Handy temperature conversion scale.

When I was 16, I went to high school in California for half a year as an exchange student. I am from Germany and as a junior, I would have had something like my 4th or 5th year of chemistry in school, but out of necessity (or laziness) I took beginner's chemistry.

For exercises I had been paired with two girls who used to try to make fun of me (I think; I never really figured out what their deal was), and asked me stupid questions about myself or Germany. I remember they once asked laughingly whether I like oranges because I was wearing a t-shirt with an orange print.

Well, then one day, there we go. Converting exercises. You have students from 9th to 12th grade in groups of 3-4, trying to convert imperial measurements to metrics. And then metrics to metrics. Basically, for a couple of weeks, we just converted stuff like 14 cm to mm or dm. I forgot so much about my time abroad but the most vivid memory I have is of the girls looking at each other (after a couple of days and repeated explanations) and one says "the decimal system just makes no sense" and the other one quietly and slowly nods in agreement. I ask them how it makes no sense. "Well it just makes no sense." It's just base 10 everything and the rest is practice, it's not different from inches to feet. "No but you see this makes sense. There are 12 inches in a foot", continued by a list of how many shmekels make up a whoopsiedoodle and how many dingelings fit into a hybotron.

I understand how you first have to get accustomed to new units and how conversion might need practice when you aren't familiar with the prefixes, especially when you aren't too experienced in the stem field. But I am still flabbergasted by the statement that having a system where everything is just base 10 and then you shift the decimal point around makes no sense. We are talking about fellow juniors here. How do you make it to age 16/17 never having heard of a decimal point or having trouble with base 10 conversion? HOW CAN YOU SAY IT MAKES NO SENSE?! It's the simplest, most logic based system there is!

IMO metric also allows you to reason about things in your head more easily because doing base-10 calculations in your head is doable.

For example, "Each 1m section of a pipeline contains 20L of oil. The goal is to empty a 200 km section of pipe into trucks. If each truck can handle 20 tonnes of oil, how many trucks would be needed?" In metric that calculation is 20 * 1000 * 200 = 4 million L. 20 tonnes is approx 20,000 L since 1L of water is 1kg, so it's going to be at least within an order of magnitude of that for oil. 4M / 20k = 200.

With US customary units it would be "Each 1 foot section of a pipeline contains 1.5 gallons of oil. The goal is to empty a 100 mile section of pipe into trucks. If each can handle 20 tons of oil, how many trucks will be needed? To handle that calculation you'll have to convert feet to miles. Gallons to pounds, pounds to tons, etc. You can do it on paper, but all those weird conversions add massively to the difficulty.
- There's a reason why the American science community has long converted to metric. You just can't do calculations like this quickly enough.
- well how dense is the oil
  
  Not as dense as those teenagers
  
  True, also i side note. Tanker turks are measured in Volume here. Thats makes it easier
  
  I'm imagining a tank wearing a fez.
  
  tanker trucks
  
  Crude is approximately the same as water, about 0.8 to 0.9 g/mL. But, even if it were significantly less dense, like gasoline (0.74 g/mL) it's still good for an order-of-magnitude calculation. Knowing that 1L has a mass of 1kg is especially useful since many of the liquids we commonly encounter are water-based.
  
  .8 to .9 for crude (where water is 1)
Fuck me we did those conversions in primary school in Italy in the eighties. Can't remember what year exactly but we were prolly 7yo?
- Exactly, we also had this early on. Also with imperial measurements or some random antique ones. I remember the worst conversion exercises were in grade 5, where you had to convert a large number, say 5316, to a number if the base was 8, not 10. This felt completely useless and took a lot of time but it also wasn't necessarily hard. And it made sense because math usually does.
ok how about this america abopts the metric system but every moves on to base 12.
- Fifth grade prepared me for base whatever, bring it on
  
  Ok in base pi what is 10
  
  Oh that's a great question, we only did integers as bases - my guess would be 100.58 (or 100.18)? But I absolutely admit defeat here.
  
  Non-integer base, anyone?
  
  2i is also fun

It may be that or it may be that our entire educational system has turned into shit through decades of low pay for teachers weeding out all the best people.

I am a US STEM professor.

Prove it! What is the speed of light in anacondas/average Snapchat duration?

Edit: around 10^11 anacondas per average daily snapchat usage among US teens

Does the person on Snapchat have buns? 'Cause otherwise my anaconda don't want none, hun.
- Isn't there a filter for that?
2! No, 3!
5 Snapacondas

I have a theory that Americans are great at math because they regularly work with base-12 systems.

