What's with the obsession for meters?
But that's neither here nor there. Using football fields as unit of measurement is odd. You don't see metric countries resorting to using soccer pitches as unit of measurement.
Unfortunately Germany does.
This is not a argument for the size of a meter itself, it's simply noting that we've made a system of related measurements using base 10. We could get the same result using "football field" as the base unit of length and make 1 cubic football field equal to 1000 "swimming pools" (volume).
You know, the precise definition in use for 129 years since 1893 .. the one used to ensure one measured "foot" matched another . . .
More interesting, maybe, is the length of the Dynastic Egyptian cubit: pi/6 meters, 52.36cm.
So, measure the Great Pyramid's King's Chamber: 10x10x20 cubits, exactly. Or, as exactly as the Egyptians could manage, somewhere between 3 and 4 significant digits. Very precise, for masonry.
That is thus 5.236x etc. meters. But 5.236 is also, by divine coincidence, 2phi² = 2(phi+1), and also, by even more blessed coincidence, 5pi/3, to five significant places, closer than the Egyptians could measure.
(Recall, phi = (sqrt(5)+1)/2 ~ 1.61803... pi ~ 3.14149265...)
So the King's Chamber, measured in meters, but only in meters, is both 2phi² meters and 5pi/3 meters wide. (Or 5tau/6, if you prefer.) And, of course, twice that long.
Some people are bold enough to suggest that when the meter's length was chosen, the guff about Earth's circumference was a shuck. By another divine coincidence, the Royal cubit of France was also 0.5236 m, equal to the Dynastic cubit, and the corresponding "span" (equal to 1/phi² cubits) was exactly 20 cm.
At the time the meter was defined, the French had not yet invaded Egypt. Could a masonic tradition preserve ancient measure through two millennia after the last dynasty?
Some people insist the diagonal, from one corner of the chamber to its opposite is special. But it is just 10sqrt(6) cubits, or 10.00+2sqrt(2) meters... to three places. Another coincidence.
Numerology is all fun and games today, but to the ancients it was all deadly serious business.
I feel like this might be slightly retconned to fit nicely. From what I've read the Egyptian cubit sticks actually varied in length by a couple of centimeters.
You do have to calibrate to the King's Chamber cubit, which seems defensible. But the numbers do check out: 2phi²/(5pi/3) = 1.000015 is pretty trippy, no matter how you slice it. Likewise 5sqrt(6)pi/3-2sqrt(2) = 9.997.
There's no denying the ancients would be impressed with that sort of thing. Maybe even Newton, too. Of course, none of this proves the Egyptians knew about any of it.
Probably the lesson for us is that numerical coincidences are way more common and less significant than we are inclined to think.
[Also: pi ~ 3.14159265...]
All the same, telling people that the USofA was one of the very first adopters of the SI metric system and still bases all its measures on metric will get you a few odd looks.
"The pulse is 1.6 plasma wavelengths long", "the shock front is on the order of 2 laser wavelengths thick", etc
SI dimensions (again, in my sub-field) were treated more as a manufacturing spec for experimental equipment than as a convenient way to discuss phenomena or a good way to communicate the size of something with someone else in the field.