Hacker News Reader

Comment by vondur | Hacker News Reader

One of the good things that came out of the French Revolution was the metric system. Not so much with the revolutionary calendar.

View on HN

Well, unfortunately it just didn't catch on. In many ways it made much more sense than the calendar system we still use today.

It also has the added benefit of celebrating an event most modern people probably can relate to and are in favour of (the bloody struggle and oppressive regime that came afterwards admittedly not so much though ...) instead of the arbitrarily fixed year of birth of a religious figure many people are more or less indifferent about.

On a side note, PHP interestingly has had native support for the Revolutionary Calendar for a long time: http://php.net/manual/en/function.jdtofrench.php

It is a cruel fact that 365 is so poorly dividable (prime factors are 5 and 73). 7413 is pretty much the closest we can get. I imagine having one extra day in the calendar is easier to swallow for most organizations (and people) than five extra days. And of course 7 day week has the advantage of familarity. 10 day weeks sound somewhat heavy, I suppose most people would have 7 day workweek and 3 day weekend. While 3 day weekend sounds nice, you also get about 30% fewer weekends. The 7 days of work would be fairly radical extension, can't imagine that being popular among anyone.

I would not mind working four days, having one free day, working another three days, and then having a weekend of two days, for example. Indeed, familiarity is the key here, but I am sure we could get used to a week of 10 (or any other number of) days.

That could be also described as a five-day week with alternating 4/1 - 3/2 work/free division. But of course such ideas don't fit into the french revolutions obsession with decimal system.

I think the best option would be to use 13 months. You get 13 months with 4 weeks and an extra day (365%13=1). This extra day could be set aside as a special case. I would use it for the first day of the year.

Yeah, 7 * 4 * 13 + 1 is kinda nice. But it does not really fit in any way into decimal system. If we accept the 5ish extra days, then 360 gives us lots of different options on how to do the divisions. For example 10 months with 6 weeks, 6 days each, has its own sort of elegance to it. And it has that tiny bit of decimal in it. Especially it might make sense in future to reduce the work-week by one day, so you got 4 days of work and the "normal" 2 day weekend.

> year of birth of a religious figure many people are more or less indifferent about.

> benefit of celebrating an event most modern people probably can relate to and are in favour of

I think more people care more /know more about Christmas than the French Revolution.

I'm not really convinced about metric system either. Sure, it has some nice properties, but it was created bit prematurely when science was really not developed enough to put solid foundations for a measurement system. It took some 150 years to make it somewhat usable (by establising SI), and even now the base units are bit silly. Now we are kinda stuck in the worse is better region because metric system is good enough and has almost impossible amount of inertia behind it.

You say you are not convinced but you give no explanation about why. Would you, please ?

Well, this paper has me convinced:

http://dozenalsociety.org.uk/pdfs/aitken.pdf

Of course, YMMV.

Exactly! The revolutionaries' error in this case was that they weren't revolutionary enough: they should have switched to a dozenal system. As it is, French revolutionary units are an imperfect compromise, with no really good argument for them other than 'almost every country in the world uses them.'

Base 12 is nice and I would prefer it over base 10. But that would probably been too big of a change to get actually implemented (especially globally) even during the tumults of french revolution, so that is not really my main gripe with metric system.

The most obvious problem is the definitions and "values" of the base units. The (current) defintions involve such nice round numbers like 299792458, 9192631770, 273.16, and so on. I can appreciate that nature might not allow aligning all the units in a perfectly harmoniuous matter, but surely we can do better than this.

Then there is of course the big kilogram debacle that we are still trying to figure out. In addition to the fact that it is defined via an artifact, it also is the only base unit with a prefix, mostly by accident.

While everything else in metric system is mostly nicely aligned with decimal system, the attempt to reform time failed, so we are stuck there with the legacy unit(s). I would had preferred to have the time base unit to be (roughly) 1/1000th of a day rather than 1/86400th of day. Admittedly basing time on earth rotation lacks certain degree of universality that other base units have, so maybe altogether different base would have been a good idea.

These days metric system is associated mostly with 10^(n*3) prefixes, but that is relatively new feature. That is something I would have liked to have from day 1 so that we wouldn't have a cacophony of centimeters and deciliters in common use.

Oh, and mentioning liters gets us to the confusing world of area and volume units. Originally metric system had a(c)res and liters, but then they noticed that they are not that great and switched to square and cubic meters. Except of course people didn't follow and I think in pretty much every metric country at least liters are still in common use.

It might have been a good idea to retain those specialized units, because of the ambiguity problems of prefixed sq/cu meters. At least personally I think it would be more convenient (if maybe not as elegant) that mm³ would be 10^-3 cubic meters instead of the current 10^-9 cubic meters. Now if we are sticking to the "main" prefixes, we don't have anything between mm³ (which is tiny amount) and m³ (which is large amount).

From a purely notational perspective, it would have been nice to have bit more consistency with the naming and symbols of the units and prefixes. Some of the units are named after people, some are not, so some of them have capital letter as symbol, others a lower-case. And to mix things up, some units (even base units) have two or three letter symbols. Of course ohms are the special snowflake that deserve a greek letter.

Prefixes mostly follow the rule that capitals are >0 and lowercases <0. Thats nice, except kilo strikes again as an exception. And again a greek letter sneaked in just to make sure that typesetting units remains a challenge. How many times have you seen µ substituted with a u?

I probably could go on, but yeah, it sure is not perfect system.

Reply on news.ycombinator.com