11 ms·

The metre originated in the French Revolution

126 points by Tomte 1y ago

elashri 1y ago
[flagged]
- skrebbel 1y ago
  > Easiest way to spot non-american author. Or the .com.au domain so you don't even need to read the article.
- throwanem 1y ago
  If you need to see mention of units of measure to distinguish an American from a Commonwealth dialect, I would suggest further study of either or both; for example, Americans never say "petrol."
skrebbel 1y ago
> (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.) That's actually impressively good accuracy for the time! Hats off to the astronomers.
- hilbert42 1y ago
  I was just about to post same quote but you beat me to it. I'd go further, I think their work was a remarkable feat for the late 1790s. That they achieved that accuracy given the primitive equipment of the day says much for their abilities and understanding. Also at the time France was in turmoil, numbers of its scientists were victims of the French Revolution—Antoine Lavoisier, probably the greatest chemist of his time—was beheaded by guillotine in 1794, so the political environment was anything but stable. Look back 225+ years ago: there was no electricity, no material science to speak of to make precision instrumentation—journal bearings on lathes, etc. couldn't be made with the accuracy of today, backlash would have been a constant worry. All instrumentation would have been crafted by hand. And the old French pre-metric system of units was an imperial system similar to the British (France even had an inch that was similar in length to British Imperial unit). All instrumentation up to that point would have relied on the less precise standards of that old system. Traveling was by horse and sailing ship, and so on. Surveying would have been difficult. There wasn't even the electric telegraph, only the crude optical Chappe telegraph, and even then it was only invented in the 1790s and wasn't fully implemented during the survey. They did a truly excellent job without any of today's high tech infrastructure but they made up for all these limitations by being brilliant. In today's modern world we often underestimate how inventive our forefathers were.
  - selkin 1y ago
    The pre-metric measurements in France weren’t imperial, but local: units had the same name, but different cities defined them differently. A livre[0] in one village was almost, but not quite, the livre used by the one only a couple toise[1] away. [0] about a modern pound, depending where you were. Toulouse’s livre was almost 1.3 modern pounds, for example. [1] about 13853/27000 meter.
    - hilbert42 1y ago
      You're right, I should have put 'imperial' in quotes as it's not the same as the British Imperial measurement. You'll note however I did distinguish the French system from the British one by referring to it in lowercase, that was intentional. The issue came up in a round about way on HN several weeks ago and I should have been more careful here because I wasn't precise enough in my comment then. As I inferred in that post 'imperial' nomenclature is used rather loosely to refer to measurement and coinage/currency as they're often closely linked (in the sense that the 'Crown' once regulated both). Pre-revolution French coinage used the same 1/12/20 number divisions as did the old English LSD and currencies in other parts of Europe, and that system is often referred to as 'imperial' coinage which likely goes back to Roman Imperial Coinage — but to confuse matters it was decimal. One can't cover the long historical lineage here except to mention the sign for the Roman [decimal] denarius is 'd' which is also used for the LSD penny, 12 of which make the shilling (£=240d). So for various reasons both 'old' physical measurement and 'old' coinage are often referred to as (I)imperial. To add to the confusion, modern currencies when converting from LSD/1/12/20 to metric and '1/12… measurement' are often done around the same time. Nomenclature overlaps. For example, I'm in Australia and the 1966 conversion from LSD to metrified coinage occurred shortly before the metrication of measurement. It was all lumped together as Imperial (note u/c) to Metric (that's how the public perceived it). The Government staged both changeovers close enough so that the reeducation of the citizenry wasn't forgotten by the time the measurement program started. For the record here's part of length in the old French measurement system: "Pied du Roi (foot) ≈ 32.48 cm (Slightly longer than an English foot, which is about 30.48 cm.) Pouce (inch) = 1/12 of a pied ≈ 2.707 cm Ligne = 1/12 of a pouce ≈ 2.256 mm Toise ≈ 1.949 metres (A toise is 6 pieds.) <...>" The other units can be found on the same site: https://interessia.com/medieval-french-measurements/ https://interessia.com/medieval-french-measurements/
throwanem 1y ago
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. 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.
- Zanfa 1y ago
  You mean like my feet aren’t a foot long, my thumb isn’t an inch? Ironically, my pinky is a centimeter thick and a meter is when I take a long step.
  - Joker_vD 1y ago
    The width of my palm (with my thumb, tightly pressed to it) at its widest is 10 centimeters, which is quite handy. Oh, and my "inch" is almost exactly 3 centimeters.
    - capitainenemo 1y ago
      There's a couple of convenience approximations I use to work with US Imperial.. 30cm is a "metric foot" (it's actually even closer to 1 light nanosecond which is kinda cool for thinking about distances at computer speeds) 250ml is a "metric cup"
      - throwanem 1y ago
        And now the famous triviality of order-of-magnitude and unit conversion goes entirely out the window...
az09mugen 1y ago
Another fun fact dating from French revolution is the 10 hour-day, each hour had 100 minutes and each minutes 100 seconds : https://historyfacts.com/world-history/fact/france-had-a-calendar-with-10-hour-days-during-the-revolution/ https://historyfacts.com/world-history/fact/france-had-a-cal...
- paulorlando 1y ago
