10 ms·

I love how the example is super confusing. You sleep 3.33… metric hours. You fall asleep 9:50 metric time. You'd think we can just interchange the . and : so

by toxik 3y ago

I love how the example is super confusing. You sleep 3.33… metric hours. You fall asleep 9:50 metric time. You'd think we can just interchange the . and : so you should wake up 12:83…, or 2:83… the next day. But no, it's apparently 2:75 metric time. Why? Also nice how they IMMEDIATELY ran into a continuing fraction 1/3, which is exactly the point of the 60-minute hour, 24-hour day, or 360-degree circle: lots of factors.

mirekrusin 3y ago
We need tau-rational-time! We sleep for τ/3, noon is at π.
- femto 3y ago
  Spreadsheets already use "τ time", in that a day is a single unit, which could easily be defined to be "τ".
- bmacho 3y ago
  An hour is just an another name for a deciturn, or a deciday. Tau is not a good unit for angles in general, unless you have circles, or you need lengths of circumferences somewhere. (You want to paint your clock and calculate the amount of paint, or something.) Turn is the natural angle unit. And since the earth rotates 1 turn/day, the amount of turns is the same as the amount of days.
  - bmacho 3y ago
    I meant radian, not tau.
- tomjakubowski 3y ago
  You can start the movement by announcing "it's pie o'clock" at lunch time every day
Entalpi 3y ago
Its like we have built our entire lives around another time system! /s You get similar problems converting between Freedom degrees and Celsius. Its just what people have built an understanding of.
- pipo234 3y ago
  To quote yet another time format: NTP 64-bit timestamp format (rfc8877), which is 32 bits seconds since epoch + 32 bits fixed point second fractions. (Outside of Network Time Protocol, you'll find this baby for instance in ISOBMFF ProducerReferenceTimeBox(prft)). Here seconds are just 1/(24*60*60) of a day as expected, but the base 2 fixed point part, where a tick "is roughly equal to 233 picoseconds" makes you want to pull your hairs out if you just want to accurately express milliseconds. (Similarly for other timescales frequently used in media processing, like 90kHz, 25, 60 or 29.97) The answer to all this is of course: hand waving — "you don't need that". Your time can be perfectly accurate in itself (ie. an accurate discrete sample of continuous time), even if no accurate conversion exists to some other time system.
- toxik 3y ago
  I disagree, it’s not equal but different. The French famously tried to switch to a decimal system for angles before, but failed in no small part because of the relatively few unique prime factors. Being able to divide evenly by three turns out to be more important than five.
- pif 3y ago
  You meant "Fahrenheit" rather than "Freedom", didn't you?
  - gorlilla 3y ago
    I think they said what _they_ meant _and_ still meant what _you_ said.
    - pif 3y ago
      Is this a common joke?
L3viathan 3y ago
> Also nice how they IMMEDIATELY ran into a continuing fraction 1/3, which is exactly the point of the 60-minute hour, 24-hour day, or 360-degree circle: lots of factors. While I agree in principle, this example is not evidence of it. It's not like we measured the amount of sleep needed and it's precisely 8 hours. A more reasonable thing to say would be: You need to sleep for 3.5 metric hours.
- tomtomtom777 3y ago
  Exactly. The exact amount of sleep needed on average is almost certainly an irrational number. (Because almost every number is irrational)
  - Karellen 3y ago
    Are you sure? Isn't the average calculated by dividing by n, an integer? Edit: I mean, you're right that nearly every number is irrational. But I think averages are going to be some of the tiny fraction of numbers that aren't.
    - red_trumpet 3y ago
      Only if you take an average of rational numbers. Like e/2 is still irrational.
      - ReleaseCandidat 3y ago
        While in theory you could measure sleeping time in fractions of 2 pi, I'd guess that you're using rational numbers in the actual calculation anyways.
        red_trumpet 3y ago
        Why would sleeping time be a fraction of 2pi? > I'd guess that you're using rational numbers in the actual calculation anyways. Well, actually one uses floating point arithmetic, which isn't rational numbers either (as shown by the classic example a = 1/3, b = 3*a, then b != a)
pmontra 3y ago
I didn't check the details of that metric time system but there would be no problem living a 10 hours day with 100 minutes hours and 100 seconds minutes. The second would be defined with a different number of "cycles of the radiation produced by the transition between two levels of the cesium-133 atom" and that's all. Instead of rounding our lives at "our" quarters of hours or ten minutes, five minutes marks we would round to the metric quarters of hours, maybe eights of hours (we could have found a name for that, like for coins) etc, and nobody would notice because that would be what we are born with. Similarly, people buy 50 cm x 70 cm frames in metric countries and 20" x 30" frames in the USA. Nobody thinks about that except frame factories in China, that have to cut them in two sizes.
- toxik 3y ago
  Nobody questions the logical consistency of the system, I think. Presently, we use 24-hour time (AM/PM or otherwise), so the loss in precision is enormous going from 24 to 10. Think about it. A tenth of a standard hour is 6 standard minutes. A tenth of a metric hour is 144 standard minutes, more than two standard hours. A hundredth of a standard hour is 36 standard seconds, or half a minute. It is in the context of hours a negligible amount of time. A hundredth of a metric hour is 14.4 standard minutes! Imagine being 0.01 metric hours late for a meeting. So everywhere you now have to specify time to two decimal places /at least/, three to have sub-standard-minute precision. Layer on top of this the fact that the new system has significantly fewer distinct prime factors, so you quickly run into continuing fractions. Disaster.
  - ivanbakel 3y ago
