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    (Original post by dragons_circle)
    I havn't seen any grads anywhere, usually radians are measurement of choice?
    It can be used in navagation, as there are 400 gradians in a circle if you have a bearing of 156 grads then something directly to the left will have the bearing 56 grads making mental arithmatic slightly easier
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    God made the world in 7 days. So it was only natural that we adopt a unit of measurement (1 week) after this time. The Earth rotates around the world in 52 weeks. So this becomes another unit of measurement. The year. We notice that there are 4 different times in this year with different weather. So this means that there are 3 months to a season.
    All of this helps to explain why God made the second.
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    One second isn't that long.
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    (Original post by planes12)
    who discovered that 1 second was that length of time like a nucleor atom pulses i guess every 1 second aswell i think. that's why we have atomic clocks as they never lose time.
    i dunno maybe an atom doesnt pulse like the length of 1 sec

    i am confused:p:

    like the sun is a 24hr thing but how did we come up with 1 second or anything.
    I'm sure no one 'discovered' the second. It's an arbitrary measure. As someone said, it's some ridiculous number of vibrations of the most common isotope of a caesium atom.

    Who decided the rising and setting of the sun (well, the Earth spinning on its axis) was 24 hours? Who decided a year was 365 days? In fact, if I remember correctly, it's 365 days, 6 hours, 9 minutes and 9.54 seconds. Why? Well, simply because that's what our less well informed ancestors decided and there's been no change into metric time yet. As for metres and so on, I think there's a bar of metal one metre long under standard temperature and pressure (298K, 1atm) in Paris or somewhere like that. Can't remember. That was arbitrary too.

    Circles aren't measured in degrees really, that's a bit of a baby measurement - circles are more commonly measured in radians (a radian is the angle subtended when the length of an arc is the same as the radius - hence its name, and there are 2*pi of them, or 6.28-ish, in a circle). That's a more 'natural' measure, because of the relationship between arc length and radius. But there is no 'natural' measure for time, because it's not bound by spatial constrictions. Curiously, light years are a very logical measure - a year is defined quite rigorously so as not to change substantially for all purposes, and the speed of light doesn't change. The only problem is that's a distance, not a time.

    If we were to make time 'metric' we should do it in years. We could measure most things in microyears or something - because the year is quite a large value, like the farad (SI unit of capacitance - microfarads are normally used because the farad is a huge capacitance). But the SI unit of time is a second, and although it's arbitrary we stick with it. Most of what we work with every day is arbitrary. Why do we use a base 10 number system? Because we have ten fingers? It's difficult (for those who have never tried) to imagine a base 12 number system, because we only have ten digits, but imagine for a second that A and B were not letters, but numbers - numbers after 9. Counting would go "1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1A, 1B, 20, ..., 99, 9A, 9B, A0, A1, ..., BA, BB, 100" and so on. That's perfectly sensible - it only might seem stupid because we're not used to it, but in fact binary (which uses only 1 and 0: "0, 1, 10, 11, 100, 101, 110, 111, 1000, 1001, 1010...") and hexadecimal (1-9, A, B, C, D, E, F) are used a lot in computing. It might be argued that you can only count up to 10 on your fingers, but that depends how you count.

    I can count up to 1023 on mine in binary. Can't say I do... but it's nice to show off.

    (Edit: horribly nerdy joke coming up... to all those who don't believe in counting binary on your hands, well, 132 is all I have to say to you. )
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    (Original post by generalebriety)
    I'm sure no one 'discovered' the second. It's an arbitrary measure. As someone said, it's some ridiculous number of vibrations of the most common isotope of a caesium atom.

    Who decided the rising and setting of the sun (well, the Earth spinning on its axis) was 24 hours? Who decided a year was 365 days? In fact, if I remember correctly, it's 365 days, 6 hours, 9 minutes and 9.54 seconds. Why? Well, simply because that's what our less well informed ancestors decided and there's been no change into metric time yet. As for metres and so on, I think there's a bar of metal one metre long under standard temperature and pressure (298K, 1atm) in Paris or somewhere like that. Can't remember. That was arbitrary too.

    Circles aren't measured in degrees really, that's a bit of a baby measurement - circles are more commonly measured in radians (a radian is the angle subtended when the length of an arc is the same as the radius - hence its name, and there are 2*pi of them, or 6.28-ish, in a circle). That's a more 'natural' measure, because of the relationship between arc length and radius. But there is no 'natural' measure for time, because it's not bound by spatial constrictions. Curiously, light years are a very logical measure - a year is defined quite rigorously so as not to change substantially for all purposes, and the speed of light doesn't change. The only problem is that's a distance, not a time.

    If we were to make time 'metric' we should do it in years. We could measure most things in microyears or something - because the year is quite a large value, like the farad (SI unit of capacitance - microfarads are normally used because the farad is a huge capacitance). But the SI unit of time is a second, and although it's arbitrary we stick with it. Most of what we work with every day is arbitrary. Why do we use a base 10 number system? Because we have ten fingers? It's difficult (for those who have never tried) to imagine a base 12 number system, because we only have ten digits, but imagine for a second that A and B were not letters, but numbers - numbers after 9. Counting would go "1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1A, 1B, 20, ..., 99, 9A, 9B, A0, A1, ..., BA, BB, 100" and so on. That's perfectly sensible - it only might seem stupid because we're not used to it, but in fact binary (which uses only 1 and 0: "0, 1, 10, 11, 100, 101, 110, 111, 1000, 1001, 1010...") and hexadecimal (1-9, A, B, C, D, E, F) are used a lot in computing. It might be argued that you can only count up to 10 on your fingers, but that depends how you count.

    I can count up to 1023 on mine in binary. Can't say I do... but it's nice to show off.

    (Edit: horribly nerdy joke coming up... to all those who don't believe in counting binary on your hands, well, 132 is all I have to say to you. )
    WOW:eek: that's a really good read i enjoyed reading it, although i am always confused when it comes to maths:p: .
 
 
 
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