  Fun fact... or not so fun? For 12 years of the revolutionary era, France did use decimal time. And the calendar and clocks were organized around a 10 day week and a 10 hour day. But those changes, coupled with the loss of Sunday worship, had other effects on the population. Here’s an assessment of what was really meant and then lost by the elimination of Sunday: “‘The elderly ladies took advantage of the long journey (to church) to exchange old stories with other old gossips … they met friends and relatives on the way, or when they reached the county town, whom they enjoyed seeing … there then followed a meal or perhaps a reciprocal invitation, which led to one relative or another….’ But if that was the way it was for the old ladies, what did Sunday mean to ‘young girls, whose blood throbbed with the sweetest desire of nature!’ We can well understand their impatience, ‘they waited for each other at the start of the road they shared,’ they danced. “Now, however, when the Tenth Day came around, ‘the men were left to the devices they always had:’ the old men went to the tavern, and they bargained. The young men drank and, deprived of their ‘lovely village girls’, they quarrelled. As for the women, they had nothing left to do in village. The mothers were miserable in their little hamlets, the daughters too, and out of this came their need to gather together in crowds. If the need for recreation is necessary because of moral forces… there is absolutely no doubt that village girls find it very hard to bear privations which are likely to prolong their unmarried state: ‘in all regions the pleasure of love is the greatest pleasure.'” – from The Revolution Against the Church, From Reason to the Supreme Being, by Michel Vovelle, pp 158-159.
  - thrance 1y ago
    I know the real goal of the republican calendar was to undermine the Church's power by making it so Sundays would fall at random days of the week, and also screw over the workers by leaving them with a worse weekend-to-week ratio. However, all I ever read about this part of the revolution seems to indicate that people just didn't comply and went to church anyway on Sundays, and also didn't work that day. On that account, I feel likr your quote is kind of partisan. People wouldn't have been left lost and aimlessly drinking on their tenth day because of a lack of God, because they never quit going to church!
_1 1y ago
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- deleted 1y ago
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nancyminusone 1y ago
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'. That last one is what I have the biggest problem with. When you are doing anything with derived units, 'kilo' suddenly disappears.
- kergonath 1y ago
  > base-10 numbering system Having decimal numbers, it’s the best solution. Otherwise you’re bound to make mistakes scaling things up or down. > a liter is not a cubic meter Well, it’s a dm^3, close enough ;) Conversion is trivial, 1 m^3 is 1000 l. A cubic metre is a bit large for everyday use, but it makes sense e.g. when measuring water consumption or larger volumes. The litre also had the advantage of being close to 2 pints, so it already made sense as a unit when it was introduced. Contrary to hours with 100s. > 'kilogram' is the base unit, not 'gram' Yeah, this one is perplexing. It’s an annoying inconsistency on an otherwise beautifully regular system.
  - GlobalFrog 1y ago
    I don't understand your issue between gram and kilo gram: gram is the base unit and the prefix kilo, meaning one thousand just says that 1 kg = 1000 grams. It is exactly the same as meters and kilometers: meters is the base unit and 1 km = 1000 meters.
    - tokai 1y ago
      I think they mean that the gram is defined as 1/1000 of a kilogram. With a kilogram having a definition based on physical constants.
      - jabl 1y ago
        The kilogram is no longer defined by a physical artifact, fwiw. Anyway, the point is the inconsistency in the system due to the kilogram being the base unit. So derived units are defined in terms of kilogram rather than gram. Say, the unit of force, Newton (N), is defined as kgm/s^2 and not gm/s^2). Or pressure, Pascal (Pa) which is N/m^2 which inherits N being defined in terms of the kilogram). And so on. Anyway, an annoying inconsistency maybe but doesn't really affect usage of the system once you get used to it.
nartho 1y ago
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 !
- selkin 1y ago
  “The Measure of All Things” by Ken Adler[0] is a good, extremely readable book about their adventure, which was indeed wild. [0] https://en.wikipedia.org/wiki/Special:BookSources/978-0-349-11507-8 https://en.wikipedia.org/wiki/Special:BookSources/978-0-349-...
  - frasermarlow 1y ago
    Yes, this is a brilliant book, and well worth reading. Another other one in the same vein is "Longitude" by Dava Sobel: https://www.amazon.com/Longitude-Genius-Greatest-Scientific-Problem/dp/080271529X https://www.amazon.com/Longitude-Genius-Greatest-Scientific-...
BitwiseFool 1y ago
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. 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.
- lostlogin 1y ago
  > I am angry that IKEA's localization does not allow Americans to view dimensions in metric I’m not American and laughed at this. Welcome to the other side. Also, here in New Zealand people seem to do everything in metric, except their height and the weight of their baby. Why?
  - deleted 1y ago
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  - remram 1y ago
    As a Frenchman living in the US, my favorite Imperial units are the hand (3 hands to a foot) and the poppyseed (4 poppyseeds to a barleycorn, the shoe-size unit; 3 barleycorns to an inch). 10cm and 2mm. People stop asking me to convert to Imperial pretty quick.
    - nancyminusone 1y ago
      The US doesn't and never has used the imperial system, as it did not participate in the unit reforms of 1824. 5 us gallons is about 4 imperial gallons.
bambax 1y ago
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. 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. The metric system is incredibly useful and practical (of course) but there's something rigid and unpleasant about it.
- IAmBroom 1y ago
  I know modern craftsmen* who lament the same. Being able to divide things in 2, 3, 4, 6, or 12 is mechanically more useful than 2/5/10 (the former being achievable by drafting tools more easily). *Yes, it should be craftspeople, but that doesn't exactly sound like the same thing, and anyway all of them happen to be men.
  - claudex 1y ago
    Nohting prevent you to use the metric system and use 60cm (for example) as a base unit for your construction. So you can easily divide it by 12 if you want.
  - rags2riches 1y ago
    Just one example I'm familiar with. Drywall typically comes in widths of 1200 mm and are mounted on studs 600 mm c/c.
- Svip 1y ago
  Nothing's stopping you from defining beautiful ratios and express the result in metric units, like ISO 216.[0] It feels like an odd complaint about the utility of the metric system, as if it is the only system; ratios aren't even units themselves! [0] https://en.wikipedia.org/wiki/ISO_216 https://en.wikipedia.org/wiki/ISO_216
toolslive 1y ago
Still, wouldn't base 12 be better than base 10 ?
- IAmBroom 1y ago
  Pretty much everyone born from -2,500 BCE to ~1800 CE would agree, and a significant of those born since.
- ahazred8ta 1y ago