    What? A metric hour is 144 standard minutes - or do you imagine that a day of metric hours is 1441010 = 144,000 standard minutes long? A tenth of a metric hour is 14.4 standard minutes. A hundredth of a standard hour is 1.44 minutes. Being 0.01 metric hours late, or 1 metric minute late, is not too much more than being 1 standard limit late. And current time is specified to 6 digits for second precision - hours, minutes, and seconds.
  - taeric 3y ago
    Don't we have the same basic criticism going from Fahrenheit to Celsius? You go from a 10 degree swing being big to ridiculously huge. That is, arbitrary number is arbitrary, at large. Most of the "benefits" of any system won't actually be realized by most people that are using it. Consistency, on the other hand, is hugely important.
Denvercoder9 3y ago
> You'd think we can just interchange the . and : so you should wake up 12:83…, or 2:83… the next day. > But no, it's apparently 2:75 metric time. Why? You can, they just messed up the example by unnecessarily rounding off the times. The night from 9:50 till 2:75 metric time only lasts 3.25 metric hours, or 7h48m in standard time; less than the 8 standard hours they started with.
eps 3y ago
Come to think of it, being able to cleanly divide a minute or an hour into 2, 3, 4, 5 and 6 equal parts is pretty damn handy.
- Jleagle 3y ago
  Don't forget 10, 12, 15, 20, 30
  - gorlilla 3y ago
    It's almost like circles are the perfect shape for sliced pies afterall.
- bmacho 3y ago
  Yes. That's why I love metric clock, the number '5' screams 1/2 to me, and '3.33' screams 1/3 much more than 6 and 4 do.
- prometheus76 3y ago
  Now apply the same logic to measurement, and you'll see why it's so handy to use a dozenal foot for fabricating things.
  - rplnt 3y ago
    Is 1/3 (1/6) such an important concept? 1/2 (1/4) is natural in metric. I would think a bigger benefit is that you can drop up and down without any math depending on the precision you need. Or use decimals, no math involved either, since it's the same thing.
    - somestag 3y ago
      Yes, 1/3 and 1/6 are quite important. Do enough making and you will run into those fractions plenty. It just turns out that in practice, as you say, easy unit conversions outweigh the benefit of clean division. Metric's important benefit is that it's a consistent base, not that it's specifically base-10. And now that we use computers for a lot of measurement, those infinite decimals aren't as big of a deal. (Well, most of the time, anyway. Representation of infinite fractions famously creates some programming problems. But I mean for the user making the measurement.) Base-10 is easy to learn since it's the same we use for counting, but I think there's an interesting argument to be made that purely from a science/engineering/making perspective it would be better to use a consistent base-12 measurement system.
jader201 3y ago
It’s too bad it doesn’t take exactly 360 days for the earth to orbit the Sun. We should do something about that.
- FabHK 3y ago
  Yes. A good creator would’ve made the year 360 days long and given us 12 fingers. Now we should fix it with some astroengineering and bioengineering.
evrydayhustling 3y ago
Metric time is about factors too, but it prioritizes the factors that simplify the comparison across (literally) many orders of magnitude. This is way less helpful for everyday life because we usually only reason within 2-3 orders of magnitude, but we deal with tons of harmonic subcycles that the 24h clock makes easy. For a fun, a more justified usage of metric time, check out Vernor Vinge's "A Deepness in the Sky" (also IMO one of the best sci-fi novels of all time). A spacefaring humanity that stretches their life across journeys and projects that span centuries, and which has to artificially produce their own daily cycles, gets a lot more value out of metric time.
- peheje 3y ago
  Wasn't a big fan of "A Fire Upon the Deep", should I continue on and read "A Deepness in the Sky"? A while since I read it, but in short I disliked the characters which I could not symphatize with. The dog story (which started out great) and the humor wasn't me either.
  - evrydayhustling 3y ago
    I'm a huge fan of both, but you're not the first person I've heard who had problems with the writing style / dialogue / characterization of Fire. In that respect, I'm not sure Deepness will feel different. Vinge has a pretty consistent style and cultural stance, which IMO is an interesting balance of Heinlein-style techno-libertarianism and genuine "humanism" (which extends to dogs, plants, and other thinking creatures). Structurally, though, it's pretty different. The characters have much more opportunity to develop, and it's purely hard sci-fi where Fire used its setting to veer into fantasy ideas. So my biased advice remains: give it a shot :)
    - peheje 3y ago
      Thanks for your time in giving response. I'll give it a go!
- bglusman 3y ago
  Came here to mention/contrast Vinge's metric time with with my (quick, approximate) understanding of this approach... The problem with this approach is it attempts to "redefine" hours and minutes... part of what I liked in Vinge's/Deepness' approach was, it ignored all that and just talked about seconds in standard exponential scientific notation... it makes a lot more sense in space though, where there's no need/logic to connecting or synchronize to a specific solar cycle, so they just think/talk in kilo-seconds (about 40 mins) and mega-seconds (about 11.6 days)... or at least those are the two I recall them using enough that I got semi-used to thinking in them while reading the book... I had to convert, but I didn't have to redefine any existing unit or remember/remind myself which meaning of hour/minute they're using, because nothing changed.
bena 3y ago
You know what other measuring system is based around highly composable numbers? It's not metric. It's the imperial system. Halves, thirds, quarters are all neat numbers. It does get a little weird because we only use feet, yards, and miles today, but there is a progression from inch to mile that all make sense to some degree. Similarly with volumes. You can get from teaspoon to gallon without having to worry about any weird decimals. The only thing metric really has going for it is uniformity of conversion. People shit on it, but the imperial system is not actually that horrible.

