Another fun fact dating from French revolution is the 10 hour-day, each hour had 100 minutes and each minutes 100 seconds : <a href="https://historyfacts.com/world-history/fact/france-had-a-calendar-with-10-hour-days-during-the-revolution/" rel="nofollow">https://historyfacts.com/world-history/fact/france-had-a-cal...</a>
> (It was later found the astronomers were a bit off in their calculations, and the metre as we know it is 0.2 millimetres shorter than it should've been.)<p>That's actually impressively good accuracy for the time! Hats off to the astronomers.
I always think about what a cool adventure it must have been, for Pierre Méchain and Jean-Baptiste Delambre to roam for 7 years, go wherever they need thanks to an official letter, make calculations and come back successful to Paris. To think that they were only off by .2mm !
Here's a completely random anecdote: my mother often told me that her father, my grandfather, born in France in 1899, sculptor, draftsman and general maker of things, had a strong dislike of the metric system. He complained continuously that anything with round metric ratios was "ugly" and that beauty could only be found in more ancient measuring systems.<p>He died when I was 4 so it's not a first hand account, I'm not sure how much of it is true or what he really thought, but somehow it feels right.<p>The metric system is incredibly useful and practical (of course) but there's something rigid and unpleasant about it.
Things that annoy me about the metric system: base-10 numbering system, a liter is not a cubic meter, and 'kilogram' is the base unit, not 'gram'.<p>That last one is what I have the biggest problem with. When you are doing anything with derived units, 'kilo' suddenly disappears.
> From 1983, a metre was considered the distance that light travels in a vacuum in 1/299,792,458 of a second (because light travels 299,792,458 metres per second).<p>So the speed of light was calculated using a previous definition of metre, and that magic number was used to upgrade its own definition? That's a tautology, sounds wrong to me.
“It fell to a pair of astronomers to calculate this distance, and after seven years, in 1799, they presented their final measurement to the French Academy of Sciences which made a "Metre of the Archives" in the form of a platinum bar.”<p>What unit did they use to measure the length of the platinum bar?
The meter wasn't invented during the French Revolution, it evolved from ancient measurement systems based on the golden ratio.<p>Traditional body measurements (thumb, palm, span, foot, cubit) follow a Fibonacci-like progression where each unit ≈ φ times the previous one. If we consider the Egyptian cubit as π/6 meters (which matches historical measurements), here's a possible insight:<p>Draw a circle with diameter 1 meter. Remove 1/6 of the perimeter (π/6), subtract the diameter (1), and you get ≈1.618 – essentially φ. This geometric construction lets you build an entire measurement system using just a stick and basic geometry. Once you have any two consecutive units, you can generate the entire sequence by addition (palm + span = foot) or subtraction (span – palm = thumb's breadth).<p>In the pre-metric French system, a span was exactly 20cm. When you scale 0.2 × φ² you get π/6 with 4-digit precision. But here's what's interesting: using our geometric approximation φ ≈ 5π/6 – 1, the equation 0.2 × φ² = π/6 works out *exactly*. The "approximation error" in φ perfectly cancels out due to φ² = φ + 1, making 0.2 × (5π/6 - 1 + 1) = π/6.<p>Here's another "coincidence": Multiple 17th-century scientists (Mersenne, Huygens, Wilkins) proposed defining a universal unit as the length of a pendulum with a half-period of 1 second. Tito Livio Burattini, inspired by his travels in Egypt, formalized this in his "Misura Universale" (1675), measuring this pendulum length at 0.9939 meters - essentially our modern meter.<p>The "revolutionary" meter system was really just formalizing measurement relationships that builders had been using for millennia. The French didn't invent it - they just gave ancient φ-based measurements a decimal makeover.
it could actualy be phrased the other way....
"the lack of a meter caused the french revolution"
ok, no, but it most definetly contributed to the revolution, as France was a maze of competing local measurement "standards" that caused a lot of problems and expense in business and trade, some of it wildly subjective, like an acre of land was not an area measurement, but was based on how much grain a given piece of land could grow.......and at one point before the revolution, there had begun a highly contentious attempt to straiten the whole mess out
10 days a week? Why. Because we have ten fingers, oc. 13 months was a year in the matriarchy, the lunar months... 12 was the monarchy and the church. We are back to 12 bc it is divisible for more numbers. But the metre was the great FR's legacy. It is under a dome, and you pay if you want a copy of fraternity. A inch does not exists. It's a just a fraction of the Paris' metre.
As an American, I finally relented and purchased a Metric measuring tape after the ordeal of trying to measure the dimensions of the rooms in my house. When it comes to interior decorating, trying to figure out how to evenly space items that are sized in feet, inches, and fractional inches is a nightmare. Imagine trying to space objects 2 feet 7½ inches long against a wall that is 13 feet 2 inches long. Now imagine this task with 80 centimeter long objects and a ~400 centimeter wall.<p>I am angry that IKEA's localization does not allow Americans to view dimensions in metric site-wide. You can still see dimensions in metric but those only appear on the pictures of some items. The webpage still converts all textual measurements to Imperial. You can't sort and search using metric values. IKEA designs everything in metric, using nice, even, whole numbers. Please let me see those. Seeing them converted to the nearest 32nd of an inch feels like vandalism.
Yeah, I know. That's why I make fun of it some times. Not because it is French; though an American I hope I am not a damned ungracious American, and though I believe we may fairly call the original debt squared after Normandy, I recognize and respect the generous Gallic heart from which it sprang.<p>But "the" metric system, so called, functions entirely on the happy coincidence of macroscopic distance being divisible at human discretion, while the similar and simultaneous effort at decimalizing time foundered on the rocks of how long it actually takes Earth to revolve upon its axis and to circle the sun. Both efforts originate in the same silly hamartiac human desire to prescribe a shape to which reality must conform, and thus may come in for about equal gentle contumely on that score. Especially since, in another example of its designers' foolishly misplaced priorities, metric offers no units at the human scale. They may have prefigured the brutalists in this way.