  https://dozenal.org/ https://dozenal.org/ The Dozenal Society of America would agree with you.
- sham1 1y ago
  Number bases are arbitrary. Like, base 12 certainly has interesting properties since it is a highly composite number, but a lot of the convenient representations can be achieved by using actual fractions instead of insisting on radix points/commas. For example, 1/4 being 0.3 in base 12 can make certain computations easier (just as a 1/3 being 0.4_12 would), but again, what's wrong with 1/4 and 1/3 respectively. Of course, things like duodecimal and base-6 are interesting to use, but at this point the convention is base-10 and it probably won't change for a while. It's kinda like the \pi Vs \tau debate, where even with all the elegance and easier pedagogy brought by the use of \tau as the fundamental circle constant, the existing convention does matter, and probably matters a lot more in general than the better alternative. Of course, this also applied to the SI units. It literally took a major historical revolution for these units to be a) defined and b) getting used over the old units.
  - timewizard 1y ago
    > Number bases are arbitrary. You could do it that way if you didn't care at all for how people actually use the system or what they would prefer; however, it's just your decision that's arbitrary, not the actual choice of "best base for worldwide everyday use." > 1/4 being 0.3 in base 12 And 5/6ths is 0.A in hexadecimal base 12. The choice of a base should imply a choice of alphabet. For something like base 12 you may actually want to rediscover or invent new numeral characters. > but at this point the convention is base-10 Except for time. Which appears constantly in physical units. > b) getting used over the old units. Even then. No one will tell you the sun is "93 Gm" from Earth. It's always 93 million km. They haven't exactly gotten into the new system just yet. They've just swapped base units.
metalman 1y ago
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
Xmd5a 1y ago
The meter wasn't invented during the French Revolution, it evolved from ancient measurement systems based on the golden ratio. 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: 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). 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. 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. 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.
- cooljoseph 1y ago
  It is possible to construct φ exactly with a straight-edge and compass. Would the approximation of 5π/6 - 1 be used because it's easier to calculate quickly?
  - Xmd5a 1y ago
    Yes φ is a constructible number and more generally an algebraic number, solution of the polynomial equation x^2 = x + 1. However π is not, and so is my approximation of φ as 5π/6 - 1. Here non-constructibility (in the mathematical sense) translates to the fact there is no method to "straighten" an arc into a segment using a compass and a ruler. But bear with me because the 5π/6 - 1 approximation of phi has more to say. First, the "conspiracy theory" that the meter is linked to Earth's dimensions and harmonizes with ancient measurement units through a shared reference actually predates the meter's definition. This idea was a thread of interest among the scientists who developed a universal measurement system – one that could be derived anywhere on the planet. >One can well sense that it can only be through comparisons of measurements made in ancient times & in our days on monuments still existing, that I can determine to how many of our toises the Geometers of antiquity would have evaluated a degree of Meridian. Now I find, 1st. that the side of the base of the great pyramid of Egypt taken five hundred times; 2nd. that the cubit of the Nilometer taken two hundred thousand times; 3rd. that a stadium existing & measured at Laodicea in Asia Minor, by Mr. Smith, & taken five hundred times; I find, I say, that these three products are each of the same value, & that each in particular is precisely the same measure of a degree [of a Meridian], which has been determined by our modern Geometers. Alexis-Jean-Pierre Paucton, Metrology, or Treatise on measures, weights and currencies, of the ancients and the moderns, 1780 more context: https://anonpaste.pw/v/71abb0f8-5a03-4cb5-879a-d4f44ad6d57c#hMnr9C9KpWknQKAYNV6WTkNzZaQTZ177cf-q913BkRM https://anonpaste.pw/v/71abb0f8-5a03-4cb5-879a-d4f44ad6d57c#... original: https://gallica.bnf.fr/ark:/12148/bpt6k55491755/f126.item https://gallica.bnf.fr/ark:/12148/bpt6k55491755/f126.item >Newton was trying to uncover the unit of measurement used by those constructing the pyramids. He thought it was likely that the ancient Egyptians had been able to measure the Earth and that, by unlocking the cubit of the Great Pyramid, he too would be able to measure the circumference of the Earth. https://www.theguardian.com/science/2020/dec/06/revealed-isaac-newtons-attempts-to-unlock-secret-code-of-pyramids https://www.theguardian.com/science/2020/dec/06/revealed-isa... Having said that(-1 downvotes!), let's recap: This is how we can construct a royal cubit from a circle of diameter = 1m: https://imgur.com/a/HmnfDKR https://imgur.com/a/HmnfDKR φ = 2cos(π/5) lead us to this construction around a pentagon from which we can derive the "pige" or "quine" of cathedral builders (for now consider this is historically true) https://fr.wikipedia.org/wiki/Pige_(mesure) https://fr.wikipedia.org/wiki/Pige_(mesure) https://imgur.com/a/ZqprfAd https://imgur.com/a/ZqprfAd What I mentioned earlier was that using a circle-based construction(diameter = 1m), one can derive a non-constructible approximation of φ, namely φ̃ = 5π/6 – 1, with the remarkable property that 0.2 × φ̃² = π/6, thanks to φ² = φ + 1. But what’s truly elegant is that this process has a symmetric counterpart, where we approximate π using φ. This time, we begin with a constructible triangle, sometimes called the triangle of the builders (1, 2, √5), whose perimeter is: t = (1 + 2 + √5)/10 This value is fully constructible with compass and straightedge, and numerically it approximates π/6 to four digits. If we treat this `t` as a stand-in for π/6 in the previous formula: φ = 5t – 1 we recover the *exact golden ratio*: φ = (5 × (3 + √5)/10) – 1 = (1 + √5)/2 And then, going full circle: 0.2 × φ² = t again In both directions, 0.2 (i.e., 1/5) emerges as the key scaling factor, bridging the decimal system, φ, and π through geometry. It ties together: - the constructible (t from the triangle), - the transcendental (π/6 from the circle), and - the algebraic (φ² = φ + 1) ^this is a new result I just found. For the historically conservative, arguments can be made that these considerations are pseudo-historical, that