by toxik 3y ago

mirekrusin 3y ago

We need tau-rational-time! We sleep for τ/3, noon is at π.

femto 3y ago
Spreadsheets already use "τ time", in that a day is a single unit, which could easily be defined to be "τ".
bmacho 3y ago
An hour is just an another name for a deciturn, or a deciday. Tau is not a good unit for angles in general, unless you have circles, or you need lengths of circumferences somewhere. (You want to paint your clock and calculate the amount of paint, or something.) Turn is the natural angle unit. And since the earth rotates 1 turn/day, the amount of turns is the same as the amount of days.
- bmacho 3y ago
  I meant radian, not tau.
tomjakubowski 3y ago
You can start the movement by announcing "it's pie o'clock" at lunch time every day

Entalpi 3y ago

Its like we have built our entire lives around another time system! /s You get similar problems converting between Freedom degrees and Celsius. Its just what people have built an understanding of.

pipo234 3y ago
To quote yet another time format: NTP 64-bit timestamp format (rfc8877), which is 32 bits seconds since epoch + 32 bits fixed point second fractions. (Outside of Network Time Protocol, you'll find this baby for instance in ISOBMFF ProducerReferenceTimeBox(prft)). Here seconds are just 1/(24*60*60) of a day as expected, but the base 2 fixed point part, where a tick "is roughly equal to 233 picoseconds" makes you want to pull your hairs out if you just want to accurately express milliseconds. (Similarly for other timescales frequently used in media processing, like 90kHz, 25, 60 or 29.97) The answer to all this is of course: hand waving — "you don't need that". Your time can be perfectly accurate in itself (ie. an accurate discrete sample of continuous time), even if no accurate conversion exists to some other time system.
toxik 3y ago
I disagree, it’s not equal but different. The French famously tried to switch to a decimal system for angles before, but failed in no small part because of the relatively few unique prime factors. Being able to divide evenly by three turns out to be more important than five.
pif 3y ago
You meant "Fahrenheit" rather than "Freedom", didn't you?
- gorlilla 3y ago
  I think they said what _they_ meant _and_ still meant what _you_ said.
  - pif 3y ago
    Is this a common joke?

