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A universal system of measures

Discussion in 'General Science Discussions' started by Yellow Fang, 25 Feb 2019.

  1. Yellow Fang

    Yellow Fang Veteran Geek

    Location:
    Reading
    I can't remember if I posted something along these lines before. I think the metric (SI) is better to work with than imperial. However, the basic units seem a bit sort of arbitrary. I think the original kilogram was the weight of a litre of water (maybe it wasn't). A degree Celsius is a hundredth of the difference between water's boiling and freezing point. A metre is a fraction of the earth's circumference iirc. These are not universal constants. I wondered what better units there may be. Iirc, there are 6 things to measure: length, time, mass, electric charge, temperature, and luminosity. I reckon the speed of light could be used to determine the distance unit if there was a good candidate for the time unit. The charge of an electron could be used as the unit for electrical charge. What would be the sensible multiplier: 10 like metric, 2 like computer science, e like in maths?
     
  2. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    I'm not precious about what unit of measurement I use or how it works but base 10 seems the logical choice for a number of reasons. Firstly it's the most common and almost everyone uses it. Also it stales well, which brings me on to the other important thing with units. They should be easily distinguishable over the most common use cases.

    I think temperature works best for that. 100 units between water freezing and boiling seems to get good manageable numbers for the most common temperatures we deal with. Likewise with time a second feels like a good short period of time and hours seem just a way of nicely dividing up the Earth's day. I could imagine a unit of 100 seconds becoming popular once we start living on other rocks with different day lengths.

    What we find as we advance though is it's how well we can define the smallest units really helps when working on small things. Fuzzy approximations don't really cut it when you are trying to calibrate high precious interments.

    So it's not so much about what is best, it's about clearly being able to define them against some constant which is easily repeatable and scaleable.
     
  3. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
  4. Yellow Fang

    Yellow Fang Veteran Geek

    Location:
    Reading
    Metric is a reasonable set of measures for practical purposes, but, just for fun, I was thinking what a more universal set of measurements would be. On the way home I wondered if Planck's Constant should have something to do with it. I looked it up on Wikipedia and I found out that the kilogram has already been redefined in terms of Planck's Constant. Before that a kilogram was defined by a metal cylinder in a French vault somewhere. Planck's constant is 6.62607015×10−34 J⋅s, which is the same as 6.62607004 × 10-34 m2 kg / s.

    What's a good unit for time?
     
  5. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
  6. amusicsite

    amusicsite dn ʎɐʍ sᴉɥ┴ Staff Member

    Location:
    UK
    Yellow Fang likes this.