Being something of a discussion on measurement units
"There are countries with the metric system, and there's the country that landed on the moon first."
— seen on Reddit
Oh, I get it. You grew up in the USA with feet and inches. You maybe use them at work if you're a carpenter or builder. Your thermometer reads in Fahrenheit, your clock only shows twelve hours, and then "AM" or "PM". Fields are measured in acres, not hectares. You cook? You read recipes that measure things in cups, not grams (or even ounces). "A pint's a pound the world around", petrol goes into your car in gallons and by all that's holy you get miles to those gallons. "The internet was invented in America and we all use operating systems made in America on computers designed there." You may be a motor mechanic ticked off at having to have two sets of spanners, or whatever. "Communists use metric", I understand all that. But honestly, there's no need to hate so much on the metric system. If you're one of those who agrees with the quotation mentioned above, who thinks that America is right and the rest of the world is wrong, this is for you.
Before I begin, a disclaimer. I too grew up with all those things in England. Inches, feet, yards, furlongs, all that stuff. I knew what a pint was (I mean we sort of invented it). I've already written about why the American pint is smaller than the UK's and why that's okay, and also why you spell some things differently. I agree that Fahrenheit can seem more sensible for describing outdoor temperatures. Whilst I can understand where you're coming from, I disagree over the way you're going. Let's talk about it.
Space, and the fog of war
Firstly, let's get that quotation out of the way. I can't disagree that you landed lots of people on the moon (so far you're the only country to do so). But the Apollo Guidance system was developed and programmed using SI Units¹ (although outputs were in American Standard units), and during landing, the astronauts called out altitudes and distances in feet. NASA designers and engineers were encouraged to use metric measurements, though it has to be said that one of the more expensive losses in space, the Mars Climate Orbiter failed due to a cockup translating units (looking at you, Lockheed Martin²).
"The root cause was found to be the use of English units for thruster performance data generated by a ground based computer program. This data was used in the construction of trajectory models for the spacecraft, and the modellers assumed the data was in metric units as per the specifications."
By this time (in fact since 1959) the yard had been defined internationally as being exactly 0.9144 metres and NASA did use that conversion. Yes, you heard that right. You see the yard (and pound and gallon!) used to be based on a physical standard yardstick. Long story, but there have been a few of them, lengths of metal that were kept to be used as reference points. One of the yardsticks was destroyed in a fire in 1834. A commission was created to recreate the lost standards, and in 1838 a new yardstick (and a new troy pound) was created , exact copies of which were sent around the whiole world. The one sent to the USA was known as "Bronze Yard No. 11", but the yard is now defined in terms of the SI system (hence, based on the metre). So you're still effectively using metric measures, just as NASA was using metric measures (and mistakes were still made!).
Let's talk about the military now. If you were ever in the US military you're doubtless familiar with "klicks"³ as a measurement of distance, a klick being about two-thirds of a mile when you're yomping). This has been used since at least Vietnam (not that I was there but I watched a lot of films about it), popular because of the involvement of the militaries from Australia and New Zealand. What is a klick? It's a kilometre. NATO had standardised on kilometres on all maps years earlier.
On to rifle calibres. What are the common references used by all NATO forces? 7.62mm (a calibre developed in the US) and 5.56mm. The former is almost identical to the .308 Winchester (though it's not recommended to use 7.62mm ammunition in rifles designed for civilian use). The latter round is equivalent to the .223 Remington and from my own experience, can be used in (for example) the Ruger Mini-14 rifle. It's not just rifles, either. What's the most popular handgun ammo used in the US? Almost certainly it's 9mm. Nine. Millimetres. So you see, metric is everywhere and you're using it, and America has been using it, for decades⁴. In space and on the battlefield.
I spent most of my life living in countries (Germany and the UK_ that used the metric system, I'm familiar from childhood with Imperial and grew to understand the metric system. I can squint at a few metric measures and figure out a conversion in my head. A kilogram is about 2.2 pounds. An ounce is about 28 grams (30 if I'm rounding), a metre is about 3.3 feet and a centimetre about ⅖ inch. Longer distance? We've covered the kilometre (roughly ⅔ or .66 mile). A US Standard gallon is about 3.75 litres, so a litre is about 4.25 cups. If you're talking Imperial pints, "a litre of water's a pint and three-quarters". The 24-hour clock ("military time" in the US) is easy. If the numbers are bigger than 1200, it's after noon. If it's bigger than 1300, subtract 1200 and there ya go. Easy.
Temperatures are more complex, I have to admit. The scientific standard is degrees kelvin and it uses Celsius units. Fahrenheit I had to relearn when I came to the US nineteen years ago (a quarter of my life!). Nowadays if I read "30°C" I have to run to an online conversion. I'll grant you this one personally, but even so…
So to those Americans pissed off at the rest of the world over measurements, you are kinda behind the times. There's a reason the rest of the world standardised, because it makes sense to work with other countries using agreed standards. Feet and inches may be fine on the building site, but for manufacturing, science and global commerce, you have to adapt. We've all had to adapt. On the 15th of February 1971 ("Decimal Day") the UK formally adopted a decimal currency system, moving from twelve pennies in a shilling and twenty shillings in a Pound Sterling, to a much simpler 100 pennies to the pound. There had been grumbling for years about it, but in the finish, it was all worthwhile. Imagine how you'd feel visiting the UK and having to deal with three different number bases. I bet you're happy we changed.
Now remember that Mars mission. You can still be proud of your country, just in metric.
nicolasstag says oh dude, don't even get me started. I've been saying for YEARS that we should switch over to Kelvins. I greatly desire a weather app on my phone that displays the temperature in kelvins alongside f/c. I tried them all, dozens of weather apps. No kelvins, not any one of them. It's brutal.
Iron node 5
¹ Apollo
² https://www.simscale.com/blog/nasa-mars-climate-orbiter-metric/
³ "Klick"
⁴ NATO standards
$ xclip -o | wc -w
1177