L3viathan 3y ago

> Also nice how they IMMEDIATELY ran into a continuing fraction 1/3, which is exactly the point of the 60-minute hour, 24-hour day, or 360-degree circle: lots of factors. While I agree in principle, this example is not evidence of it. It's not like we measured the amount of sleep needed and it's precisely 8 hours. A more reasonable thing to say would be: You need to sleep for 3.5 metric hours.

tomtomtom777 3y ago
Exactly. The exact amount of sleep needed on average is almost certainly an irrational number. (Because almost every number is irrational)
- Karellen 3y ago
  Are you sure? Isn't the average calculated by dividing by n, an integer? Edit: I mean, you're right that nearly every number is irrational. But I think averages are going to be some of the tiny fraction of numbers that aren't.
  - red_trumpet 3y ago
    Only if you take an average of rational numbers. Like e/2 is still irrational.
    - ReleaseCandidat 3y ago
      While in theory you could measure sleeping time in fractions of 2 pi, I'd guess that you're using rational numbers in the actual calculation anyways.
      - red_trumpet 3y ago
        Why would sleeping time be a fraction of 2pi? > I'd guess that you're using rational numbers in the actual calculation anyways. Well, actually one uses floating point arithmetic, which isn't rational numbers either (as shown by the classic example a = 1/3, b = 3*a, then b != a)

pmontra 3y ago

I didn't check the details of that metric time system but there would be no problem living a 10 hours day with 100 minutes hours and 100 seconds minutes. The second would be defined with a different number of "cycles of the radiation produced by the transition between two levels of the cesium-133 atom" and that's all. Instead of rounding our lives at "our" quarters of hours or ten minutes, five minutes marks we would round to the metric quarters of hours, maybe eights of hours (we could have found a name for that, like for coins) etc, and nobody would notice because that would be what we are born with. Similarly, people buy 50 cm x 70 cm frames in metric countries and 20" x 30" frames in the USA. Nobody thinks about that except frame factories in China, that have to cut them in two sizes.

toxik 3y ago
Nobody questions the logical consistency of the system, I think. Presently, we use 24-hour time (AM/PM or otherwise), so the loss in precision is enormous going from 24 to 10. Think about it. A tenth of a standard hour is 6 standard minutes. A tenth of a metric hour is 144 standard minutes, more than two standard hours. A hundredth of a standard hour is 36 standard seconds, or half a minute. It is in the context of hours a negligible amount of time. A hundredth of a metric hour is 14.4 standard minutes! Imagine being 0.01 metric hours late for a meeting. So everywhere you now have to specify time to two decimal places /at least/, three to have sub-standard-minute precision. Layer on top of this the fact that the new system has significantly fewer distinct prime factors, so you quickly run into continuing fractions. Disaster.
- ivanbakel 3y ago
  What? A metric hour is 144 standard minutes - or do you imagine that a day of metric hours is 1441010 = 144,000 standard minutes long? A tenth of a metric hour is 14.4 standard minutes. A hundredth of a standard hour is 1.44 minutes. Being 0.01 metric hours late, or 1 metric minute late, is not too much more than being 1 standard limit late. And current time is specified to 6 digits for second precision - hours, minutes, and seconds.
- taeric 3y ago
  Don't we have the same basic criticism going from Fahrenheit to Celsius? You go from a 10 degree swing being big to ridiculously huge. That is, arbitrary number is arbitrary, at large. Most of the "benefits" of any system won't actually be realized by most people that are using it. Consistency, on the other hand, is hugely important.

Denvercoder9 3y ago

> You'd think we can just interchange the . and : so you should wake up 12:83…, or 2:83… the next day. > But no, it's apparently 2:75 metric time. Why? You can, they just messed up the example by unnecessarily rounding off the times. The night from 9:50 till 2:75 metric time only lasts 3.25 metric hours, or 7h48m in standard time; less than the 8 standard hours they started with.

eps 3y ago

Come to think of it, being able to cleanly divide a minute or an hour into 2, 3, 4, 5 and 6 equal parts is pretty damn handy.

