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- Betelgeuse
- Beeblebrox_237
Metric vs Imperial
- Thread starter kikie
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- Inland Empire SoCal
- SOLID_LIFTERS
"Most Knowledgeable?" Pfffttt...
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- marluxiaXI11
Famine is always correct. There are now 24 hours in a week.
- 28,470
- Windsor, Ontario, Canada
- Johnnypenso
I was taught in high school that the entire system was based on:
A metre is the distance from one of the poles to the equator/10,000,000
..which doesn't seem arbitrary to me.
From that:
1cm=1/100 metre
1cm cubed of water is 1 gram
1kg is a cube of water 10cm squared or 1000 cu. cm.
Seems pretty simple to me...everything is a multiple of 10/100/1000 etc. and mass, volume and distance are all easily calculated and easily related to one another.
- 87,564
- Rule 12
- GTP_Famine
That's how long I'm awake 
Try explaining to aliens that our base unit of time, the one we use to base pretty much the entire metric system on, is one sixtieth of one sixtieth of one twentyfourth of one threehundredandsixtyfivepointtwofivegiveortaketheoddleaponeofthemth of the time it takes our planet to go around our host star and watch them blink - probably sideways - in disbelief. Then say that we've redefined it as 9,192,631,770 oscillations of a Caesium-133 atom because we found Cs-133 was very reliable and wait for them to say "I thought your whole measuring system was base10?".
The metric system is no better for universal communication than the Imperial (or avoirdupois) system is.
You're going to have to explain to aliens that the entire measuring system is based on that. When the flaw's pointed out, you can fall back on the distance light travels in one 299,792,458th of a second (let's assume you've got over the second hurdle above), then try to tell them why you picked that number and how that's somehow the most regular one you could come up with.
The raw definitions of the SI base units of metres, kilograms and moles aren't based on a 10/100/1000 multiple of anything, but on the properties of arbitrarily chosen items (light over an arbitrary time, water, septillions of atoms). The second - which isn't metric and forms the basis of several other SI base units - is based on the properties of an arbitrarily chosen item (the regularity of Caesium atom oscillation). The Kelvin is based on a scale that's based on the properties of an arbitrarily chosen item (water)...
And, as previously discussed with GT Ace, not everything is a multiple of 10/100/1000 anyway. We still have to divide circles up into sixties and time up into a mix of sevens, nearly-thirties and multiples of six. We stick with this simply because we're used to it. On this basis, we can't denigrate USians for sticking to avoirdupois simply because they're used to it.
Only in the world though.
Try explaining to aliens that our base unit of time, the one we use to base pretty much the entire metric system on, is one sixtieth of one sixtieth of one twentyfourth of one threehundredandsixtyfivepointtwofivegiveortaketheoddleaponeofthemth of the time it takes our planet to go around our host star and watch them blink - probably sideways - in disbelief. Then say that we've redefined it as 9,192,631,770 oscillations of a Caesium-133 atom because we found Cs-133 was very reliable and wait for them to say "I thought your whole measuring system was base10?".
The metric system is no better for universal communication than the Imperial (or avoirdupois) system is.
It doesn't seem arbitrary to base a fundamental measurement on an arbitrary subdivision of an (incorrect) estimate of an arbitrary measurement on an arbitrary planetary body?
You're going to have to explain to aliens that the entire measuring system is based on that. When the flaw's pointed out, you can fall back on the distance light travels in one 299,792,458th of a second (let's assume you've got over the second hurdle above), then try to tell them why you picked that number and how that's somehow the most regular one you could come up with.
Why water? Arbitrary - and wrong the instant you move up orders of magnitude, because the kilogram (which is the base unit) is defined as 1.000025 litres (arbitrary) of water (arbitrary) at 4 degrees Celsius (arbitrary). One tonne (which should be one megagram if we're being all regular like) is 1000.025 litres - or rather 1.000025 cubic metres since litres aren't regular either.
Until you reach the very small - or very large - numbers that define them and it all breaks down.
