11 ms·
Units of time are specifically chosen to have 5, 2, and 3 as factors. It doesn't look so pretty when you compare with universal fundamentals: > 1.000692286 mil
by greenleafjacob 9y ago
Units of time are specifically chosen to have 5, 2, and 3 as factors. It doesn't look so pretty when you compare with universal fundamentals:
> 1.000692286 milliseconds – time taken for light to travel 300 km in a vacuum
- gerdesj 9y ago60 is the really important number. It does happen to have rather a lot of convenient factors. Cheers Babylon. (I have checked the assertion and it is correct)
- ngcc_hk 9y agoFinally less hate if barbarian. Sorry Babylonian. 10 hour 10 second easier. A quarter pass 7. (Actual 12 is a human number of look from earth. Both chi-na and ... is it a copy.)
- stephengillie 9y agoIt's always bugged me there's no "metric time". 1 metric minute = 100 seconds = 1.667 Babylonian minutes 1 metric hour = 100 metric minutes = 166.7 Babylonian minutes = 2.78 Babylonian hours. 1 day = 8.61 metric hours = 1436 Babylonian minutes = 23.93 Babylonian hours. Thoughts?
- todd8 9y agoI've always thought that if we are redefining time units a better solution might be 100000 metric seconds in a day (making them a bit shorter than the existing 86400 in a day) and otherwise the same relationships you've suggested: 1 metric minute = 100 metric seconds 1 metric hour = 100 metric minutes 1 day = 10 metric hours.
- VMG 9y agoIf rather switch to a base-12 number system
- theoh 9y agohttps://en.wikipedia.org/wiki/Decimal_time https://en.wikipedia.org/wiki/Decimal_time
- collinmanderson 9y agoI believe they split up a circle into 360 degrees because it's close to the number of days in the year.
- TekMol 9y agoUnits of time are specifically chosen to have 5, 2, and 3 as factors. Why not 4?
- tehlike 9y ago4=2^2?
- greenleafjacob 9y agoI think that is fair as well. 60/4=15 but 30/4 is not a whole number.
- gerdesj 9y agoNo it isn't but a quarter of a half hour is still understandable and is seven and one half minutes which is 7' 30". The ancient Babylonian idea of using 60 (and 360 for angles) is absolute genius. If you think about it, it is a bit weird but makes so much sense working in base 60. We all do it all of the time.
- collinmanderson 9y agoI believe 360 for angles came from 365 days in a year.
- jacquesm 9y agoBecause you want prime factors.
- arnarbi 9y ago60 is indeed handy since it divides into 2, 3, 4, 5, and 6. 30 would be much less convenient. Better to drop the 5 (as evidenced by 12 and 24) I think the gp just generalized a bit to much. Units of time weren't chosen for those (prime) factors. People had simply figured out long time ago that a dozen is a nice round number.
- mkl 9y ago300km is the wrong number. Metres are defined based on the speed of light, and it's 299,792,458 m/s (not pretty!). This is for historical compatibility reasons, and without any goal of nice factors. It takes exactly 1 ms for light to travel 299.792458 km. Physicists often use "natural" units [1] where the speed of light is 1. [1] https://en.wikipedia.org/wiki/Natural_units https://en.wikipedia.org/wiki/Natural_units
- konschubert 9y agoThe speed of light in natural units is 1c. Usually people omit c because it's power can be inferred. And then they fail to mention to students that they're just omitting the c, causing a hilarious amount of confusion, half-truths and cargo-culting on the topic of natural units... ------ Saying that the speed of light in natural units is 1 is like saying that one meter in SI units is 1. (s, m, kg, 10) can be seen as basis vectors of a vector space. (Multiplication is "addition", power is "multiplication".) Another base of this vector space is (h, c, GeV, 10).
- mkl 9y agoTrue. We're talking about the prettiness and factors of the numerical values, and the terms in the original hyperfactorial don't have units at all.
- adrusi 9y agoThe speed of light has the dimension distance/time. Distance is a relative measure of space (length, height, depth), time is a measure of... time. When we talk about relativity, the distinction between space and time isn't very useful, so those are actually the same kind of measure. So distance/time is the same thing as distance/distance or time/time or 1. I suspect this is precisely the half truths and cargo cutting you're referring to. Maybe you could explain what the problem here is.
- konschubert 9y ago*its
- monochromatic 9y agoSlightly off topic, but my favorite units for c are feet per nanosecond. In those units c = 1 (plus or minus a couple of percent).
- 18nleung 9y agoThat's really interesting - only about 2% off. Conversion Here: https://www.wolframalpha.com/input/?i=speed+of+light+in+feet+per+nanosecond https://www.wolframalpha.com/input/?i=speed+of+light+in+feet...
- contravariant 9y agoIt's even closer if you use a 'metric foot' of exactly 30 cm. Then you're only off by 0.1%.
- monochromatic 9y ago> metric foot Why is that a thing?
- sixothree 9y agoMaybe because 30cm is very close to 12 inches.
- contravariant 9y agoNot sure, but most of those 'metricised' units are leftovers from Napoleon's push to make everything metric.
- letlambda 9y agoWhich leads to my favorite way to think about it. One foot per clock tick of a 1Ghz processor.
- stephengillie 9y agoDoes this mean circuits in a 1 GHz processor can't be longer than 12 inches?
- zokier 9y agoSpeed of light is by choice too; the numerical value is in no way "fundamental"