## Superfluous Accuracy

I heard that the Great Pyramid is lined up North/South to within a tolerance of something like a ten-thousandth of a degree. Wow, those Egyptians were good. See Pi and the Great Pyramid.

But, any scientist would say, "Give me a break." That kind of accuracy tells more about the measurer than about the thing that he is measuring. That kind of accuracy is what is sometimes called "superfluous accuracy." There isn't any stone or group of stones on that pyramid that anyone can measure whether it's lined up in any direction to within .0001 degree.

Besides, I wonder how far that part of Africa has rotated in a few thousand years, not much actually, but more than .0001-degree?

Let's generate a little superfluous accuracy on our own. I'm 6-feet tall. How tall am I in centimeters? Well, there's 2.54 centimeters in an inch, exactly. So, I'm 182.88 centimeters tall. How about that? All of a sudden, my height has been measured to within a hundredth of a centimeter. That's pretty accurate, not quite as accurate as they measure pyramids, I'm sorry to say. But wait a minute, I've never been measured that accurately. Where did all that accuracy come from? It actually comes from the fact that we are throwing away estimates of error. I should have said "I'm 6-feet tall (plus-or-minus .25 inches)." Then I would have to convert the plus-or-minus .25 inches, along with my other calculations.

Perhaps the classic example of superfluous accuracy is the calculation of the age of the earth by the Bishop Usher, using the genealogy given in the Bible. He claimed that he had deduced the age of the earth, to the day (October 22, 4004 BC). Wow, his Bible was a lot more accurate than mine is.

The Bible gives the age at which each firstborn son had his own firstborn son. This implies a chain of dates that goes back to Adam, about 6000 years ago. All of these ages are given in whole numbers of years. None of these ages is given in minutes. Did the Bishop Usher think that all of these people were born on January 1 (or whatever day was the first day of their year), at 0:00 o'clock?

When you see a claim of accuracy like that, just say, "Give me a break."