The raw definitions of the SI base units of metres, kilograms and moles aren't based on a 10/100/1000 multiple of anything, but on the properties of arbitrarily chosen items (light over an arbitrary time, water, septillions of atoms). The second - which isn't metric and forms the basis of several other SI base units - is based on the properties of an arbitrarily chosen item (the regularity of Caesium atom oscillation). The Kelvin is based on a scale that's based on the properties of an arbitrarily chosen item (water)...
And, as previously discussed with GT Ace, not everything is a multiple of 10/100/1000 anyway. We still have to divide circles up into sixties and time up into a mix of sevens, nearly-thirties and multiples of six. We stick with this simply because we're used to it. On this basis, we can't denigrate USians for sticking to avoirdupois simply because they're used to it.
Aliens
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- 151
- NRW
One thing that interests me. Let´s say you have to produce one part that should be 16mm wide with a tolerance of .3 of a mm. How would you say that in imperial units?
- 151
- NRW
Okay thanks, that was the point. I didn´t know if there is a smaller unit than inches, or if you have to use broken numbers.
BobK
Premium
- 7,020
- Massachusetts, USA
When the metric system was first devised, a meter was defined as one ten-millionth of the distance from the North Pole to the equator on a line through Paris (since it was devised by the French) They sent out a surveying party to determine this distance as accurately as possible. The gram was then established as the mass of one cubic centimeter of water at 4 degrees centigrade. Why water? Because it's easily available. Why 4 degrees C? Because that's when its density is highest. So originally the mass of one kilogram was established as exactly 1000 cubic centimeters of water; however as it turned out they were off a bit on their measurement of the length of a meter. In any case the mass of a kilogram ended up being that of 1000.025 cubic centimeters even though the original intention was that it should be exactly 1000.
They also proposed a metric version of time, in which a day would be divided into 10 "hours" (I don't know the actual proposed term), subdivided into 100 "minutes" which would then be subdivided into 100 "seconds". So the "metric minute" would be slightly longer than our standard minute, 1000 per day vs 1440, and the "metric second" would be shorter than our standard second (100,000 per day vs 86,400). This proposal never caught on however.
For subdivisions of a circle I have come across the "gradian" which is 1/400th of a circle. I've never seen grads in actual use, though; the only place I've ever encountered them is a "grads" button on scientific calculators next to the degrees and radians buttons.
Personally I was brought up with the so-called "standard system" of measurement with my first hands-on exposure to the metric system in high school science classes. I've since learned to work with metric measurements, even though I still tend to think in terms of standard units as well as memorizing a few handy conversions, such as 40 inches (equals 3 ft 4 in) to the meter being generally close enough, 2 1/2 cm to the inch, 427 cubic inches is 7 liters, a 5 liter engine is a 307, etc.
Fun fact: one mile per hour is 2688 furlongs per fortnight.
They also proposed a metric version of time, in which a day would be divided into 10 "hours" (I don't know the actual proposed term), subdivided into 100 "minutes" which would then be subdivided into 100 "seconds". So the "metric minute" would be slightly longer than our standard minute, 1000 per day vs 1440, and the "metric second" would be shorter than our standard second (100,000 per day vs 86,400). This proposal never caught on however.
For subdivisions of a circle I have come across the "gradian" which is 1/400th of a circle. I've never seen grads in actual use, though; the only place I've ever encountered them is a "grads" button on scientific calculators next to the degrees and radians buttons.
Personally I was brought up with the so-called "standard system" of measurement with my first hands-on exposure to the metric system in high school science classes. I've since learned to work with metric measurements, even though I still tend to think in terms of standard units as well as memorizing a few handy conversions, such as 40 inches (equals 3 ft 4 in) to the meter being generally close enough, 2 1/2 cm to the inch, 427 cubic inches is 7 liters, a 5 liter engine is a 307, etc.
Fun fact: one mile per hour is 2688 furlongs per fortnight.
- 87,564
- Rule 12
- GTP_Famine
The distance is actually 10,001,965m - any quadrant on a meridian is, Paris or otherwise.
And it's an arbitrary division of an arbitrarily chosen location.