Jleagle 3y ago
Don't forget 10, 12, 15, 20, 30
- gorlilla 3y ago
  It's almost like circles are the perfect shape for sliced pies afterall.
bmacho 3y ago
Yes. That's why I love metric clock, the number '5' screams 1/2 to me, and '3.33' screams 1/3 much more than 6 and 4 do.
prometheus76 3y ago
Now apply the same logic to measurement, and you'll see why it's so handy to use a dozenal foot for fabricating things.
- rplnt 3y ago
  Is 1/3 (1/6) such an important concept? 1/2 (1/4) is natural in metric. I would think a bigger benefit is that you can drop up and down without any math depending on the precision you need. Or use decimals, no math involved either, since it's the same thing.
  - somestag 3y ago
    Yes, 1/3 and 1/6 are quite important. Do enough making and you will run into those fractions plenty. It just turns out that in practice, as you say, easy unit conversions outweigh the benefit of clean division. Metric's important benefit is that it's a consistent base, not that it's specifically base-10. And now that we use computers for a lot of measurement, those infinite decimals aren't as big of a deal. (Well, most of the time, anyway. Representation of infinite fractions famously creates some programming problems. But I mean for the user making the measurement.) Base-10 is easy to learn since it's the same we use for counting, but I think there's an interesting argument to be made that purely from a science/engineering/making perspective it would be better to use a consistent base-12 measurement system.

jader201 3y ago

It’s too bad it doesn’t take exactly 360 days for the earth to orbit the Sun. We should do something about that.

FabHK 3y ago
Yes. A good creator would’ve made the year 360 days long and given us 12 fingers. Now we should fix it with some astroengineering and bioengineering.

evrydayhustling 3y ago

Metric time is about factors too, but it prioritizes the factors that simplify the comparison across (literally) many orders of magnitude. This is way less helpful for everyday life because we usually only reason within 2-3 orders of magnitude, but we deal with tons of harmonic subcycles that the 24h clock makes easy. For a fun, a more justified usage of metric time, check out Vernor Vinge's "A Deepness in the Sky" (also IMO one of the best sci-fi novels of all time). A spacefaring humanity that stretches their life across journeys and projects that span centuries, and which has to artificially produce their own daily cycles, gets a lot more value out of metric time.

peheje 3y ago
Wasn't a big fan of "A Fire Upon the Deep", should I continue on and read "A Deepness in the Sky"? A while since I read it, but in short I disliked the characters which I could not symphatize with. The dog story (which started out great) and the humor wasn't me either.
- evrydayhustling 3y ago
  I'm a huge fan of both, but you're not the first person I've heard who had problems with the writing style / dialogue / characterization of Fire. In that respect, I'm not sure Deepness will feel different. Vinge has a pretty consistent style and cultural stance, which IMO is an interesting balance of Heinlein-style techno-libertarianism and genuine "humanism" (which extends to dogs, plants, and other thinking creatures). Structurally, though, it's pretty different. The characters have much more opportunity to develop, and it's purely hard sci-fi where Fire used its setting to veer into fantasy ideas. So my biased advice remains: give it a shot :)
  - peheje 3y ago
    Thanks for your time in giving response. I'll give it a go!
bglusman 3y ago
Came here to mention/contrast Vinge's metric time with with my (quick, approximate) understanding of this approach... The problem with this approach is it attempts to "redefine" hours and minutes... part of what I liked in Vinge's/Deepness' approach was, it ignored all that and just talked about seconds in standard exponential scientific notation... it makes a lot more sense in space though, where there's no need/logic to connecting or synchronize to a specific solar cycle, so they just think/talk in kilo-seconds (about 40 mins) and mega-seconds (about 11.6 days)... or at least those are the two I recall them using enough that I got semi-used to thinking in them while reading the book... I had to convert, but I didn't have to redefine any existing unit or remember/remind myself which meaning of hour/minute they're using, because nothing changed.

bena 3y ago

You know what other measuring system is based around highly composable numbers? It's not metric. It's the imperial system. Halves, thirds, quarters are all neat numbers. It does get a little weird because we only use feet, yards, and miles today, but there is a progression from inch to mile that all make sense to some degree. Similarly with volumes. You can get from teaspoon to gallon without having to worry about any weird decimals. The only thing metric really has going for it is uniformity of conversion. People shit on it, but the imperial system is not actually that horrible.