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| why is the US not Metric |
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| bsfeechannel:
--- Quote from: Altair8800 on November 08, 2019, 10:56:42 am ---Case in point, doing serious calculating Science/Engineering problems in US Customary Units is unnecessary hard (due to all the conversions you have to do and often you have to look up the conversion factors to be double certain) and as a result you have more greater chance of making errors (than working in Metric/MKS/SI). I recall getting one question wrong because I had to convert from PSI to lbf/ft^2. I think after that I started to convert all US Customary Units immediately to Metric MKS (Metre, Kilogram, Second). Do the maths, then I know I was guaranteed a MSK final result (like Pa/Pascal, N/Newton, J/Joule, W/Watt, etc.) then use the conversion tables to convert what ever the question asked. Sometimes at the end when I convert my metric result back to US Customary Units I might get some result like 4.99948, which I would just round to 5.000. A small few of my professors were not pleased me doing calculations this way, but couldn't complain to much because I got the correct result in the end... I view doing serious calculations in US Customary Units vs in Metric like doing calculations by hand vs using a calculator. Yes it can be done, but it is more time and more chance of error. And it sucks when you know there is a better way... Thanks again... :) --- End quote --- This is something some guys can't understand. The customary system has several units to measure essentially the same thing, using different number bases. So it's not enough to base those units on the SI and claim that metrication is done. One of the aims of the metric system is to reduce conversions to a minimum, so reducing the chance of error and its propagation. It's a well thought out system that integrates science, engineering, technology and everyday usage in a single standard, reflecting the times we are living. Imperial is a cobbled up system of traditional units that looks and smells like a bygone era. |
| bsfeechannel:
--- Quote from: tooki on November 07, 2019, 12:21:25 pm ---Another weird little thing I just thought about: US customary mostly uses inches divided fractionally in powers of 2. In a way, works really well because it’s easy to shift how much granularity you need without necessarily adding tons of digits. But then in electronics, the normal spacing has been 0.1”, which doesn’t align with the powers-of-2 fractions. That’s just as annoying as making 0.1” spacing play nice with metric! :p --- End quote --- 0.1 is short for 1/10. 0.10347109387410387 is short for 10347109387410387/100000000000000000. So the notation is already simplified, and powers of 10 are more convenient, because 10 is the base we already use for numbers greater than 1 and it accomodates more numbers in each position, without having to change the power. For instance, with powers of two, you have: 1/16 1/8 3/16 1/4 5/16 3/8 7/16 1/2 9/16 5/8 11/16 3/4 13/16 7/8 15/16 1 See that de denominator changed from 1 to 2, to 4, to 8 to 16 so we could have 16 counts. Now: 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 The denominator didn't change for 10 counts, and when it does, it will be a power of 10. This means that you can use the same unit to measure very big to very small numbers, for instance, the size of the sun, the size of your house or the size of a proton. |
| Tepe:
--- Quote from: bsfeechannel on November 08, 2019, 09:02:10 pm ---For instance, with powers of two, you have: 1/16 1/8 3/16 1/4 5/16 3/8 7/16 1/2 9/16 5/8 11/16 3/4 13/16 7/8 15/16 1 See that de denominator changed from 1 to 2, to 4, to 8 to 16 so we could have 16 counts. Now: 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 The denominator didn't change for 10 counts, and when it does, it will be a power of 10. This means that you can use the same unit to measure very big to very small numbers, for instance, the size of the sun, the size of your house or the size of a proton. --- End quote --- There similarity would be more easy to see if the fractions weren't reduced: 1/16 2/16 3/16 ... 15/16 1 1/10 2/10 3/10 ... 9/10 1 Hexadecimal versus decimal: 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.A 0.B 0.C 0.D 0.E 0.F 1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Tomato, tomahto. The real "problem" is twofold: 1. Imperial changes base. Sometimes it's base 8, or base 16, or 32, or 64 depending on your needs. Then it's suddenly base 12 and what have you. That's not very systematic. 2. Our number system uses base 10. |
| tooki:
--- Quote from: bsfeechannel on November 08, 2019, 09:02:10 pm --- --- Quote from: tooki on November 07, 2019, 12:21:25 pm ---Another weird little thing I just thought about: US customary mostly uses inches divided fractionally in powers of 2. In a way, works really well because it’s easy to shift how much granularity you need without necessarily adding tons of digits. But then in electronics, the normal spacing has been 0.1”, which doesn’t align with the powers-of-2 fractions. That’s just as annoying as making 0.1” spacing play nice with metric! :p --- End quote --- 0.1 is short for 1/10. 0.10347109387410387 is short for 10347109387410387/100000000000000000. So the notation is already simplified, and powers of 10 are more convenient, because 10 is the base we already use for numbers greater than 1 and it accomodates more numbers in each position, without having to change the power. For instance, with powers of two, you have: 1/16 1/8 3/16 1/4 5/16 3/8 7/16 1/2 9/16 5/8 11/16 3/4 13/16 7/8 15/16 1 See that de denominator changed from 1 to 2, to 4, to 8 to 16 so we could have 16 counts. Now: 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 The denominator didn't change for 10 counts, and when it does, it will be a power of 10. This means that you can use the same unit to measure very big to very small numbers, for instance, the size of the sun, the size of your house or the size of a proton. --- End quote --- :::whoosh::: ^^^ sound of my point going right over your head. ;) --- Quote from: bsfeechannel on November 08, 2019, 07:45:49 pm --- --- Quote from: Altair8800 on November 08, 2019, 10:56:42 am ---Case in point, doing serious calculating Science/Engineering problems in US Customary Units is unnecessary hard (due to all the conversions you have to do and often you have to look up the conversion factors to be double certain) and as a result you have more greater chance of making errors (than working in Metric/MKS/SI). I recall getting one question wrong because I had to convert from PSI to lbf/ft^2. I think after that I started to convert all US Customary Units immediately to Metric MKS (Metre, Kilogram, Second). Do the maths, then I know I was guaranteed a MSK final result (like Pa/Pascal, N/Newton, J/Joule, W/Watt, etc.) then use the conversion tables to convert what ever the question asked. Sometimes at the end when I convert my metric result back to US Customary Units I might get some result like 4.99948, which I would just round to 5.000. A small few of my professors were not pleased me doing calculations this way, but couldn't complain to much because I got the correct result in the end... I view doing serious calculations in US Customary Units vs in Metric like doing calculations by hand vs using a calculator. Yes it can be done, but it is more time and more chance of error. And it sucks when you know there is a better way... Thanks again... :) --- End quote --- This is something some guys can't understand. The customary system has several units to measure essentially the same thing, using different number bases. So it's not enough to base those units on the SI and claim that metrication is done. One of the aims of the metric system is to reduce conversions to a minimum, so reducing the chance of error and its propagation. It's a well thought out system that integrates science, engineering, technology and everyday usage in a single standard, reflecting the times we are living. --- End quote --- Oddly enough, the fact that different number bases are used also acts as a kind of sanity check. In metric, it’s quite easy to make mistakes with how many decimal points you need to move the mantissa around. With non-10 bases, the mantissa changes as well, so if you suddenly see that it’s the same, you know you missed something. I say that after literally decades of using both systems side by side. (One issue I take with Customary critics is that they criticize a system they’ve never really used, so their smugness is based on theories, not practical experience.) --- Quote from: bsfeechannel on November 08, 2019, 07:45:49 pm ---Imperial is a cobbled up system of traditional units that looks and smells like a bygone era. --- End quote --- Well, it is an organically evolved system. But in many cases, those old units made sense in isolation. And regardless, there’s often no advantage to changing, but real costs and risks, so you just don’t until the balance of pros and cons changes. Anyhow, make sure you’re not going all rstofer again. ;) |
| Zero999:
--- Quote from: Tepe on November 08, 2019, 09:34:54 pm --- --- Quote from: bsfeechannel on November 08, 2019, 09:02:10 pm ---For instance, with powers of two, you have: 1/16 1/8 3/16 1/4 5/16 3/8 7/16 1/2 9/16 5/8 11/16 3/4 13/16 7/8 15/16 1 See that de denominator changed from 1 to 2, to 4, to 8 to 16 so we could have 16 counts. Now: 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 The denominator didn't change for 10 counts, and when it does, it will be a power of 10. This means that you can use the same unit to measure very big to very small numbers, for instance, the size of the sun, the size of your house or the size of a proton. --- End quote --- There similarity would be more easy to see if the fractions weren't reduced: 1/16 2/16 3/16 ... 15/16 1 1/10 2/10 3/10 ... 9/10 1 Hexadecimal versus decimal: 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.A 0.B 0.C 0.D 0.E 0.F 1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Tomato, tomahto. The real "problem" is twofold: 1. Imperial changes base. Sometimes it's base 8, or base 16, or 32, or 64 depending on your needs. Then it's suddenly base 12 and what have you. That's not very systematic. 2. Our number system uses base 10. --- End quote --- There's a reason why we use base 10: humans have ten fingers and it makes it easier for children to learn to count. In many respects, base 6 or 12 would be better, but base 10 is more intuitive. Yes, imperial and customary are a nightmare, because they use different bases, even within the same scale: 12 inches in a foot, 3 feet in a yard and 1790 1760 yards in a mile. |
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