Highly purified water is not easily available - seawater is, but it's not of an appropriate density to fill the volume with the right mass due to the impurities. And of course it's only pure water that's densest at 4 degrees - seawater isn't
The metric system is nice and regular and all (save for the bits it can't be), but it's not of universal usefulness because it relies on arbitrarily chosen definitions - bits of planet, random substances, very irregular subdivisions of natural occurrences to fit in with our previous determinations - that make very little external sense...
And even then they only make sense in base 10 - which we've chosen because that's how many fingers we have and we only have that many because our evolutionary path included the pentadactyl limb... But at least we can explain that to an alien with our hands (assuming no amputees show up).
The issue was probably that it'd require redefining all mathematics that underpins the sciences. We're kind stuck on a second being as long as it is because it's too tough to change.
Of course days are effectively as arbitrary - it's about how long this one rock takes to spin once (give or take a few seconds). Years too.
Indeed - and radians too, at a pith of a circle (a radian is an arc [length of circumference] equal to the circle's radius).
I like Imperial, US Imperial and metric. They're all based on very oddly chosen things that have significance to our bodies or planet - one isn't better than another because it forgets this and goes in tens, nor is it worse because you can't cut things into threes all that easily.
But a proper universal measuring system should be based in fundamental dimensions - like the Planck length and time, the speed of light in a vacuum and the Gravitational Constant.
Danoff
Premium
- 34,039
- Mile High City
When was the last time you bought coca cola by the gallon? Which does your meter read kWh or BTU?
That's how long I'm awake
Try explaining to aliens that our base unit of time, the one we use to base pretty much the entire metric system on, is one sixtieth of one sixtieth of one twentyfourth of one threehundredandsixtyfivepointtwofivegiveortaketheoddleaponeofthemth of the time it takes our planet to go around our host star and watch them blink - probably sideways - in disbelief. Then say that we've redefined it as 9,192,631,770 oscillations of a Caesium-133 atom because we found Cs-133 was very reliable and wait for them to say "I thought your whole measuring system was base10?".
The metric system is no better for universal communication than the Imperial (or avoirdupois) system is.It doesn't seem arbitrary to base a fundamental measurement on an arbitrary subdivision of an (incorrect) estimate of an arbitrary measurement on an arbitrary planetary body?
You're going to have to explain to aliens that the entire measuring system is based on that. When the flaw's pointed out, you can fall back on the distance light travels in one 299,792,458th of a second (let's assume you've got over the second hurdle above), then try to tell them why you picked that number and how that's somehow the most regular one you could come up with.Why water? Arbitrary - and wrong the instant you move up orders of magnitude, because the kilogram (which is the base unit) is defined as 1.000025 litres (arbitrary) of water (arbitrary) at 4 degrees Celsius (arbitrary). One tonne (which should be one megagram if we're being all regular like) is 1000.025 litres - or rather 1.000025 cubic metres since litres aren't regular either.Until you reach the very small - or very large - numbers that define them and it all breaks down.
The raw definitions of the SI base units of metres, kilograms and moles aren't based on a 10/100/1000 multiple of anything, but on the properties of arbitrarily chosen items (light over an arbitrary time, water, septillions of atoms). The second - which isn't metric and forms the basis of several other SI base units - is based on the properties of an arbitrarily chosen item (the regularity of Caesium atom oscillation). The Kelvin is based on a scale that's based on the properties of an arbitrarily chosen item (water)...
And, as previously discussed with GT Ace, not everything is a multiple of 10/100/1000 anyway. We still have to divide circles up into sixties and time up into a mix of sevens, nearly-thirties and multiples of six. We stick with this simply because we're used to it. On this basis, we can't denigrate USians for sticking to avoirdupois simply because they're used to it.
You're only pointing out the need to clean up the time and angle system to something more readily calculable. Radians actually work quite well. Nobody uses centi-radians, but it would work well for a degree-sized unit.
The distance is actually 10,001,965m - any quadrant on a meridian is, Paris or otherwise.
