Via a retweet from David Whitewolf we have this:
6 x 5 x 2 minutes in an hour
8 x 3 hours in a day
7 days in a week
So every month has 8 x 7 x 6 x 5 x [# of weeks] x 3 x 2 x 1 minutes in it.
So there are 8! minutes in February.
Except, of course, on leap year.
This is incredible. This has to be a coincidence. Right?
Not nearly as cool but also fun: two weeks is very nearly a million seconds. I once worked on software where — for geek humor — various time limits were documented as numbers in units of “microfortnights”.
I remember once reading about how the English measures were related to the diameter of the Earth. I can’t remember what that relation or ratio is. . .
The French “meter” was intended to be 1/40,000,000 of the Earth’s circumference. A surveying expedition was sent out to make it as exact as possible. (It’s actually pretty close.)
Also by design: metric system units are all interrelated. 1000 cubic centimeters is exactly one liter; one liter of water weighs exactly one kilogram. Don’t try that with inches, quarts, and pounds!
Yes, that’s the design of the metric system, though the actual units did not come out precisely that way and aren’t defined that way. They pretty much match the design to the precision available around 1790. But, for example, the meter is defined in terms of the speed of light; the kilogram is defined as the mass of a piece of platinum/iridium alloy sittings in a vault in Sèvres (BIPM headquarters).
BTW, the liter isn’t officially a metric unit.
“… the actual units did not come out precisely that way and aren’t defined that way.”
Have the Europeans stopped fiddling with the Metric System yet? They have “adjusted” it any number of times since they started it.
At one point, I had 4 torque wrenches in different metric systems. A machinist pointed out that if you are looking at non-current designs, you had better be VERY careful about measurements in documents, as they will be merely approximations, and in no way considered to be accurate today.
Consider the source. They are socialists, and facts are malleable in their thinking.
It sounds like you’ve been talking to people who have no clue. The metric system has grown over time — originally electrical units were not part of it, which they now are. But the units have never changed, within the limits of accuracy of the time. “Different metric systems” — that makes no sense. Not unless those devices were marked in pseudo-metric units like “kilogram-meter”. The metric unit of torque is newton-meter (Nm).
The definition of units has changed over time, but that didn’t change the value, it only changed the way in which you would realize the unit in the lab with the greatest accuracy. For example, at one time the meter was defined as the length of a metal bar; then it became the distance between lines on a different metal bar; then it became a specified multiple of the wavelength of a certain light source; finally (as of now) it ended up defined as the distance traveled by light in a stated fraction of a second. But that didn’t affect the number.
If you want to see variable units, consider the inch, which came in three flavors: US, Canadian, and British. The currently used one (25.40000 mm) is the Canadian one, except that the US still claims to have a “survey inch” which is the old US inch, slightly different from the regular inch. (Whether that supposed difference is real is debatable; gauge blocks were only ever made in 25.4 mm inches, even before that consistent definition was made official.)
Measurements are of course always approximations, and if you’re using measured values, you need to understand the tolerances involved in the measurements (whether stated or not). That has nothing to do with the system of units used — not unless that system is itself inadequately defined, as was the case with the US/Canada/UK system in the past, or the hundreds of different pre-metric systems once used in Europe.
The Mayans used a system with ones, fives, tens, and twenties, composed of dots and lines. And their year had a five day uncertainty at the end, when one had to be careful to avoid offending the gods, lest the year not renew and the seasons start again.