That would be cool if true. But then they use measures like subdivisions of an inch in base 8 increments.
- It's closer to a binary system, since it's iterative division by two. Half inch, quarter, eighth, sixteenth and so on.
  
  People do the same thing in metric, but they just prefer to write 0.125 cm instead of 1/8 cm.
  
  Imperial units are a bit more heavy on rational numbers instead of decimal.
  
  The base 12 stuff comes up with things that were historically cut in halves as well as thirds.
  It's all highly composite numbers, since they're easier to work with if you're doing repeated division in your head. Ten is only divisible by 2 and 5 before you start to get a lot of rapidly growing decimal parts. 12 is divisible by 2,3,4,6.
  If you've got a balance, a knife and a stone we all agree on the weight of (let's call it a pound stone), it's easy to measure our a half or third of a pound, and halves or thirds of any other portion I can produce.
  Over time, common divisions got names and a system of units was produced that was entirely inconsistent but liked 12 and 60 because of ease of use, and powers of two because you can just keep cutting them in half.
  
  It's all moot since we can use a scale now instead of a balance with a rock, and we can trust measuring tapes instead of repeatedly bisecting a plank, but it at least gives context to why it prefers fractions and numbers like 12 and 8.
And base 3 sometimes (yards). When taught well, there's a ton of value in learning to quantify the world in a variety of base systems.

Not uniquely American, but thinking in base 7 (weeks), base 12 (years, hours, feet), base 60 (minutes), base 3 (yards), base 10 (the default unless told otherwise), etc. really helps you adapt and estimate a number of other, unrelated, things.

My professor for my first real engineering class had an excellent quote, "A good engineer can work in any unit system."

There's actually quite a lot of advantages the US could have in math education if we properly harnessed both unit systems. Becoming fluent in both and regularly doing conversions would give students a lot of real world application and simple math practice.

A good software developer can also work with any language, but if you're going to use Javascript to build an enterprise level software you are guaranteed to have a bad time.

You use what is best for the job and from my understanding there's really no benefit to using imperial measures over SI, beyond the familiarity of growing up with them. If you were taught SI units from the very start you wouldn't ever use imperial.
- There are actually reasons to use imperial, but it's all inertia. Industry has a bunch of controls and correlations and empirical equations that use imperial, so the inputs all need to be imperial too.
  
  Of course, you could always do it in metric and then convert at the end. That's one approach to unit systems.
- if you're going to use Javascript ~~to build an enterprise level software~~ you are guaranteed to have a bad time
  
  ftfy. also applies to Python for any code you plan to use for more than 1 day
Or you end up doing what I do to troll my friends, and mix the styles the systems like.
"This post should be 5/16ths of a decameter" The rational numbers you find in imperial are helpful for dividing things compared to decimals, but everyone gets all weird when you do fractional meters or kilograms.
- I like to measure the area of rooms in foot-metres. Square foot-metres is a great unit for volume.
  
  Today I unironically described the length of something as "about 1 centimetre less than a foot".
- And I just understood why that’s the case. Most of the old units used highly composite numbers as factors, which have an incredibly high number of divisors. We still widely use such factors for time and angles.
  
  4: 1, 2, 4
  
  5: 1, 5
  
  6: 1, 2, 3, 6
  
  10: 1, 2, 5, 10
  
  12: 1, 2, 3, 4, 6, 12
  
  20: 1, 2, 4, 5, 10, 20
  
  24: 1, 2, 3, 4, 6, 8, 12, 24
  
  50: 1, 2, 5, 10, 25, 50
  
  60: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60
  
  100: 1, 2, 4, 5, 10, 20, 25, 50, 100
  
  120: 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120
  
  360: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 60, 72, 90, 120, 180, 360
  
  840: 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28, 30, 35, 40, 42, 56, 60, 70, 84, 105, 120, 140, 168, 210, 280, 420, 840
  
  1000: 1, 2, 4, 5, 8, 10, 20, 25, 40, 50, 100, 125, 200, 250, 500, 1000
Some metric system just don't offer a single benefit compared to others

Clocks and calendars must give you nightmares...

Counting days suck ass. Quick, how many days during next 3 months? How many weeks is 95 days? How many weeks is 666 hours?

Our time and date is pretty much locked in, but it does have some limitations
- During the French Revolution they tried to create metric time units, but it didn't stick.
  
