It’s ingrained and arbitrary. The only thing we’ve found so far for measuring time that doesn’t appear to be arbitrary is Planck time, which is so small it has no use in daily life. So if you have to use an arbitrary unit anyway, why make a new arbitrary unit? And while the second, minute, hour, and to a lesser degree month are arbitrary, days and years are not, they are just based on the unique circumstances of when we started observing our world in a scientific manner.
The SI unit for time is the second. It just happens to be the same length as the imperial second. Minutes, hours, days, weeks, months, and years are not SI units.
12, 24, and 60 are highly composite numbers and easily divisible by more numbers than 10. Also, if you are doing that, go ahead and redefine degrees in a circle and all that jazz too. Go ahead.
There has been a “metric” measurement of angles for a long time. The radian. It’s pi based instead of 10 based, but it makes way more sense than degrees.
Plank time is arbitrary too. Plank time is the time it takes light to move 1 Plank length. It’s no different than any other time measurement other than it’s the shortest measurable unit of time.
It’s arbitrary in the same way measuring the time between photon absorption/emission in a cesium atom is arbitrary or the rotation of our planet is arbitrary.
Picking the smallest is arbitrary just like picking a larger interval.
In the cesium clock case, you count 9192631770 because it’s close to 1 second we already are familiar with and arbitrarily say 9192631770 transitions is defined as 1 second.
For example Planck time is defined as 5.391247(60)×10−44 seconds. But what is that second? It’s the arbitrary 9192631770 cesium transitions we picked because it’s close to the second that come from Earth’s spin.
Planck time doesn’t appear to be arbitrary, but a feature of our universe, hence the shortest measurable unit of time. It’s length in seconds is arbitrary because seconds are arbitrary. And seconds are arbitrary because the only non-arbitrary unit of time we have found so far is too unwieldy to use for anything but scientific purposes, and it’s very unwieldy for many of those.
Because the day and year have meanings. They are “the time it gets for the earth to make a full rotation” and “the time to come full circle around the sun”. They are of varying length, so we actually use time periods that are almost the real day and year, and call them day and year. These are fixed length.
The second is arbitrary, because we just arbitrarily decided to split up the day in 24 hours, hours into 60 minutes and minutes into 60 seconds. Why 24/60/60? Kinda arbitrary.
Now, does arbitrary mean it’s bad? I don’t see why. The meter is defined in a similar manner, but using multiples of 10 instead of 24/60/60.
I know the meter and second have been redefined to be based on scientific phenomena and be independent from the earth, but their length has the same arbitrary origin. And as such, they are arbitrary.
I don’t see what being arbitrary has to do with being a good or bad unit of measurement.
It was created by the Babylonians, who had a base 12 numbering system. It’s no more arbitrary than base 10, and in fact superior in some ways. 12 can be evenly divided by 2, 3, 4, or 6. 10 can only be evenly divided by 2 and 5.
It’s ingrained and arbitrary. The only thing we’ve found so far for measuring time that doesn’t appear to be arbitrary is Planck time, which is so small it has no use in daily life. So if you have to use an arbitrary unit anyway, why make a new arbitrary unit? And while the second, minute, hour, and to a lesser degree month are arbitrary, days and years are not, they are just based on the unique circumstances of when we started observing our world in a scientific manner.
Because whole point of metric is to use powers of ten.
The SI unit for time is the second. It just happens to be the same length as the imperial second. Minutes, hours, days, weeks, months, and years are not SI units.
12, 24, and 60 are highly composite numbers and easily divisible by more numbers than 10. Also, if you are doing that, go ahead and redefine degrees in a circle and all that jazz too. Go ahead.
There has been a “metric” measurement of angles for a long time. The radian. It’s pi based instead of 10 based, but it makes way more sense than degrees.
In the days of doing math by hand, that might have mattered.
Let me introduce you to this little thing called a calculator.
Plank time is arbitrary too. Plank time is the time it takes light to move 1 Plank length. It’s no different than any other time measurement other than it’s the shortest measurable unit of time.
How is the shortest measurable amount of time it’s possible to measure with the physics of our universe arbitrary?
It’s arbitrary in the same way measuring the time between photon absorption/emission in a cesium atom is arbitrary or the rotation of our planet is arbitrary.
Picking the smallest is arbitrary just like picking a larger interval.
In the cesium clock case, you count 9192631770 because it’s close to 1 second we already are familiar with and arbitrarily say 9192631770 transitions is defined as 1 second.
For example Planck time is defined as 5.391247(60)×10−44 seconds. But what is that second? It’s the arbitrary 9192631770 cesium transitions we picked because it’s close to the second that come from Earth’s spin.
Planck time doesn’t appear to be arbitrary, but a feature of our universe, hence the shortest measurable unit of time. It’s length in seconds is arbitrary because seconds are arbitrary. And seconds are arbitrary because the only non-arbitrary unit of time we have found so far is too unwieldy to use for anything but scientific purposes, and it’s very unwieldy for many of those.
How is a unit that varies in time less arbitrary than units that at least have a fixed length?
Because the day and year have meanings. They are “the time it gets for the earth to make a full rotation” and “the time to come full circle around the sun”. They are of varying length, so we actually use time periods that are almost the real day and year, and call them day and year. These are fixed length.
The second is arbitrary, because we just arbitrarily decided to split up the day in 24 hours, hours into 60 minutes and minutes into 60 seconds. Why 24/60/60? Kinda arbitrary.
Now, does arbitrary mean it’s bad? I don’t see why. The meter is defined in a similar manner, but using multiples of 10 instead of 24/60/60.
I know the meter and second have been redefined to be based on scientific phenomena and be independent from the earth, but their length has the same arbitrary origin. And as such, they are arbitrary.
I don’t see what being arbitrary has to do with being a good or bad unit of measurement.
It was created by the Babylonians, who had a base 12 numbering system. It’s no more arbitrary than base 10, and in fact superior in some ways. 12 can be evenly divided by 2, 3, 4, or 6. 10 can only be evenly divided by 2 and 5.
I was referring to months which are arbitrary “to a lesser degree” but maybe I misunderstood the comment above mine
Seconds are defined as one gazillion times the Phase transition of some caesium atom, not the planck time.
Otherwise you are correct.