Chasing the Greek Foot
Somewhere along the line I was trying to find out how they properly located things on the planet, that led to geo – metrology, that lead to the fact that the Greeks and Egyptians had a measure named a ‘foot’ (pous) that is almost the same as the English foot. (Within a couple of mm 304.8 for the Engish, 304 mm for the Minoan, 308.4 for the Attic, 300 for the Egyptian and Phoenician, etc.)
This lead me to the factoid that if you take the earth’s equatorial circumference in ‘feet’ (English) as 131479724.6 (from the wiki metric number, converted) and divide it by 360 x 1000 (call it 60 minutes x 60 seconds x 100 or call it 360 degrees x 1000) you get: 365.2214573
Gee, that looks familiar, I think… Dividing by ‘tropical year days’ of 365.2422 gives 99.994% agreement. Hmmmm….
(If the English foot were 304.7828 mm, which rounds to 304.8, the agreement would be 100.0000% which is inside the error band of 304.8 so it is possible that the original English foot is exact and the metric conversion is not precise enough to capture that…)
Numerology? Or did those Ancient Greeks & British Druids know something? Is the ‘foot’ perhaps a bit more rational than mythology asserts?
One can only hope that the Met Office can achieve 99.994% accuracy and that GISS can learn what those digits after the ‘point’ are all about… (“Never let your precision exceed your accuracy”…) and maybe that we can be as good at science as they were 4000+ years ago…
(BTW, you can derive the “foot” using a bit of string, two sticks, and the night sky… but maybe you ought to work it out for yourself… Hints: 1) Make a time standard using a celestial object transiting the two sticks. 2) Make a pendulum tuned to the time standard. 3) Measure the pendulum… You now have a very scientific time standard and distance standard that can be recreated by anyone anywhere. Think about it…)
FWIW, the European / Scientific tendency to change perfectly clear units into things that honor some guy or other but hide their physical truth is just nuts. It turns more kids off to science than anything else. Why have Hz when cycles/second TELLS you what it is? Compare a “Pascal” to a “pound per square inch”. There is no clue what a “Pascal” is… which is probably why my tires have kg/cm2 on them.
So I, for one, will be happy to use feet (that have a history going back to before recorded history, being nearly identical to the Minoan foot… and having nothing to do with human feet) pounds per square inch and yes, F for decades to come. Though from time to time I will use Centigrade (a name that tells you something…) for some uses (my car, for example, is calibrated in C ).
And NOAA ought to retain F so as to retain the integrity of the data series (which seems to me to be a valid scientific reason – unless of course you want to recalibrate every single site for the change of equipment…)