  The one thing I think is possible within our lifetimes is getting rid of time zones. Instead of a business being open from 9:00 EDT to 17:00 EDT it could just be 13:00 UTC to 21:00 UTC. Then it's much easier to schedule things with people in other parts of the world. China is already kind-of doing that, the entire country is on China Standard Time, even though it's a huge country. That means that the sun is directly overhead at approx 3PM CST in the far west, and at the equinox the sun will rise at about 9am and set at about 9pm.
  
  I mean, you can do that today. Just post your hours and schedule your meetings in UTC.
  
  Tineszones exist because we have two uses for time: the linear progression of the universe, and "where is the sun and what am I doing in the day".
  To communicate across wide stretches of the earth, you need a way to know where the sun is wherever the person you're talking to is so you don't call them in the middle of the night when they're asleep.
  We'll always have something that lets us lookup "is the man in Madrid likely asleep if I'm eating lunch?”.
  Tineszones work well for this because I can see that Madrid is gmt+1 and I'm gmt-5, so if I'm eating lunch they're probably not in bed, because it's 1800 there.
  
  As long as humans care about where the sun is in the sky for how we order our days we'll need timezones, even if we reinvent them and give them a new name.
  
  Tineszones exist because we have two uses for time
  
  Not really. Time zones exist for 1 reason: it was too difficult for each town to have its own time, especially when it came to train schedules. So, they were organized into zones so that 6pm in Baltimore and 6pm in Philadelphia were the same. But, people were still used to having 12 pm being the time when the sun was at its peak, so NYC was put in a different zone from Los Angeles.
  
  To communicate across wide stretches of the earth, you need a way to know where the sun is wherever the person you’re talking to is
  
  You normally don't need to know where the sun is, you need to know if it is normal business hours. Or, if it's a friend, what their schedule is like and if this is a convenient time for them. You can search for the time in that other place and guess that maybe their business hours are 9 AM to 5 PM, but that isn't always true across companies and especially across cultures. What you really need to know is something like "what are Dimitri's business hours" which is easier if everyone uses UTC. If you ask "What are Dimitri's business hours" and you get the answer 8h - 16h EET, now you need to figure out what "EET" means. But, if you get 6h - 14h UTC and you're also using UTC, there's no conversion needed.
  
  is the man in Madrid likely asleep if I’m eating lunch?
  
  If that's what you need to know, what you really need are the current UTC offsets used to describe time zones. Just store those as "sun offsets" relative to cities and nuke the time zone aspect.
  
  See, at the end? What you're describing is timezones with a different name, and more fine grained so we have more of them. This makes it harder.
  
  Business hours are correlated to where the sun is, which is why I used the sun as a stand in for "how people progress through their day as mediated by our biological day night cycles".
  
  People communicate with people in parts of the planet where everyone would say it's a different time because the sun is in a different part of the sky.
  Lumping places together by rough sun position is better than every town keeping their own time.
  
  Jumping through hoops to avoid saying that our sense of time is linked to the location of the sun in the sky is just making things more complex than it needs to be.
  
  Again, we already have UTC. People use it where it makes sense.
  
  See, at the end? What you’re describing is timezones with a different name, and more fine grained so we have more of them. This makes it harder.
  
  No, timezones are intended for people who live in them to be in a time that's roughly coordinated with other people living in the same area. I'm saying that's unnecessary. There's no reason that 12:00PM should be close to the time that the sun is at its peak. That already isn't true for people in the west of China. For them it's normal to think that 3PM is when the sun is at its peak. What I'm suggesting is that that be applied worldwide.
  
  If, for some reason, you want to know where the sun is relative to someone else on the planet, there are plenty of ways of doing that. I suggested some. That doesn't mean that you need time zones.
  
  Business hours are correlated to where the sun is
  
  There's a correlation, sure. But that isn't enough information to know if a business is open, especially if it's a business in another country which has different cultural ideas about when things should be open. Business hours are no reason to stick with clunky time zones.
  
  People communicate with people in parts of the planet where everyone would say it’s a different time because the sun is in a different part of the sky.
  
  No, they say that because it's what they're used to. If they were used to using UTC they'd say it's the same time. They already do that for some things, because time is understood to be related to causality. As in, "Did that happen before or after the bridge collapsed?" People in different time zones will agree that in that sense, time is the same for everyone, even if they're using a different time zone for historical reasons.
  
  Again, we already have UTC. People use it where it makes sense.
  
  And don't use it where it would also make sense for historic reasons. People also use US customary units not because "they make sense", but because of historic reasons.

Are you at a school known for its math or engineering offerings, teaching applied or theoretical students primarily? There's quite a bit of variability between schools in US.

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