# The USA and the Metric System. **URL:** \ **Category:** Great Debates\ **Created:** [November 17, 2018, 9:15am UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672 "2018-11-17T09:15:26Z")\ **Posts on this page:** 20\ **Page:** 6
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [November 20, 2018, 6:48pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/101 "2018-11-20T18:48:36Z")
> [@Bullitt](#): > > 0°C for water’s freezing point, and 100°C for its boiling point. What’s not to like? How often do you really need that? You can’t remember 32 and 212? F- 100 Human body. 0 really fucking cold. Under F, temps going negative are rare in most populated areas. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [November 20, 2018, 8:07pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/102 "2018-11-20T20:07:27Z")
> [@DrDeth](#): > > 0 really fucking cold. > > Under F, temps going negative are rare in most populated areas. For varying definitions of populated. I regularly encounter temps below 0, in the last year I’ve been down to -30F at least once, -20F many times. I’ve also been in 110F at least once this past year. ---
**Author:** ![toastie](https://avatars.discourse-cdn.com/v4/letter/t/3be4f8/32.png) [@toastie](https://boards.straightdope.com/u/toastie)\ **Post date:** [November 20, 2018, 8:18pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/103 "2018-11-20T20:18:36Z")
> [@BrickBat](#): > > For sure! I’d vote the 13mm as a close second though. Given that I lost both the 13 and the 10 when I was replacing the dead battery in my car, I think they go in pairs. They are hard to hold onto when the temperature is 5 degrees F. And since we’re talking metric here, that’s -15 C. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [November 20, 2018, 8:34pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/104 "2018-11-20T20:34:23Z")
> [@Hermitian](#): > > That is because those states were dropped on their heads as babies. Consecutive exit numbers provide no value whatsoever. Exit numbers by mile marker is the only rational way to do it. I don’t think it’s a big deal either way (much like metric much of the time), but I was going to offer California as an example but I guess I’m mistaken. There are at least 3 systems: sequential (9 states+DC, mostly the northeast), mile marker throughout the length of that highway within the state, and mile marker within each county (CA). ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [November 20, 2018, 9:22pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/105 "2018-11-20T21:22:07Z")
> [@DrDeth](#): > > … > Under F, temps going negative are rare in most populated areas. Like Canada, Russia, China, Finland, Sweden, Denmark, Norway, Iceland… ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [November 20, 2018, 9:29pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/106 "2018-11-20T21:29:13Z")
I don’t think Denmark gets to negative F except in extreme exception times. Copenhagen’s average low in January is 30 F, record is 0 F. ---
**Author:** ![kenobi\_65](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kenobi_65/32/13178_2.png) [@kenobi\_65](https://boards.straightdope.com/u/kenobi_65)\ **Post date:** [November 20, 2018, 9:31pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/107 "2018-11-20T21:31:20Z")
> [@Leaffan](#): > > Like Canada, Russia, China, Finland, Sweden, Denmark, Norway, Iceland… Wisconsin, Minnesota… 😃 ---
**Author:** ![rat\_avatar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rat_avatar/32/255_2.png) [@rat\_avatar](https://boards.straightdope.com/u/rat_avatar)\ **Post date:** [November 20, 2018, 10:02pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/108 "2018-11-20T22:02:47Z")
Or Wyoming. The town I grew up in has an average annual low of 20.3°F or -6.5°C (Including summer!) The average low for last January, which was a warm year was -4°F or -20°C ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [November 20, 2018, 10:37pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/109 "2018-11-20T22:37:44Z")
You folks are ALL missing the big special advantage of the SI. This unit system is coherent. That is, the units having different dimensions fit with one another. Many of the basic laws of nature and engineering have no conversion factors in them. Crafter\_Man, you use SI units whenever you use the various relations on the Ohm’s Law wheel. Just imagine if every single one of those twelve equations had different factors in it, like volts X amps X 13.959 = watts. Those of us who work in the physical sciences not limited to electricity have to deal with insanity like that all the time. I once created a unit conversion table for heat transfer coefficient and came up with 215 different versions depending on which units were used, and all but one of them had numerical factors in it. I always, as a practical matter, have to convert things into SI to calculate a result, and then, if I need to for the sake of my “customer”, I convert that into other customary units. It’s not that the sizes of the units are necessarily better in some systems than others. Of course, you get used to whatever you use. It’s the interrelationships between units that make any coherent system, such as the SI, better. > **[Coherence (units of measurement)](https://en.wikipedia.org/wiki/Coherence_(units_of_measurement))** > > A coherent system of units is a system of units of measurement used to express physical quantities that are defined in such a way that the equations relating the numerical values expressed in the units of the system have exactly the same form, including numerical factors, as the corresponding equations directly relating the quantities. It is a system in which every quantity has a unique unit, or one that does not use conversion factors. > A coherent derived unit is a derived unit that, for a given... ---
