Also sorry to be that guy but:
> when people specify a temperature in "degrees" when it’s not clear from the context which scale is being used.
It should be degrees Celsius. Anything else is just insane ;)
I'm not saying it makes a ton of sense, but my only real defense of it.
That said, I find negative units rather silly in most measurements, so we should really be using K I think.
That's your choice though. Outside temperature cannot be measured precisely enough to warrant decimals (it's supposed to be 17.4°C outside but who can tell the difference with 17°C or 18°C...) but my car's A/C is set to 21.5°C and my home's heating is set to 19.5°C.
Ovens aren't accurate enough for measuring 5°C, let alone 2.5°C.
(Ignoring badly-translated American recipes which call for 179°C and 454.5g of potatoes.)
For air temperature, my behaviour wouldn't change at all if someone told me it is 18±0.25°C rather than the normal 18±0.5°C. We could round to the nearest 2° and it would be fine.
> badly-translated American recipes which call for 179°C and 454.5g of potatoes
This drives me up the wall .. but a lot of UK goods are sold in "metric-numbered imperial sizes". At the weekend I bought 450g (half lb) of meat and a 6.3mm (1/4") router bit.
Measuring body temperature with precision of 0.1°C is very common. In fact, I never saw an integer in this context.
Measuring by weight is the one cooking-related hill that I will die on.
(Recently, I had a recipe ask for four cups of lettuce, which could've been anything from 0.5x to 4x of what I finally went with, depending on how much I packed the cups. It's lunacy)
No argument from me about Celsius, but even on this site there are people who think otherwise.
Celsius is obviously more useful in a scientific context, but 99% of the time when I'm talking about the temperature, I'm not doing a scientific experiment, I'm asking "how hot/cold is it outside?" In that context I actually find Fahrenheit to be a more intuitively useful scale once you get used to it.
Celsius crams the entire range of likely outdoor temperatures into a narrow range with awkwardly-sized units that don't provide enough information. If someone tells me it's 15C outside, how many layers do I need to wear? I still don't have a good feel for it from the number alone, even after spending most of my life in countries where Celsius is the norm.
But in Fahrenheit, things make more obvious sense. 0 F means "insufferably cold", 100 F means "insufferably hot", and to get a meaningful idea of what the weather feels like on my skin, I just need the range: it's "in in fifties" or "in the seventies" etc.. It takes some getting used to, but I actually quite like it. Thanks, America!
(I'd also make a similar argument that feet and inches are a much more intuitively meaningful scale than centimetres for measuring human height. But that might be my British bias.)
It begins with something like "I decided to create the perfect scale for measuring the temperature outside for the weather. Of temperatures taken where people live, I will scale the 95th percentile of high temperatures as 100 and the 95th of cold temperatures as 0."
The goal of which was, if a temperature is <0 it's really cold, and a temperature >100 is really hot.
My memory is that using this method the scale was within 2 degrees of Fahrenheit! Of course, I've never found the story again so who knows the details of their method or if I'm even remembering correctly.
Erm, they didn't invent it. Most (all?) American units were inherited from British. Farenheit was invented in Europe.
I have also warmed to Imperial/American units for certain things. A lot of simple recipes are easier to remember in ounces than in grams. For example, 5 ounces of flour and 4 ounces of butter gives you enough shortcrust pastry for a 9 inch tin. Inches seem about the right size, but centimeters are too small. People's heights tend to fall around 5-6 feet which is nice, or 150-180/1.5-1.8 which is kind of awkward. Basically, imperial measurements seem much more "human" while metric seems based on arbitrary universal constants like the speed of light which have absolutely no bearing on our lives.
None of this means that "cups" are a sane way to measure ingredients for cooking, though. There's just so many reasons why it's bad but even just from a laziness point of view it's an extra thing to wash up.
Um, No. Metric is based on the size of the Earth and the density of water.
The original definition of the meter was "one ten-millionth of the distance from the pole to the equator", making the circumference of the Earth 40,000 km or 40 Mm. The kilogram was originally defined as the mass of one litre of water. (1 m³ = 1000 kg). It wasn't arbitrary.
Basing a unit of measurement on the size of the Earth? Why not base it on the size of the Sun, or on the distance between Toronto and Timbuktu, or on the combined height of every member of the U.S congress if they all laid head to toe? Those numbers mean nothing to me, but I have a good intuitive feel for distances like "the general range of human heights", "the size of my foot", or "how far I can walk in an hour". Imperial measurements have their origins in those kind of intuitive, everyday quantities that we humans have a natural feel for; that's the sense in which they're not "arbitrary".
That doesn't nmake imperial measurements unconditionally "better", it just makes them more useful and relatable in certain contexts.
I also find inches, feet, miles etc. more intuitive than meters for basically everything. "so-and-so meters" or "such-and-such kilometers" doesn't describe anything to me, give it to me in inches/feet/miles so I can visualize the damn thing.
Moral I suppose is that metric is great for describing the universe, but the problem is we're dumb apes.