3 ms·

The things that make the metric system superior to prior systems are: • Using a uniform set of prefixes to designate multiples and divisions of the base units.

by tzs 9mo ago

The things that make the metric system superior to prior systems are: • Using a uniform set of prefixes to designate multiples and divisions of the base units. Having one unit of say, volume (the liter), and then using prefixes when we need smaller or larger units is way better than having cups, pints, quarts, gallons, pecks, and many more. • Having those prefixes mean powers of 10. That fits in well with our use of decimal arithmetic. It is the first one that is most important. For temperature there's nothing actually 'Metric-y' about Celsius (or Kelvin), because in most cases people don't use multiples or divisions of the base unit. This includes in science and engineering. An astronomer would say (and write in their paper) that a star has a temperature of 7000 K, not 7 kiloK. They would say a neutron star has a core temperature of 100 trillion K, not 100 TK or 100 teraK. At the low end there is more use of prefixes. The scientists that work near absolute 0 do often use millikelvin and microkelvin. They also often don't. Both 10^-2 Kelvin and 10 mK would usually be acceptable. A metric system with the same meter, liter, and gram as the current one but that had picked F and R instead of C and K would work fine and be just as 'Metric-y' as the current metric system.

jrm4 9mo ago
What precisely is "better" about that? It's more predictable over -- some things that you don't know how they're going to scale? Again, the general thrust of "imperial" is better -- base your units on "utility of the most people using them the most for real life things" Do whatever you want for distances between stars, but no, walking off a room in "feet" can't be beat.
- tzs 9mo ago
  To pace off something in feet most people actually try to pace in yards and multiply by 3 if they want to express the result in feet. They could just as easily pace in meters. What is better with metric is the consistent way to name multiples and divisions of the base units. Metric uses power of 10 prefixes but another power could work fine. Power of 2 for example actually fits well with Imperial volume measurements, where a quart is 1/4 gallon, a pint is 1/2 quart, 1 cup is 1/2 pint, a fluid ounce is 1/8 cup, and a tablespoon is 1/2 a fluid ounce. Just make some prefixes that mean 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, and 1/256 and use those with gallon instead of having separate names for everything, and use the same prefixes with yards when you need a unit smaller than a yard and you'd be off to a good start. Add some prefixes that mean 2x, 4x, 8x, etc too. Yards and gallons don't have to be the base units. Could be feet and cups or anything else. The key is prefixes to get bigger or smaller units instead of naming those others units, and using the same prefixes across unit types.
  - jrm4 9mo ago
    [flagged]
    - pezezin 9mo ago
      > No, it is not easier to deal with meters if you're talking about physical spaces that humans inhabit. And it's not easier to deal with C when talking about the temperature of a room, because an F degree is just about the smallest difference a human can tell. I know I can tell a 74 from a 73 from a 72 etc in my house. Why? For anybody who grew up in a metric country, dealing with metres is pretty damn easy. Case in point, my GF is an architect working for an US military base, and she gets royally pissed off every time she has to deal with feet and inches.
- nayuki 9mo ago
  > Do whatever you want for distances between stars Actually, this is very problematic as well. As it stands, astronomical distances are quoted in single/thousands/millions/billions of kilometres, astronomical units (Earth-Sun distance), parsecs and kilo- and mega-, and then light-years (and thousands, millions, billions). I would strongly prefer to use metric units: metre, kilometre, megametre, gigametre, terametre (AU is around here), petametre (parsec and light-year is around here), exametre (about a thousand light-years), zettametre (about a million light-years), yottametre (about a billion light-years). The scale ends there because the observable universe is about 886 Ym in diameter.

by tzs 9mo ago

jrm4 9mo ago

What precisely is "better" about that? It's more predictable over -- some things that you don't know how they're going to scale? Again, the general thrust of "imperial" is better -- base your units on "utility of the most people using them the most for real life things" Do whatever you want for distances between stars, but no, walking off a room in "feet" can't be beat.

tzs 9mo ago
To pace off something in feet most people actually try to pace in yards and multiply by 3 if they want to express the result in feet. They could just as easily pace in meters. What is better with metric is the consistent way to name multiples and divisions of the base units. Metric uses power of 10 prefixes but another power could work fine. Power of 2 for example actually fits well with Imperial volume measurements, where a quart is 1/4 gallon, a pint is 1/2 quart, 1 cup is 1/2 pint, a fluid ounce is 1/8 cup, and a tablespoon is 1/2 a fluid ounce. Just make some prefixes that mean 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128, and 1/256 and use those with gallon instead of having separate names for everything, and use the same prefixes with yards when you need a unit smaller than a yard and you'd be off to a good start. Add some prefixes that mean 2x, 4x, 8x, etc too. Yards and gallons don't have to be the base units. Could be feet and cups or anything else. The key is prefixes to get bigger or smaller units instead of naming those others units, and using the same prefixes across unit types.
- jrm4 9mo ago
  [flagged]
  - pezezin 9mo ago
    > No, it is not easier to deal with meters if you're talking about physical spaces that humans inhabit. And it's not easier to deal with C when talking about the temperature of a room, because an F degree is just about the smallest difference a human can tell. I know I can tell a 74 from a 73 from a 72 etc in my house. Why? For anybody who grew up in a metric country, dealing with metres is pretty damn easy. Case in point, my GF is an architect working for an US military base, and she gets royally pissed off every time she has to deal with feet and inches.
nayuki 9mo ago
> Do whatever you want for distances between stars Actually, this is very problematic as well. As it stands, astronomical distances are quoted in single/thousands/millions/billions of kilometres, astronomical units (Earth-Sun distance), parsecs and kilo- and mega-, and then light-years (and thousands, millions, billions). I would strongly prefer to use metric units: metre, kilometre, megametre, gigametre, terametre (AU is around here), petametre (parsec and light-year is around here), exametre (about a thousand light-years), zettametre (about a million light-years), yottametre (about a billion light-years). The scale ends there because the observable universe is about 886 Ym in diameter.