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Excellent question. I assumed that one mars minute differs from an earth minute but I just learned that they don't. Seconds, minutes and hours are universal. H
by Timothycquinn 8y ago
Excellent question. I assumed that one mars minute differs from an earth minute but I just learned that they don't. Seconds, minutes and hours are universal. Hours in a day is what varies by planets, moons etc. Funny that I never thought of that before :)
- jordz 8y agoSurely this is effected by relativity? Edit: Or rather should I say it’s relative... (lol?)
- Evidlo 8y agoIt just depends on what your definition of a Martian minute is. If you define it as 1/(24*60) of a Martian day, it is different from an Earth minute.
- m3at 8y agoYou're likely joking, but just in case: on earth the second is not defined as a fraction of the day, it's a SI unit defined as a constant count of energy level variations of an caesium-133 atom.
- justinator 8y agoWhat came first, the definition/concept/time span of a second, or the discovery of the Caesium-133 atom?
- m3at 8y agoGood question. Counting minutes obviously came first as devices likes hourglass and water clocks are old (2000 BCE). Regarding their precision, I got interested and per this paper [1] and the wikipedia page about traditional Chinese timekeeping [2], water clocks from two millennia ago might have around 15min precision. For second level precision, it seems modern mechanical clocks were required, and they only precede the discovery of caesium by a few centuries. [1] https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S025292110010586X https://www.cambridge.org/core/services/aop-cambridge-core/c... [2] https://en.m.wikipedia.org/wiki/Traditional_Chinese_timekeeping https://en.m.wikipedia.org/wiki/Traditional_Chinese_timekeep...
- mehrdadn 8y agoThey said minute, not second. Even on Earth a minute isn't always 60 seconds.
- Timothycquinn 8y agoHow is this? According to the International System of Units, a minute is 60 seconds.
- mehrdadn 8y agoLeap seconds.
- gizmo686 8y agoA minute is still 60 seconds. The only difference is that some clocks will occasiomally go an entire minute without incrementing their minute counter. This is a property of the map, not the territory.
- mehrdadn 8y agoYou're choosing to define it that way when the entire point made here was that other people can and do define it other ways.
- dullgiulio 8y agoThey change the duration of the day, not the minute.
- mehrdadn 8y agoThe clock goes from 59:59 to 59:60...
- icebraining 8y agoYeah. Or they smear it over a longer time period, but that still (slightly) extends the duration of each minute.
- Timothycquinn 8y agoThanks for that clarification. After this, I was able to find the International System of Units Wikipedia page which clearly defines a second as per your summary. It's a relief to see that it's a constant formula like that of the Kilogram.
- craftyguy 8y agoI was suprised to learn (from the wiki page) that the kelvin, mole, and ampere do not have exact numerical definitions yet, though I guess that's expected to change in May of this year. And then there's the candela, still basically defined by how luminous whale blubber is when it is burning: > Current (1979): The luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 5.4×1014 hertz and that has a radiant intensity in that direction of 1 / 683 watt per steradian. > Note: both old and new definitions are approximately the luminous intensity of a whale blubber candle burning modestly bright, in the late 19th century called a "candlepower" or a "candle".
- kevingrahl 8y agoWhat happens in May?
- craftyguy 8y agoWorld Metrology Day, where acceptance of these standards will be voted on. https://www.nist.gov/news-events/news/2018/11/historic-vote-ties-kilogram-and-other-units-natural-constants https://www.nist.gov/news-events/news/2018/11/historic-vote-...
- sidcool 8y agoNot if we take gravitational time dilation into account. But for most practical purposes between Earth and Mars, a minute will be the same.
- presscast 8y ago>Not if we take gravitational time dilation into account. I think most of us will be observing the minute of silence from Earth, either way ;)