And it's an arbitrary division of an arbitrarily chosen location.Highly purified water is not easily available - seawater is, but it's not of an appropriate density to fill the volume with the right mass due to the impurities. And of course it's only pure water that's densest at 4 degrees - seawater isn't
The metric system is nice and regular and all (save for the bits it can't be), but it's not of universal usefulness because it relies on arbitrarily chosen definitions - bits of planet, random substances, very irregular subdivisions of natural occurrences to fit in with our previous determinations - that make very little external sense...
And even then they only make sense in base 10 - which we've chosen because that's how many fingers we have and we only have that many because our evolutionary path included the pentadactyl limb... But at least we can explain that to an alien with our hands (assuming no amputees show up).The issue was probably that it'd require redefining all mathematics that underpins the sciences. We're kind stuck on a second being as long as it is because it's too tough to change.
Of course days are effectively as arbitrary - it's about how long this one rock takes to spin once (give or take a few seconds). Years too.Indeed - and radians too, at a pith of a circle (a radian is an arc [length of circumference] equal to the circle's radius).
I like Imperial, US Imperial and metric. They're all based on very oddly chosen things that have significance to our bodies or planet - one isn't better than another because it forgets this and goes in tens, nor is it worse because you can't cut things into threes all that easily.
But a proper universal measuring system should be based in fundamental dimensions - like the Planck length and time, the speed of light in a vacuum and the Gravitational Constant.
From there it needs to go in base something rather than arbitrary conversion values. AU, days, weeks, months, years all need revising. They're fairly terrible systems as anyone who has attempted to use them in scientific calculations immediately concludes (which is no doubt why you're bringing it up).
I'd be in favor of basing time off of the length of a day (I know that's not constant). Seconds being something like 100,000th of a day, and hours being 1000 seconds. You'd end up with 100 hours in the day, which would make an hour more like a 15 minutes are now (which is fine because that's the resolution to which people generally schedule things anyway).
Our unit system doesn't have to be easily explainable to aliens - it just needs to make sense and be easy to use to us humans.
The absolute worst part about english units is pound force vs pound mass (not to be confused with pound currency). Let's not re-use the same word for everything, it's confusing at the least, and dangerous at the worst.
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- Murica
- BasedAckbar
I like Imperial for height and distance measurement, metric for weight.
Danoff
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- Mile High City
Imperial is terrible for height (ie: distance). You're traveling at 10 miles per second. Quick, how many inches per second is that? You're traveling at 10 km per second, how many mm per second is that? Easy.
Spacecraft velocity is measured in km/s and regularly gets tweaked by mm/s.
- 9,058
- Murica
- BasedAckbar
But I don't do that while I'm driving. I see a board saying town 80 miles away, and I'm doing 70 I know I'm going drive for another hour and some change. If I'm in NASA, then yeah I''ll do the metric conversions, but I hope my car won't make me.
And Imperial works for height for me because I'm used to it. I can easily picture someone being 6 feet instead of 2 meters.
And Imperial works for height for me because I'm used to it. I can easily picture someone being 6 feet instead of 2 meters.
Danoff
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Terrible reason for just about anything.
I'm an engineer in England, and both metric and imperial are used a lot, almost 50-50 in some situations.
Having been on an old manual lathe for a while, everything is in imperial, from the collets that material is held in to the measurements on all of the handles, but to comply to british standards and to communicate with customers ordering parts, we have to use metric. It's annoying converting it all the time, for example 5/8ths of an inch converts to 15.875mm, but because the machines are built to last and they still put out a good job when used properly, I don't think we'll ever get rid of them.
Most of the time i'm on a modern CNC lathe though, and everything on it is metric. Metric is the way the industry is going, but because we can still string out the old equipment we will always have imperial.
Having been on an old manual lathe for a while, everything is in imperial, from the collets that material is held in to the measurements on all of the handles, but to comply to british standards and to communicate with customers ordering parts, we have to use metric. It's annoying converting it all the time, for example 5/8ths of an inch converts to 15.875mm, but because the machines are built to last and they still put out a good job when used properly, I don't think we'll ever get rid of them.
Most of the time i'm on a modern CNC lathe though, and everything on it is metric. Metric is the way the industry is going, but because we can still string out the old equipment we will always have imperial.
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