Our units of temporal measurement, from seconds on up to months, are so complicated, asymmetrical and disjunctive so as to make coherent mental reckoning in time all but impossible. Indeed, had some tyrannical god contrived to enslave our minds to time, to make it all but impossible for us to escape subjection to sodden routines and unpleasant surprises, he could hardly have done better than handing down our present system. It is like a set of trapezoidal building blocks, with no vertical or horizontal surfaces, like a language in which the simplest thought demands ornate constructions, useless particles and lengthy circumlocutions. Unlike the more successful patterns of language and science, which enable us to face experience boldly or at least level-headedly, our system of temporal calculation silently and persistently encourages our terror of time.
...It is as though architects had to measure length in feet, width in meters and height in ells; as though basic instruction manuals demanded a knowledge of five different languages. It is no wonder then that we often look into our own immediate past or future, last Tuesday or a week from Sunday, with feelings of helpless confusion. …
—Robert Grudin, Time and the Art of Living.
The units are complicated because our world is complicated. The moon orbits the earth in a certain interval, the earth orbit the sun and the earth revolves around itself. Those are the major points of reference but none of them line up.
Best of all, none of those natural reference values are constant. They drift gradually, and lunar months won’t be 30 days forever just like a day won’t be 24 hours in the future.
Hmm, I wonder… our current standard of time might end up being the standard for a long time, primarily because of GPS. Before we had global data networks it wasn’t really possible to syncronize clocks all around the world. There used to be a telephone service that you could dial which would tell you “The time is now eight fifty-five PM” or w/e because that was the most effective way to distribute a coordinated time signal, and then you could manually set your local clock/watch to match.
But GPS depends heavily on accurate time information, and keeping it accurate is very complicated. Relativitistic time dilation applies because the satellites are:
far enough away from Earth (~20000km) that they experience different gravity than devices on Earth’s surface, causing local time for the satellite to be be faster, and
moving so fast in their orbit that they experience a measurable slowing of local time.
(that’s right, using GPS on your phone is a real-world demonstration of the theory of relativity in practical effect)
…and all those satellites are constantly checking in with each other and ground stations to make sure they’re in agreement.
As a result there is now a de facto standard time reference for the entire world, and all networked devices depend on it for their own timing, and it is accurate to microseconds at worst.
100 years ago people were still winding mechanical clocks every day, and setting them by the local churchbell.
Yep. This stuff is surprisingly complicated, and that’s why we need to measure the day using a standardized unit instead of defining the unit with the day.
Incidentally, Wikipedia has a nice graph about the variation of the length of day. It’s surprisingly messy and pretty far from the ideals of antiquity.
The lunar month is currently ~29.5306 days (synodic, on average). Some day in the future (probably in a few million years), the average synodic moon cycle will reach 30 days (it is slowing down) - if, and that is a big if - we keep the current definition of “second” and “day”, because both the length of the day as well as the lenght of the year will have changed…
I suggest we switch to Planck based units. Just slap on a suitable multiplier to make the final unit practical in normal life and engineering. Basically like the mol unit but with a more precise and natural foundation.
If the fundamental constants of the universe aren’t exactly constant, we’re screwed and there are no good units.
The way we split them is still purely arbitrary though. We could have metric time that uses multiples of 10 just by adjusting the duration of a second accordingly and adjusting how we divide time in a day.
Days of the calendar would be more challenging. But it’s still possible to make something much more workable I’m sure of it.
Have a look at the international fixed calendar, used by kodak internally until 1989. 13 months of 28 days, it looks so clean
Everything months starts a Sunday (I’d rather start weeks on Monday but whatever), every second Monday is the 9th. Plus it has the advantage of keeping the 7 days week we’re used to. Software excluded, it looks easy to adopt.
When the metric system was defined and adopted during the French revolution they changed the calendar as well.
Months were changed to be 30 days each with an extra 5-6 days at the end of the year, weeks were 10 days long, days were 10 hours of 100 minutes, each minute lasted 100 seconds.
Unfortunately it did not stick and the decimal time system was reverted.
Yeah but can we talk about time?
As quoted in the GNU coreurils documentation for date input formats
The units are complicated because our world is complicated. The moon orbits the earth in a certain interval, the earth orbit the sun and the earth revolves around itself. Those are the major points of reference but none of them line up.
Best of all, none of those natural reference values are constant. They drift gradually, and lunar months won’t be 30 days forever just like a day won’t be 24 hours in the future.
Hmm, I wonder… our current standard of time might end up being the standard for a long time, primarily because of GPS. Before we had global data networks it wasn’t really possible to syncronize clocks all around the world. There used to be a telephone service that you could dial which would tell you “The time is now eight fifty-five PM” or w/e because that was the most effective way to distribute a coordinated time signal, and then you could manually set your local clock/watch to match.
But GPS depends heavily on accurate time information, and keeping it accurate is very complicated. Relativitistic time dilation applies because the satellites are:
(that’s right, using GPS on your phone is a real-world demonstration of the theory of relativity in practical effect)
…and all those satellites are constantly checking in with each other and ground stations to make sure they’re in agreement.
As a result there is now a de facto standard time reference for the entire world, and all networked devices depend on it for their own timing, and it is accurate to microseconds at worst.
100 years ago people were still winding mechanical clocks every day, and setting them by the local churchbell.
Yep. This stuff is surprisingly complicated, and that’s why we need to measure the day using a standardized unit instead of defining the unit with the day.
Incidentally, Wikipedia has a nice graph about the variation of the length of day. It’s surprisingly messy and pretty far from the ideals of antiquity.
Planck second is constant.
The lunar month is currently ~29.5306 days (synodic, on average). Some day in the future (probably in a few million years), the average synodic moon cycle will reach 30 days (it is slowing down) - if, and that is a big if - we keep the current definition of “second” and “day”, because both the length of the day as well as the lenght of the year will have changed…
I suggest we switch to Planck based units. Just slap on a suitable multiplier to make the final unit practical in normal life and engineering. Basically like the mol unit but with a more precise and natural foundation.
If the fundamental constants of the universe aren’t exactly constant, we’re screwed and there are no good units.
The way we split them is still purely arbitrary though. We could have metric time that uses multiples of 10 just by adjusting the duration of a second accordingly and adjusting how we divide time in a day.
Days of the calendar would be more challenging. But it’s still possible to make something much more workable I’m sure of it.
Have a look at the international fixed calendar, used by kodak internally until 1989. 13 months of 28 days, it looks so clean
Everything months starts a Sunday (I’d rather start weeks on Monday but whatever), every second Monday is the 9th. Plus it has the advantage of keeping the 7 days week we’re used to. Software excluded, it looks easy to adopt.
Alternatively there was the French revolutionary calendar with 10 days weeks and 12 months
But what is the week for, if not to measure work and rest days? With that in mind, 8 days (5 work, 3 rest) would be ideal.
When the metric system was defined and adopted during the French revolution they changed the calendar as well.
Months were changed to be 30 days each with an extra 5-6 days at the end of the year, weeks were 10 days long, days were 10 hours of 100 minutes, each minute lasted 100 seconds.
Unfortunately it did not stick and the decimal time system was reverted.