**Author:** ![rat\_avatar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rat_avatar/32/255_2.png) [@rat\_avatar](https://boards.straightdope.com/u/rat_avatar)\ **Post date:** [November 20, 2018, 10:52pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/110 "2018-11-20T22:52:50Z")
> [@Napier](#): > > You folks are ALL missing the big special advantage of the SI. This unit system is coherent. That is, the units having different dimensions fit with one another. Many of the basic laws of nature and engineering have no conversion factors in them. Crafter\_Man, you use SI units whenever you use the various relations on the Ohm’s Law wheel. Just imagine if every single one of those twelve equations had different factors in it, like volts X amps X 13.959 = watts. Those of us who work in the physical sciences not limited to electricity have to deal with insanity like that all the time. I once created a unit conversion table for heat transfer coefficient and came up with 215 different versions depending on which units were used, and all but one of them had numerical factors in it. I always, as a practical matter, have to convert things into SI to calculate a result, and then, if I need to for the sake of my “customer”, I convert that into other customary units. > > It’s not that the sizes of the units are necessarily better in some systems than others. Of course, you get used to whatever you use. It’s the interrelationships between units that make any coherent system, such as the SI, better. > [Coherence (units of measurement) - Wikipedia](https://en.wikipedia.org/wiki/Coherence_(units_of_measurement)) I do find the idea of coherent units nice, but the reality is that most of the fields that would perhaps use them either use natural units or the [cgs units](https://en.wikipedia.org/wiki/Centimetre%E2%80%93gram%E2%80%93second_system_of_units). Fields like material science, electrodynamics and astronomy use a non-SI system because of tradition and because it make the math pretty. Which is the same reason engineers use really nasty systems like the British Engineering system. The SI system \*es the best option \*we have, but part of the reason adoption pretty much requires government mandate is that most users don’t really care about the elegance if it doesn’t really help them. The only real difference is that nobody debases CERN for not using SI is because it is hidden in the math. ---
**Author:** ![Declan](https://avatars.discourse-cdn.com/v4/letter/d/ecae2f/32.png) [@Declan](https://boards.straightdope.com/u/Declan)\ **Post date:** [November 20, 2018, 11:14pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/111 "2018-11-20T23:14:20Z")
> [@Balthisar](#): > > You weren’t American standard, though. For example, you had Imperial gallons instead of US gallons. We were American Standard enough to freak Trudeau out enough to switch , your point is valid but I do think had we stayed we would have moved liquids to American commonality. ---
**Author:** ![rat\_avatar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rat_avatar/32/255_2.png) [@rat\_avatar](https://boards.straightdope.com/u/rat_avatar)\ **Post date:** [November 20, 2018, 11:18pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/112 "2018-11-20T23:18:19Z")
Technically what was Canada was on the same standard as the US until 1824 the British created and adopted the imperial gallon. The US gallon is just the Queen Anne or _wine gallon_ adopted by the UK in 1707. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [November 20, 2018, 11:24pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/113 "2018-11-20T23:24:46Z")
> [@rat\_avatar](#): > > Technically what was Canada was on the same standard as the US until 1824 the British created and adopted the imperial gallon. > > The US gallon is just the Queen Anne or _wine gallon_ adopted by the UK in 1707. Interesting. If I’m reading correctly, it looks like the gallon was the base unit, and quarts, pints, cups, and fluid ounces are derived from that, hence the apparent rounding error in ounces? ---
**Author:** ![rat\_avatar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rat_avatar/32/255_2.png) [@rat\_avatar](https://boards.straightdope.com/u/rat_avatar)\ **Post date:** [November 20, 2018, 11:35pm UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/114 "2018-11-20T23:35:59Z")
The Old English (Queen Anne) Wine Gallon was standardized as 231 in[sup]3[/sup] which is exactly 133 fl oz. That size was like the current definition of all SI units, sized to match historical units of measure. Basically it was set to the common standard container size used in trade at the time as to make applying taxes easier. The Roman unciae is the origin of length (inch) , weight (ounce), and volume (fluid ounce) and was based on an older Byzantine fluid ounce. The imperial gallon _was_ based on the volume of 10 pounds of water at some specific temperature. ---