the "quine of cathedral builders" is an unsubstantiated myth. See the wikipedia link above for the "pige" or this recent article: https://classiques-garnier.com/aedificare-2021-2-revue-internationale-d-histoire-de-la-construction-n-10-varia-la-corde-a-treize-noeuds-et-la-quine-des-batisseurs.html https://classiques-garnier.com/aedificare-2021-2-revue-inter... this one too: http://compagnonsdudevoir.fr/?p=790 http://compagnonsdudevoir.fr/?p=790 >This greatly saddens those who have built an entire "operative" narrative around this kind of knowledge supposedly passed down in secret among the compagnons of the Tour de France for centuries… and have made it their pedestal. The question of how "tradition" is constructed among the compagnons (and incidentally among the Freemasons) remains a taboo that absolutely needs to be broken — and not just for the sake of advancing historical knowledge. Also this blog post traces the confabulation of the quine to Le Corbusier's Modulor system based on the golden ratio: https://blogruz.blogspot.com/2007/12/en-qui-quine.html https://blogruz.blogspot.com/2007/12/en-qui-quine.html >Le Corbusier considered various sets of proportions, notably using a human height of 1.75 meters, before settling in 1947 on a single set based on a height of 1.83 meters. He chose this because the associated Modulor measurement of 226 cm corresponds to within less than a millimeter of 89 inches — 89 being a number in the Fibonacci sequence that provides some of the best approximations of the golden ratio. >This system was intended to unite all nations around a universal standard, effectively casting aside the metric system, if not the decimal system entirely. We know how that turned out: the Modulor was essentially used for only one major creation — albeit a significant one — the Cité Radieuse in Marseille, completed in 1952, where all dimensions, down to the built-in furniture, are derived from the Modulor. Makes you think... The fact we don't have documents isn't surprising given that the campagnons (or later freemasons) communicated practical (then mystical) knowledge esoterically for political reasons (See https://fr.wikipedia.org/wiki/Compagnonnage https://fr.wikipedia.org/wiki/Compagnonnage). Nonetheless, the same motivations and the same quest for harmony (in the obsessive, symbolic sense) can be observed in Le Corbusier. As if the situation follows a geometric progression: in this sense, the "ancients" were as puzzled as we are by unexpected harmonies and actively sought them, and if you look at the historical sequence that lead to the definition of the meter, this is what you find. Compare the length of a greek foot with a roman foot: 30.87cm vs 29.62cm. The ratio matches 24/25 with 3 nines of precision. 24•25•7 forms a pythagorean triangle. As if the definition of some measurement units were retrofitted to facilitate conversion. If this kind of behavior leads to the formation of a strange graph of quasi-conversions or numerical coincidences, then maybe we could explain the emergence of patterns such as the 5π/6 - 1 approximation of φ without needing to argue for (or against) someone's intention behind what appears as a design choice. Alternatively the measures of the tools or geometric constructs that drive these conversions are idealized/approximated with a ratio, hence the delusion of the conspiracy theorists. But as I said, "ancients" had the same attitude, in particular with irrational numbers they wished to express as a ratio. Imagine the kind of problem the pseudo-phi <-> pseudo-π/6 complex I desribed above posed to people who where attempting to construct a straight line of length pi using only a compass and a straight-edge and establishing mathematics more rigorously. That's quite a nasty trap. Surely they found themselves in a mindstate that must not be that different from ours. Put in other words, the situation is hyperstionnal, and if we want to understand what is happening (whether this is an illusion or not) I think we should try to tackle this from a cognitive angle and model surprise explicitly. Some more links: https://www.messagedelanuitdestemps.org/les-principales-unites-de-mesures-anciennes-et-leurs-secrets/ https://www.messagedelanuitdestemps.org/les-principales-unit... https://martouf.ch/2021/03/le-metre-une-matrice-universelle-a-lorigine-mysterieuse/ https://martouf.ch/2021/03/le-metre-une-matrice-universelle-...
dudeinjapan 1y ago
So did the guillotine, but that doesn't mean everyone should go around using them.
rippeltippel 1y ago
> 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). 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.
- grey413 1y ago
  There's a consistent effort to make all the SI metric units based off of discreet measurements of physical constants. The speed of light is a constant, and the SI second is "defined by taking the fixed numerical value of the caesium frequency ΔνCs, the unperturbed ground-state hyperfine transition frequency of the caesium-133 atom, to be 9,192,631,770 when expressed in the unit Hz, which is equal to s^–1"
- mitthrowaway2 1y ago
  It's a way of expressing the backwards compatibility of the new definition, set to match the old one so that everybody's distance measures remain usable when the definition changes.
willsoon 1y ago
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.
n1b0m 1y ago
“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.” What unit did they use to measure the length of the platinum bar?
- atvcatole 1y ago
  I believe they used Parisian variants of the french units. They measured the distance between the Mediterranean Sea and the North Sea through Paris with platinum rulers measuring 2 Toise de Paris. The toise was different in different parts of France, so it was specifically the Paris one they used, and the goal was to get rid of local variants of the same units with vague definitions like toise, point, line, inch, feet, mil(e) etc. Once they had the distance in Toise de Paris and did some math they could define the circumference of the earth and define the meter at 1/40 000 000 of that. That length was 443.44 Lignes de Paris where a ligne is 1/864 toise.
laacz 1y ago
This is weird. I always thought that not astronomers, but two blokes named Delambre and Méchain were responsible for this [1]. > The arc measurement of Delambre and Méchain was a geodetic survey carried out by Jean-Baptiste Delambre and Pierre Méchain in 1792–1798 to measure an arc section of the Paris meridian between Dunkirk and Barcelona. This arc measurement served as the basis for the original definition of the metre. [1] https://en.wikipedia.org/wiki/Arc_measurement_of_Delambre_and_M%C3%A9chain https://en.wikipedia.org/wiki/Arc_measurement_of_Delambre_an...

