XKCD: It's more than a comic

Celsius just isn't intuitive to me, yeah.

i 100% agree with "go metric but keep fahrenheit"

"It's 100 degrees" means boiling to me. The only advantage of Farenheit is that if your body temperature is too much above 100, then you have fever, and if it's too much below 100, you have hypothermia. For weather measurements, it's completely useless. 100 degrees is a really hot summer day, but by far not the hottest possible on Earth, and 0 is completely unusable. In Celsius, 0 has a very useful meaning: below that, it's freezing. And 40 degrees Celsius is really close to 100 Farenheit, so that's not hard to remember either. It is also useful for cooking, because water boils at 100.

But you know what? Let's make a compromise. Keep Farenheit for medical applications, and switch to Celsius for others. If they can keep using Hgmm for blood pressure and kPa for everything else, then they can do this too.

But ultimately the only thing that's intuitive for people is what they are used to. This is the reason they are still using imperial measures, despite the pain of converting between units. And why most people use qwerty. I use that too (actually, worse, I use qwertz).

When I was in high school and taking physics and chemistry, I had a better intuitive understanding of Celsius. Then I ended my formal study of the sciences and had to learn to understand the crazy temperatures weather services were showing.

All I can tell you about Celsius is that 30 is about body temperature, 20 is about room temperature, and 0 and 100 are the transition points of water, but I have a rough idea of every five degree increment between 110F and -20F.

Wait, there are people who open bannanas from the non syem end? Why?

I tried. It didn't turn out nice.

It's much easier to get the peel off that way.

It depends on how ripe the banana is. One that's still partially green will strongly resist being opened from the stem end, meaning that you may have better luck splitting it in the middle. I've never tried opening it from the flower end. If it's yellow enough, the stem end will be easy to open from.

I open it from that end so I can hold onto the stem while I eat it

30 would be dangerously low for body temperature. Normal body temp is about 37 degrees Celsius.

The argument that one system is not "intuitive" always feels like a differently worded argument from familiarity. If you want a system that's "intuitive" even if it's not the first system you ever learned - which should pass for a test of how intuitive a system really is - wouldn't you want a system where the scale is as consistent as possible (as in, the distance between each full number is always the same)? If it's a system that allows negative numbers, wouldn't you want the middle to be in a clearly defined and universally useful point?

Of course, the other way to build an "intuitive" system would be to relate everything to things that almost everyone sees or has. That's how you get "foot" as a distance, for instance. The problem, then, becomes standardisation. Even if you do pick something like the average length of a body part as your starting point, though, I'd still argue that it makes sense that the transition from one unit to the next should always be the same multiplier, and that the steps between each number within a unit should be universal.

That would give you something like: 5 feet is 1 yard (for instance), and 5 yards is the next unit, and 5 of those is the next, etc. (In the decimal system the multiplier is 10, but 5 is the number of fingers on one hand so it makes roughly the same amount of sense.)

It's pretty much all arbitrary. Units of 10 make "sense" because we tend to use a base 10 system. Many of our time units are based off of a base of 60 due to the Sumerians (with the side benefit that it's evenly divisible by the first six integer numbers). Science more or less requires a more standard set of units, but they pretty much all started as completely arbitrary points that then got further refinements as we found better ways to ensure that everybody used the same standard. They started with arbitrary values and kept changing them until the equations agreed. So a meter today isn't really the same as a meter 50 years ago, but it's close enough, and we now have abritrary tests that can be performed to ever-increasing precision to get a value that is the same every time instead of consulting the sacred platinum-iridium rod and weight.

Outside of scientific measurements requiring high precision, people tend to use whatever measure makes sense, generally what they grew up with. Twelve inches in a foot doesn't make any less sense than 1000 millimeters in a meter. Twelve months in a year makes as much sense as the ten months that the French proposed when they were really going decimal-crazy (although the inconsistent number of days in a year could have been fixed). If people are more comfortable with Celsius, that's cool. If they're more comfortable with Fahrenheit, that's cool.

Yes, familiarity is the most important when it comes to being comfortable with each unit. The imperial units started out as sizes of different body parts, which is easy to make approximate measurements with, but more difficult to make calculations than with the metric system, which uses 10 and its exponents as the conversion ratio. Which is good for each meaning of the '10' literal. In our case, it's 10 because we use the base 10 system, which is because we have 10 fingers. 12 would be easier to calculate with, but still, pretty much everyone uses base 10 (tell me a country where they use other if you know one). It would be even more difficult to reform than the imperial vs. metric scale. Not to mention that the metric scale would have to be changed as well.

That in isolation is true, but when you consider that the number of feet for a yard is not twelve, and it's probably not 12 of the lower unit (I don't even recall what that is in Imperial), you see where the metric system has an advantage. It's kind of like how in old British currency, you'd have x amount of pence to get y amount of shillings, of which you need n for a pound, etc. For feet and yards and miles to make the same amount of sense as the metric system, the transition from one unit to the next should always be the same multiplier.

edited 19th Apr '18 4:48:22 AM by BestOf

Right, the metric system is more intuitive to do math with, and has the big advantage that increasing or decreasing by 10 only requires the shifting of a comma, no matter how many times you do so.

The inconsistent number of days in a year can't really be fixed, though, because there are 365,25 days in a year, and a day is still a day no matter how you divide it up.

