base 11, then what we call 121 would be written as a round 100, and the “100-meter” dash sprinters would be a bit more out of breath at the finish line.

Speaking of units of distance, I notice that those too are completely arbitrary in their size. A foot was the length of some guy’s foot. A meter is one ten-millionth of the distance from the equator to the north pole. Huh? A mile, 5,280 of the aforementioned guy’s foot, doesn’t even pretend to have its origin in nature.

Mercury Calendar Birthday PartyA year is 365-ish days because that’s how long the earth takes to circumnavigate the heliosphere, a.k.a. go ‘round the sun. But if we measured years based on Mercury’s sun-circling periodicity, I’d be 135 at the time of this writing, and the birthday cake business would be absolutely booming.

For these reasons, I have trouble getting excited about “significant” birthdays, anniversaries, distances, and really, milestones of every kind. There’s nothing special about turning 50, except that if you take the time since you exited the womb, counted the number of complete axial rotations Earth has made in that time, divided that by the number of axial rotations Earth completes to reach the same position in its orbit each year, then divided that by the number of fingers you have on one hand, then divided that by the number of fingers you have on both hands, you get the number 1.

Fine, I guess that is somewhat cool in the way that -e^(i*pi)=1 is cool, but not in any other way. If anything, base 10 is decidedly unnatural. Computers talk to each other in binary (base 2) or hexadecimal (base 16). Clocks use bases 12 and 24. Musical time signatures are all over the place. Rock music uses base 4, Brubeck’s “Take 5” is in 5, and ballads groove in base numero seis. Pretty much nothing but our counting and accounting conventions use base 10 given the choice. Base 10 feels as natural a phenomenon as morning dew but it is what some guy who has been dead for millennia—millennia!—pulled out of his ass. Or in a more likely scenario, counted on his phalanges.