126 points by Tomte 1y ago

elashri 1y ago

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skrebbel 1y ago
> Easiest way to spot non-american author. Or the .com.au domain so you don't even need to read the article.
throwanem 1y ago
If you need to see mention of units of measure to distinguish an American from a Commonwealth dialect, I would suggest further study of either or both; for example, Americans never say "petrol."

skrebbel 1y ago

> (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.) That's actually impressively good accuracy for the time! Hats off to the astronomers.

hilbert42 1y ago
I was just about to post same quote but you beat me to it. I'd go further, I think their work was a remarkable feat for the late 1790s. That they achieved that accuracy given the primitive equipment of the day says much for their abilities and understanding. Also at the time France was in turmoil, numbers of its scientists were victims of the French Revolution—Antoine Lavoisier, probably the greatest chemist of his time—was beheaded by guillotine in 1794, so the political environment was anything but stable. Look back 225+ years ago: there was no electricity, no material science to speak of to make precision instrumentation—journal bearings on lathes, etc. couldn't be made with the accuracy of today, backlash would have been a constant worry. All instrumentation would have been crafted by hand. And the old French pre-metric system of units was an imperial system similar to the British (France even had an inch that was similar in length to British Imperial unit). All instrumentation up to that point would have relied on the less precise standards of that old system. Traveling was by horse and sailing ship, and so on. Surveying would have been difficult. There wasn't even the electric telegraph, only the crude optical Chappe telegraph, and even then it was only invented in the 1790s and wasn't fully implemented during the survey. They did a truly excellent job without any of today's high tech infrastructure but they made up for all these limitations by being brilliant. In today's modern world we often underestimate how inventive our forefathers were.
- selkin 1y ago
  The pre-metric measurements in France weren’t imperial, but local: units had the same name, but different cities defined them differently. A livre[0] in one village was almost, but not quite, the livre used by the one only a couple toise[1] away. [0] about a modern pound, depending where you were. Toulouse’s livre was almost 1.3 modern pounds, for example. [1] about 13853/27000 meter.
  - hilbert42 1y ago
    You're right, I should have put 'imperial' in quotes as it's not the same as the British Imperial measurement. You'll note however I did distinguish the French system from the British one by referring to it in lowercase, that was intentional. The issue came up in a round about way on HN several weeks ago and I should have been more careful here because I wasn't precise enough in my comment then. As I inferred in that post 'imperial' nomenclature is used rather loosely to refer to measurement and coinage/currency as they're often closely linked (in the sense that the 'Crown' once regulated both). Pre-revolution French coinage used the same 1/12/20 number divisions as did the old English LSD and currencies in other parts of Europe, and that system is often referred to as 'imperial' coinage which likely goes back to Roman Imperial Coinage — but to confuse matters it was decimal. One can't cover the long historical lineage here except to mention the sign for the Roman [decimal] denarius is 'd' which is also used for the LSD penny, 12 of which make the shilling (£=240d). So for various reasons both 'old' physical measurement and 'old' coinage are often referred to as (I)imperial. To add to the confusion, modern currencies when converting from LSD/1/12/20 to metric and '1/12… measurement' are often done around the same time. Nomenclature overlaps. For example, I'm in Australia and the 1966 conversion from LSD to metrified coinage occurred shortly before the metrication of measurement. It was all lumped together as Imperial (note u/c) to Metric (that's how the public perceived it). The Government staged both changeovers close enough so that the reeducation of the citizenry wasn't forgotten by the time the measurement program started. For the record here's part of length in the old French measurement system: "Pied du Roi (foot) ≈ 32.48 cm (Slightly longer than an English foot, which is about 30.48 cm.) Pouce (inch) = 1/12 of a pied ≈ 2.707 cm Ligne = 1/12 of a pouce ≈ 2.256 mm Toise ≈ 1.949 metres (A toise is 6 pieds.) <...>" The other units can be found on the same site: https://interessia.com/medieval-french-measurements/ https://interessia.com/medieval-french-measurements/

throwanem 1y ago

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. 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.

Zanfa 1y ago
You mean like my feet aren’t a foot long, my thumb isn’t an inch? Ironically, my pinky is a centimeter thick and a meter is when I take a long step.
- Joker_vD 1y ago
  The width of my palm (with my thumb, tightly pressed to it) at its widest is 10 centimeters, which is quite handy. Oh, and my "inch" is almost exactly 3 centimeters.
  - capitainenemo 1y ago
    There's a couple of convenience approximations I use to work with US Imperial.. 30cm is a "metric foot" (it's actually even closer to 1 light nanosecond which is kinda cool for thinking about distances at computer speeds) 250ml is a "metric cup"
    - throwanem 1y ago
      And now the famous triviality of order-of-magnitude and unit conversion goes entirely out the window...

az09mugen 1y ago

Another fun fact dating from French revolution is the 10 hour-day, each hour had 100 minutes and each minutes 100 seconds : https://historyfacts.com/world-history/fact/france-had-a-calendar-with-10-hour-days-during-the-revolution/ https://historyfacts.com/world-history/fact/france-had-a-cal...