Yes, the supreme advantage of the metric system is the ability to change your unit scale merely by sliding a decimal point. It's particularly helpful when doing operations with numbers expressed in scientific notation.

Here's an example. Without looking up the conversion, what's the length of the side of a cubic mile in feet? (No points if you memorized it already.)

edited 19th Apr '18 4:20:27 AM by Fighteer

The calendar is a whole completely different matter. The day and the year are not arbitrary measures as an inch or a meter is, but natural measures that directly affect our lives. The month was also this one time. In ancient times many people measured years using the Moon as a reference, thus the month was just as natural measure as the year or the day. Not since Julius Caesar, though.

The biggest problem with calendar is that you need a new one for each year, because the number of days in a year (either 365 or 366) is not dividable by 7, which we use for our work cycle (now this is really an arbitrary unit). I once read about a proposal to fix this by making a year 364 days long, and add a leap year every now and then which includes a complete leap week. Or we could switch to 5 day weeks, but that would make a greater impact because work cycles would need to be completely rearranged.

Supposedly, this was one of the reasons why the French decimal calendar failed. Workers were opposed to getting one day off in ten versus one day off in seven (to be fair, they were supposed to get 1.5 days per ten, but as most workers will tell you, 8 hour days aren't in most industries and when you get half a day off, you'll almost inevitably wind up with only a quarter or so at best because you're expected to work a bit more before you're allowed to leave, seeing as you're already on the site and all). (One of the other reasons it failed, of course, was that it was a top-down change in the system from the government that existed more to reject the current status quo than to add anything better, which meant few people adopted it, a criticism sometimes leveled at attempts to convert countries to the metric system.)

As regards the cubic mile example, that more or less agrees with what I said before, that things like metric get more necessary when doing scientific things. For regular life, you do more rounding.

Actually, I should have said “half a cubic mile”, since a cubic mile is, by definition, one mile on each side. Need caffeine this morning.

It's true that days, lunar months, years, and similar things are what one might call "natural units", which aren't subject to our arbitrary rules, man. But they also are not constants, varying periodically and changing permanently over long time spans.

Hours, minutes, and seconds... yes, those are arbitrary. One could, if one wanted to go insane, redefine a second as exactly 1/86400 of a day but that would create a recipe for insanity as that value isn't constant, ever.

edited 19th Apr '18 5:11:52 AM by Fighteer

When you do scientific calculations, there are machines that do the heavy work, and they don't care which system you use (but you should not mix the two). Scientists usually don't convert anyway. They use one unit for everything. In physics, the standard unit for length is meter and for mass (for whatever weird reason) is kilogram. You don't use kilometers. Except when the measure is so much out of proportions, for example light years for distance or electron-volts for energy (instead of Joules).

In everyday life, however, it's easier to shift commas than do other calculations.

I don't know if kilometres are frequently used in science, but where I live, it's the unit of measure everyone uses for distances that are more than about ½ a kilometre. If know the supermarket I biked to today is about 1km from my home (actually it's a bit over 0.5km on a map, but you have to take a slight detour if you're not going by car). The city centre is about 5km from here. It's about 100km to the town where I'm from, and Finland, from North to South, is about 1000 km. If you want to know what those distances are in miles, it'd take me a while to figure it out. (I know a mile is roughly 1.6km.)

Metres and centimetres are used for everyday things. If you asked me how tall I am, or how big this room is, I'd give it in metres; but for the size of the screen on my TV, I'd use centimetres. (Decimetres aren't used all that much in everyday conversation - but decilitres are, almost as much as litres). If you asked me how tall I am in feet and inches, I'd have no idea.

I think kg, rather than just g, is used for mass because it's maybe a bit more convenient for everyday use. I only use grams when I'm measuring something to follow the instructions of a recipe. For everything else, it's kg all the way. Scientists probably need the smaller measures more (but maybe they're also more likely to measure things in tonnes than I am). The only place I can think of where I encounter measures smaller than a gram are in the packaging of medicine, where it's µg.

I watch/read/listen to enough British and American media that I know one pound is about 0.5 kg (a bit less, but I can't be bothered to round closer than that). If you tell me your weight in stone, though, I'll have to use Google to convert the units.

One pound is 2.2 kg. That's the approximation I use and it's perfectly adequate for everyday calculations.

I think you meant to say 1 kg is 2.2 pounds. According to Google, 1 pound is 0.45 kg.

{nods} And a kilometer is roughly 2/3 of a mile (I always remember that one due to an anecdote about a U.S. motorist getting pulled over for speeding in Canada because he assumed the 90 on the sign meant 90 MPH). An inch is about 2.53 centimeters. A meter is a little bit longer than a yard (39.5 inches to a meter instead of 36).

I always figured the grams wound up so tiny because of they were trying to create a unified system, and a gram of pure water occupies a cubic centimeter (which, as it turns out, is exactly the case). The Wikipedia article claims it's still measured via the sacred physical artifact, "Le Grand K". Is that really still true, or have they found a way to define it specifically?

edited 19th Apr '18 6:18:07 AM by FuzzyBoots

I don't know how you deal with feet, yards, and miles when it takes 36 of this to make the other thing, of which you need 115 to get that one, of which 12½ goes into the big one. I'm sure you get used to it if you live with it, but I sure prefer having 10 of anything be the next unit in line. The only conversion I have to remember is 10.