If I have 1.73 miles, I have to do the math to figure out how many feet that is, 1.73*5280~=9134, which is not something that's easy for me to do in my head.
However, 1.73 km is 1730 meters, which is way easier (at least for me, but that might be my bias).
Also, I haven't read GP's post, but I find Fahrenheit degrees easier to work with primarily because they're smaller; differences in temperature are easier to express in whole numbers.
Gallons, cups, tablespoons, quarts can go DIAF; I have to convert between these all the time, and it drives me batty!
Also all physics and engineering formula are designed to get and return metric values. When I see K = 0.5mv^2, I know v is supposed to be m/s and m is in kilograms and the result would be in Joules. If it's E = m*c^2, the same thing could be inferred about it.
I'm curios with all different units of measurement, how do you know when to use which. Is there a convention to always e.g. use ft/s or is it different in each formula?
E.g. in italy you refer to a glass of 200ml, 100 grams of pasta and two hectograms of parmigiano, while in hungary they routinely use deciliters and decagrams, which I'd never seen outside of school.
On the other hand I don't understand for examples why in the US they still use measures like "cup", "oz" "pint" in cooking. Should I buy a specifically sized "cup" to cook a us recipe? :)
By watching UK television it seems that even they are using kilograms, liters and also Celsius for oven temperature, and some weeks ago there was a UK famous baker talking with some US guest and saying almost the same thing.
disclaimer: I'm Italian
Thank goodness no one seems to use Pecks / Bushels / Dry Gallons (the dry volume versions of Pints / Quarts / Wet Gallons). The only time I ever hear of "Pecks" is in the Tongue Twister.
Not to mention, having everything in metric and by weight allows you to easily figure out ratios of ingredients, making scaling recipes much easier and quicker.
On "the line" where food is cooked, measurements are mainly by hand and by eye.
Yes, during service you're not busting out scales, and a lot of things aren't precisely measured. But anything where precision is necessary, you weigh it. Where it isn't, you don't.
Good luck ever finding a cup measure, or a measuring teaspoon in a professional kitchen though...
In which case, it matters little if you use metric or not...
Well, you still will measure things, most cooks will do a stint in the pastry kitchen, plus in the higher end restaurants a lot of pastry techniques transfer over to the savoury side (ie. a lot of what we think of as "molecular gastronomy").
While metric vs imperial doesn't matter for accuracy (whereas weight is more accurate than volume if you're measuring anything that's not liquid, and even with liquids it's easier to measure volume incorrectly), metric is just easier.
Historically: 1 Minute of Great Arc = 1 Nautical Mile
Great Arc = Earth circumference
1 Minute of Great Arc = Great Arc / (360 * 60)
Fun Fact:
Earth Circumference = 4 times great circle distance Pole to Equator historically defined as 10000km or 10 Million Meters (They were that serious about being decimal)
That also explains why the earth radius can still approximately be expressed as 10000km/(π/2) = 6366.2km (just 4.8km off the current mean radius defintion of 6371 km)
How often do you need to do this in reality? Most people in their day-to-day have no need to these conversions.
of course perception of a metric also plays a tremendous role here. I don't have a 'feel' for how long it is 12-feet for example but I can eye-ball a distance and tell how many meters it is pretty accurately. I guess this perception is the main issue that prevents imperial system to be abandoned in favor of SI - people are too much used to it.
I also hate the left driving lane of UK btw. It screws up with my head every time I rent a car in London...
stupid metric-ism ;)
This doesn't mean metric is more accurate over imperial, it just means that on a day-to-day, conversion is easier. Also, you can work out the relationship of units simply by their name.
deci = tenth, so decimeters means there is ten of them in one meter. deciliters means ten in one liter. so on and so forth. centi = hundred... milli = thousand...
etc.