paulorlando 1y ago
Fun fact... or not so fun? For 12 years of the revolutionary era, France did use decimal time. And the calendar and clocks were organized around a 10 day week and a 10 hour day. But those changes, coupled with the loss of Sunday worship, had other effects on the population. Here’s an assessment of what was really meant and then lost by the elimination of Sunday: “‘The elderly ladies took advantage of the long journey (to church) to exchange old stories with other old gossips … they met friends and relatives on the way, or when they reached the county town, whom they enjoyed seeing … there then followed a meal or perhaps a reciprocal invitation, which led to one relative or another….’ But if that was the way it was for the old ladies, what did Sunday mean to ‘young girls, whose blood throbbed with the sweetest desire of nature!’ We can well understand their impatience, ‘they waited for each other at the start of the road they shared,’ they danced. “Now, however, when the Tenth Day came around, ‘the men were left to the devices they always had:’ the old men went to the tavern, and they bargained. The young men drank and, deprived of their ‘lovely village girls’, they quarrelled. As for the women, they had nothing left to do in village. The mothers were miserable in their little hamlets, the daughters too, and out of this came their need to gather together in crowds. If the need for recreation is necessary because of moral forces… there is absolutely no doubt that village girls find it very hard to bear privations which are likely to prolong their unmarried state: ‘in all regions the pleasure of love is the greatest pleasure.'” – from The Revolution Against the Church, From Reason to the Supreme Being, by Michel Vovelle, pp 158-159.
- thrance 1y ago
  I know the real goal of the republican calendar was to undermine the Church's power by making it so Sundays would fall at random days of the week, and also screw over the workers by leaving them with a worse weekend-to-week ratio. However, all I ever read about this part of the revolution seems to indicate that people just didn't comply and went to church anyway on Sundays, and also didn't work that day. On that account, I feel likr your quote is kind of partisan. People wouldn't have been left lost and aimlessly drinking on their tenth day because of a lack of God, because they never quit going to church!

_1 1y ago

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nancyminusone 1y ago

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'. That last one is what I have the biggest problem with. When you are doing anything with derived units, 'kilo' suddenly disappears.

kergonath 1y ago
> base-10 numbering system Having decimal numbers, it’s the best solution. Otherwise you’re bound to make mistakes scaling things up or down. > a liter is not a cubic meter Well, it’s a dm^3, close enough ;) Conversion is trivial, 1 m^3 is 1000 l. A cubic metre is a bit large for everyday use, but it makes sense e.g. when measuring water consumption or larger volumes. The litre also had the advantage of being close to 2 pints, so it already made sense as a unit when it was introduced. Contrary to hours with 100s. > 'kilogram' is the base unit, not 'gram' Yeah, this one is perplexing. It’s an annoying inconsistency on an otherwise beautifully regular system.
- GlobalFrog 1y ago
  I don't understand your issue between gram and kilo gram: gram is the base unit and the prefix kilo, meaning one thousand just says that 1 kg = 1000 grams. It is exactly the same as meters and kilometers: meters is the base unit and 1 km = 1000 meters.
  - tokai 1y ago
    I think they mean that the gram is defined as 1/1000 of a kilogram. With a kilogram having a definition based on physical constants.
    - jabl 1y ago
      The kilogram is no longer defined by a physical artifact, fwiw. Anyway, the point is the inconsistency in the system due to the kilogram being the base unit. So derived units are defined in terms of kilogram rather than gram. Say, the unit of force, Newton (N), is defined as kgm/s^2 and not gm/s^2). Or pressure, Pascal (Pa) which is N/m^2 which inherits N being defined in terms of the kilogram). And so on. Anyway, an annoying inconsistency maybe but doesn't really affect usage of the system once you get used to it.

nartho 1y ago

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 !

selkin 1y ago
“The Measure of All Things” by Ken Adler[0] is a good, extremely readable book about their adventure, which was indeed wild. [0] https://en.wikipedia.org/wiki/Special:BookSources/978-0-349-11507-8 https://en.wikipedia.org/wiki/Special:BookSources/978-0-349-...
- frasermarlow 1y ago
  Yes, this is a brilliant book, and well worth reading. Another other one in the same vein is "Longitude" by Dava Sobel: https://www.amazon.com/Longitude-Genius-Greatest-Scientific-Problem/dp/080271529X https://www.amazon.com/Longitude-Genius-Greatest-Scientific-...

BitwiseFool 1y ago

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. 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.

lostlogin 1y ago
> I am angry that IKEA's localization does not allow Americans to view dimensions in metric I’m not American and laughed at this. Welcome to the other side. Also, here in New Zealand people seem to do everything in metric, except their height and the weight of their baby. Why?
- deleted 1y ago
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- remram 1y ago
  As a Frenchman living in the US, my favorite Imperial units are the hand (3 hands to a foot) and the poppyseed (4 poppyseeds to a barleycorn, the shoe-size unit; 3 barleycorns to an inch). 10cm and 2mm. People stop asking me to convert to Imperial pretty quick.
  - nancyminusone 1y ago
    The US doesn't and never has used the imperial system, as it did not participate in the unit reforms of 1824. 5 us gallons is about 4 imperial gallons.

bambax 1y ago

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. 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. The metric system is incredibly useful and practical (of course) but there's something rigid and unpleasant about it.

IAmBroom 1y ago
I know modern craftsmen* who lament the same. Being able to divide things in 2, 3, 4, 6, or 12 is mechanically more useful than 2/5/10 (the former being achievable by drafting tools more easily). *Yes, it should be craftspeople, but that doesn't exactly sound like the same thing, and anyway all of them happen to be men.
- claudex 1y ago
  Nohting prevent you to use the metric system and use 60cm (for example) as a base unit for your construction. So you can easily divide it by 12 if you want.
- rags2riches 1y ago
  Just one example I'm familiar with. Drywall typically comes in widths of 1200 mm and are mounted on studs 600 mm c/c.
Svip 1y ago
Nothing's stopping you from defining beautiful ratios and express the result in metric units, like ISO 216.[0] It feels like an odd complaint about the utility of the metric system, as if it is the only system; ratios aren't even units themselves! [0] https://en.wikipedia.org/wiki/ISO_216 https://en.wikipedia.org/wiki/ISO_216

toolslive 1y ago

Still, wouldn't base 12 be better than base 10 ?