**Author:** ![RTFirefly](https://avatars.discourse-cdn.com/v4/letter/r/c77e96/32.png) [@RTFirefly](https://boards.straightdope.com/u/RTFirefly)\ **Post date:** [November 21, 2018, 12:22am UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/115 "2018-11-21T00:22:05Z")
> [@rat\_avatar](#): > > If you count with 12 with the segments of you of one hand, and use the other fingers of the other hand to track your place you end up with 60. This is where you can get the sumerian and babylonian mathematics base 60 that is in still used for seconds and degrees even today. Well sure, **you can invent** some bullshit way that segments of the fingers can be used to develop a given numerical system. Congratulations. And I can invent a way that the lifelines on the palms of your hands could do the same thing. So what? Doesn’t mean that’s where that numerical system came from. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [November 21, 2018, 12:56am UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/116 "2018-11-21T00:56:27Z")
> [@DrDeth](#): > > How often do you really need that? You can’t remember 32 and 212? > > F- 100 Human body. > 0 really fucking cold. > > Under F, temps going negative are rare in most populated areas. Wrong in every respect. First of all, “really fucking cold” is NOT an objectively rational basis for defining the baseline of a temperature scale. It’s more like a ridiculous basis, one that means nothing. Whereas 0°C, as has been repeatedly pointed out, is a very important point in everyday life and experience, and in driving safety. 100 does not represent normal human body temperature in any temperature scale. In Fahrenheit, it’s the rather odd number of 98.6, which incidentally in Celsuis is 37°C even, no decimal points. You don’t have to round up to the wrong value to eliminate the fractional degree. Not a big deal, but just saying. And finally, as also already pointed out, many populated areas do indeed dip below zero on the Fahrenheit scale in winter, at least occasionally. And when they hit zero Fahrenheit, it means nothing in particular, unlike the transition point of water at zero Celsius. I really don’t understand the hostility in the US to the world standard of measurement units. It’s an obstacle to commerce and a puzzlement to visitors from everywhere in the world except Liberia. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [November 21, 2018, 1:03am UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/117 "2018-11-21T01:03:52Z")
> [@rat\_avatar](#): > > The Old English (Queen Anne) Wine Gallon was standardized as 231 in[sup]3[/sup] which is exactly 133 fl oz. That size was like the current definition of all SI units, sized to match historical units of measure. Basically it was set to the common standard container size used in trade at the time as to make applying taxes easier. > > The Roman unciae is the origin of length (inch) , weight (ounce), and volume (fluid ounce) and was based on an older Byzantine fluid ounce. > > The imperial gallon _was_ based on the volume of 10 pounds of water at some specific temperature. Right, but it’s 128 US ounces, not 133. I am wondering whether the ounce differences between US and UK result from the gallon differences or was preexisting. > [@wolfpup](#): > > And finally, as also already pointed out, many populated areas do indeed dip below zero on the Fahrenheit scale in winter, at least occasionally. And when they hit zero Fahrenheit, it means nothing in particular, unlike the transition point of water at zero Celsius. No, it represents “the temperature of a solution of brine made from equal parts of ice, water and salt (ammonium chloride).” Which **is** granted a BS definition, as IIRC he came up with it post hoc. > [@](#): > > I really don’t understand the hostility in the US to the world standard of measurement units. It’s an obstacle to commerce and a puzzlement to visitors from everywhere in the world except Liberia. It seems people in the US care less than people outside of it. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [November 21, 2018, 2:10am UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/118 "2018-11-21T02:10:45Z")
> [@thelurkinghorror](#): > > No, it represents “the temperature of a solution of brine made from equal parts of ice, water and salt (ammonium chloride).” Which **is** granted a BS definition, as IIRC he came up with it post hoc. Sure, every standard has some kind of definition. My point is that it isn’t one that has any practical utility. > [@thelurkinghorror](#): > > It seems people in the US care less than people outside of it. That doesn’t address the question of outright _ **hostility** _ – the organized lobbying against the metric system, the shooting down of metric highway signs. It’s an interesting sociopolitical phenomenon. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [November 21, 2018, 3:19am UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/119 "2018-11-21T03:19:14Z")
> [@Leaffan](#): > > Like Canada, Russia, China, Finland, Sweden, Denmark, Norway, Iceland… Very few of the large cities in China normally get below 0 F, nor does Stockholm. Altho certainly some parts of many nations do get below 0F, few people live in areas where it normally does so. ---
**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\ **Post date:** [November 21, 2018, 5:44am UTC](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672/120 "2018-11-21T05:44:27Z")
> [@thelurkinghorror](#): > > I don’t think it’s a big deal either way (much like metric much of the time), but I was going to offer California as an example but I guess I’m mistaken. There are at least 3 systems: sequential (9 states+DC, mostly the northeast), mile marker throughout the length of that highway within the state, and mile marker within each county (CA). In many cities exits are closer together than 1 mile. You’d need to have exits 11.2 and 11.7 or a combination of mileage sequential like 11a and 11b. [Previous page](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672.md?page=5) [Next page](https://boards.straightdope.com/t/the-usa-and-the-metric-system/824672.md?page=7)