IAmBroom 1y ago
Pretty much everyone born from -2,500 BCE to ~1800 CE would agree, and a significant of those born since.
ahazred8ta 1y ago
https://dozenal.org/ https://dozenal.org/ The Dozenal Society of America would agree with you.
sham1 1y ago
Number bases are arbitrary. Like, base 12 certainly has interesting properties since it is a highly composite number, but a lot of the convenient representations can be achieved by using actual fractions instead of insisting on radix points/commas. For example, 1/4 being 0.3 in base 12 can make certain computations easier (just as a 1/3 being 0.4_12 would), but again, what's wrong with 1/4 and 1/3 respectively. Of course, things like duodecimal and base-6 are interesting to use, but at this point the convention is base-10 and it probably won't change for a while. It's kinda like the \pi Vs \tau debate, where even with all the elegance and easier pedagogy brought by the use of \tau as the fundamental circle constant, the existing convention does matter, and probably matters a lot more in general than the better alternative. Of course, this also applied to the SI units. It literally took a major historical revolution for these units to be a) defined and b) getting used over the old units.
- timewizard 1y ago
  > Number bases are arbitrary. You could do it that way if you didn't care at all for how people actually use the system or what they would prefer; however, it's just your decision that's arbitrary, not the actual choice of "best base for worldwide everyday use." > 1/4 being 0.3 in base 12 And 5/6ths is 0.A in hexadecimal base 12. The choice of a base should imply a choice of alphabet. For something like base 12 you may actually want to rediscover or invent new numeral characters. > but at this point the convention is base-10 Except for time. Which appears constantly in physical units. > b) getting used over the old units. Even then. No one will tell you the sun is "93 Gm" from Earth. It's always 93 million km. They haven't exactly gotten into the new system just yet. They've just swapped base units.

metalman 1y ago

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

Xmd5a 1y ago

The meter wasn't invented during the French Revolution, it evolved from ancient measurement systems based on the golden ratio. 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: 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). 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. 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. 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.

cooljoseph 1y ago
It is possible to construct φ exactly with a straight-edge and compass. Would the approximation of 5π/6 - 1 be used because it's easier to calculate quickly?
- Xmd5a 1y ago
  Yes φ is a constructible number and more generally an algebraic number, solution of the polynomial equation x^2 = x + 1. However π is not, and so is my approximation of φ as 5π/6 - 1. Here non-constructibility (in the mathematical sense) translates to the fact there is no method to "straighten" an arc into a segment using a compass and a ruler. But bear with me because the 5π/6 - 1 approximation of phi has more to say. First, the "conspiracy theory" that the meter is linked to Earth's dimensions and harmonizes with ancient measurement units through a shared reference actually predates the meter's definition. This idea was a thread of interest among the scientists who developed a universal measurement system – one that could be derived anywhere on the planet. >One can well sense that it can only be through comparisons of measurements made in ancient times & in our days on monuments still existing, that I can determine to how many of our toises the Geometers of antiquity would have evaluated a degree of Meridian. Now I find, 1st. that the side of the base of the great pyramid of Egypt taken five hundred times; 2nd. that the cubit of the Nilometer taken two hundred thousand times; 3rd. that a stadium existing & measured at Laodicea in Asia Minor, by Mr. Smith, & taken five hundred times; I find, I say, that these three products are each of the same value, & that each in particular is precisely the same measure of a degree [of a Meridian], which has been determined by our modern Geometers. Alexis-Jean-Pierre Paucton, Metrology, or Treatise on measures, weights and currencies, of the ancients and the moderns, 1780 more context: https://anonpaste.pw/v/71abb0f8-5a03-4cb5-879a-d4f44ad6d57c#hMnr9C9KpWknQKAYNV6WTkNzZaQTZ177cf-q913BkRM https://anonpaste.pw/v/71abb0f8-5a03-4cb5-879a-d4f44ad6d57c#... original: https://gallica.bnf.fr/ark:/12148/bpt6k55491755/f126.item https://gallica.bnf.fr/ark:/12148/bpt6k55491755/f126.item >Newton was trying to uncover the unit of measurement used by those constructing the pyramids. He thought it was likely that the ancient Egyptians had been able to measure the Earth and that, by unlocking the cubit of the Great Pyramid, he too would be able to measure the circumference of the Earth. https://www.theguardian.com/science/2020/dec/06/revealed-isaac-newtons-attempts-to-unlock-secret-code-of-pyramids https://www.theguardian.com/science/2020/dec/06/revealed-isa... Having said that(-1 downvotes!), let's recap: This is how we can construct a royal cubit from a circle of diameter = 1m: https://imgur.com/a/HmnfDKR https://imgur.com/a/HmnfDKR φ = 2cos(π/5) lead us to this construction around a pentagon from which we can derive the "pige" or "quine" of cathedral builders (for now consider this is historically true) https://fr.wikipedia.org/wiki/Pige_(mesure) https://fr.wikipedia.org/wiki/Pige_(mesure) https://imgur.com/a/ZqprfAd https://imgur.com/a/ZqprfAd What I mentioned earlier was that using a circle-based construction(diameter = 1m), one can derive a non-constructible approximation of φ, namely φ̃ = 5π/6 – 1, with the remarkable property that 0.2 × φ̃² = π/6, thanks to φ² = φ + 1. But what’s truly elegant is that this process has a symmetric counterpart, where we approximate π using φ. This time, we begin with a constructible triangle, sometimes called the triangle of the builders (1, 2, √5), whose perimeter is: t = (1 + 2 + √5)/10 This value is fully constructible with compass and straightedge, and numerically it approximates π/6 to four digits. If we treat this `t` as a stand-in for π/6 in the previous formula: φ = 5t – 1 we recover the *exact golden ratio*: φ = (5 × (3 + √5)/10) – 1 = (1 + √5)/2 And then, going full circle: 0.2 × φ² = t again In both directions, 0.2 (i.e., 1/5) emerges as the key scaling factor, bridging the decimal system, φ, and π through geometry. It ties together: - the constructible (t from the triangle), - the transcendental (π/6 from the circle), and - the algebraic (φ² = φ + 1) ^this is a new result I just found. For the historically conservative, arguments can be made that these considerations are pseudo-historical, that the "quine of cathedral builders" is an unsubstantiated myth. See the wikipedia link above for the "pige" or this recent article: https://classiques-garnier.com/aedificare-2021-2-revue-internationale-d-histoire-de-la-construction-n-10-varia-la-corde-a-treize-noeuds-et-la-quine-des-batisseurs.html https://classiques-garnier.com/aedificare-2021-2-revue-inter... this one too: http://compagnonsdudevoir.fr/?p=790 http://compagnonsdudevoir.fr/?p=790 >This greatly saddens those who have built an entire "operative" narrative around this kind of knowledge supposedly passed down in secret among the compagnons of the Tour de France for centuries… and have made it their pedestal. The question of how "tradition" is constructed among the compagnons (and incidentally among the Freemasons) remains a taboo that absolutely needs to be broken — and not just for the sake of advancing historical knowledge. Also this blog post traces the confabulation of the quine to Le Corbusier's Modulor system based on the golden ratio: https://blogruz.blogspot.com/2007/12/en-qui-quine.html https://blogruz.blogspot.com/2007/12/en-qui-quine.html >Le Corbusier considered various sets of proportions, notably using a human height of 1.75 meters, before settling in 1947 on a single set based on a height of 1.83 meters. He chose this because the associated Modulor measurement of 226 cm corresponds to within less than a millimeter of 89 inches — 89 being a number in the Fibonacci sequence that provides some of the best approximations of the golden ratio. >This system was intended to unite all nations around a universal standard, effectively casting aside the metric system, if not the decimal system entirely. We know how that turned out: the Modulor was essentially used for only one major creation — albeit a significant one — the Cité Radieuse in Marseille, completed in 1952, where all dimensions, down to the built-in furniture, are derived from the Modulor. Makes you think... The fact we don't have documents isn't surprising given that the campagnons (or later freemasons) communicated practical (then mystical) knowledge esoterically for political reasons (See https://fr.wikipedia.org/wiki/Compagnonnage https://fr.wikipedia.org/wiki/Compagnonnage). Nonetheless, the same motivations and the same quest for harmony (in the obsessive, symbolic sense) can be observed in Le Corbusier. As if the situation follows a geometric progression: in this sense, the "ancients" were as puzzled as we are by unexpected harmonies and actively sought them, and if you look at the historical sequence that lead to the definition of the meter, this is what you find. Compare the length of a greek foot with a roman foot: 30.87cm vs 29.62cm. The ratio matches 24/25 with 3 nines of precision. 24•25•7 forms a pythagorean triangle. As if the definition of some measurement units were retrofitted to facilitate conversion. If this kind of behavior leads to the formation of a strange graph of quasi-conversions or numerical coincidences, then maybe we could explain the emergence of patterns such as the 5π/6 - 1 approximation of φ without needing to argue for (or against) someone's intention behind what appears as a design choice. Alternatively the measures of the tools or geometric constructs that drive these conversions are idealized/approximated with a ratio, hence the delusion of the conspiracy theorists. But as I said, "ancients" had the same attitude, in particular with irrational numbers they wished to express as a ratio. Imagine the kind of problem the pseudo-phi <-> pseudo-π/6 complex I desribed above posed to people who where attempting to construct a straight line of length pi using only a compass and a straight-edge and establishing mathematics more rigorously. That's quite a nasty trap. Surely they found themselves in a mindstate that must not be that different from ours. Put in other words, the situation is hyperstionnal, and if we want to understand what is happening (whether this is an illusion or not) I think we should try to tackle this from a cognitive angle and model surprise explicitly. Some more links: https://www.messagedelanuitdestemps.org/les-principales-unites-de-mesures-anciennes-et-leurs-secrets/ https://www.messagedelanuitdestemps.org/les-principales-unit... https://martouf.ch/2021/03/le-metre-une-matrice-universelle-a-lorigine-mysterieuse/ https://martouf.ch/2021/03/le-metre-une-matrice-universelle-...

dudeinjapan 1y ago

So did the guillotine, but that doesn't mean everyone should go around using them.

rippeltippel 1y ago

> 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). 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.

grey413 1y ago
There's a consistent effort to make all the SI metric units based off of discreet measurements of physical constants. The speed of light is a constant, and the SI second is "defined by taking the fixed numerical value of the caesium frequency ΔνCs, the unperturbed ground-state hyperfine transition frequency of the caesium-133 atom, to be 9,192,631,770 when expressed in the unit Hz, which is equal to s^–1"
mitthrowaway2 1y ago
It's a way of expressing the backwards compatibility of the new definition, set to match the old one so that everybody's distance measures remain usable when the definition changes.

willsoon 1y ago

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.

n1b0m 1y ago

“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.” What unit did they use to measure the length of the platinum bar?

atvcatole 1y ago
I believe they used Parisian variants of the french units. They measured the distance between the Mediterranean Sea and the North Sea through Paris with platinum rulers measuring 2 Toise de Paris. The toise was different in different parts of France, so it was specifically the Paris one they used, and the goal was to get rid of local variants of the same units with vague definitions like toise, point, line, inch, feet, mil(e) etc. Once they had the distance in Toise de Paris and did some math they could define the circumference of the earth and define the meter at 1/40 000 000 of that. That length was 443.44 Lignes de Paris where a ligne is 1/864 toise.

laacz 1y ago

This is weird. I always thought that not astronomers, but two blokes named Delambre and Méchain were responsible for this [1]. > The arc measurement of Delambre and Méchain was a geodetic survey carried out by Jean-Baptiste Delambre and Pierre Méchain in 1792–1798 to measure an arc section of the Paris meridian between Dunkirk and Barcelona. This arc measurement served as the basis for the original definition of the metre. [1] https://en.wikipedia.org/wiki/Arc_measurement_of_Delambre_and_M%C3%A9chain https://en.wikipedia.org/wiki/Arc_measurement_of_Delambre_an...