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Comment by chrisseaton | Hacker News Reader

Is it just older people in the US who want to keep using customary units? Does the younger generation use metric and they'll switch over time?

I don't think I'd have the mental arithmetic required to calculate things in terms of sixteenths!

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The human eye is really good at dividing things in half, so it's easy to make power-of-two divisions without special tools. Just divide whatever it is in half, then divide it in half again, and so forth until you have a sixteenth.

The US system has lots of power-of-two factors in it, which suggests that it was born in the marketplaces and workbenches of people who did most things by hand, rather than our modern world where we design everything on paper first.

It’s just a hassle to switch things when you have a large number of people who have adopted it. Even the UK which is nominally metric hasn’t had the will to switch from miles to kilometres for road speeds and distances. The slow spread of globally used volumes is probably the only way it’s ever going to happen and even there it won’t affect most areas.

There does also seem to be a more extreme reluctance in the US to change to more widely adopted units and conventions (e.g. day/month/year) and if anything being one of the only countries left using non metric units seems to be a point of pride. About the only SI units the us seem to use relate to fields invented after science as a whole adopted it as standard (e.g. electrical units).

In one sense inches have a pleasant form of being subdivided into more easily divisible Power of two units but even that falls apart over small distances where they turn to ‘thousandths of an inch’ rather 1024ths. Useful in a world of pre-computer drawing because you could easily scale up plans but not particularly useful now.

There does seem to be a particular reluctance in the US to change things "because everyone else does it this way."

It even goes beyond that though. Although this is on its way to becoming a largely academic point, the US also hasn't changed the bills and coins in common circulation for probably close to 100 years. We still have a penny, the dollar coin didn't take off (which I'm actually fine with as I prefer a bill for a $1-$2ish denomination), and you still can't count of being able to use $100 bill at a random store in the US.

Exactly. Drill sizes and, even worse, screw sizes drive me crazy. It's not even obvious which one is larger without doing math.

This reminds me of the great Mythbusters who, to me, came across a bit stubborn to insist on US units -- it felt unsciency. I do understand that they wanted to use the 'normal' system that 'normal' people use -- I always recalculated all their psi and inches of mercury and fathoms per fortnight to SI.

So weird!

Mythbusters, like all (US) television, needs to relate to a US audience, at about an 8th grade reading comprehension level.

That means favouring Imperial over metric units. They'd lose the audience otherwise.

I'm a big fan of converting to Celsius. It would probably be the cheapest thing to switch to.

Kilometers? We have more than four million miles of road in the US, and lets rough-guess at the VERY least two speed signs each mile, one each direction. The real number on average is probably double that.

Then there are "mile markers" and every freeway sign that lists distance by miles.

Then there are cars that don't have highly visible kM speedometer markings.

Specific industries may shift to metric, and surely things like surveys probably could. But the total conversion? I would bet on many structural changes in the United States before that ever happens.

Voting reform, Constitutional amendments, DC and PR statehood, banning reality TV, all seem more likely than moving to metric.

Honestly, there's probably less justification in switching to Celsius than other units. Pretty much the only place Fahrenheit really falls down is that it's different from the rest of the world--and the vast majority of Americans are not exposed to that difference on a day to day basis.

Yes, you need to remember what the rather arbitrary seeming freezing and boiling temperature of water are, but that's not a big deal. And you actually get a finer grained measurement system without resorting to decimals. And you're less likely to need negative numbers for ordinary temperatures. (And, if you do, you know it's really really cold.)

Finally, while the Celsius degree size is used in a lot of technical calculations, the absolute scale isn't usually. Kelvin is used instead. So if anything were the "right" unit to use it would be Kelvin, but that would be fairly obviously silly for day to day use.

In my field of research (condensed matter Physics and Thermodynamics), the split between Kelvin and degrees centigrades is about 50%. Anything that gets in contact with industry tends to use °C for some reason.

When I was doing material science (long time ago), as I recall we'd obviously use Kelvin for calculations where you needed to use an absolute temperature scale. But if we were just stating an annealing temperature or something like that, we'd use Celsius.

> two speed signs each mile, one each direction

More like 10 miles on interstates and rural roads.

Perhaps mile markers could be re-used since the only have the number...

But yah, seems unlikely.

I'm the opposite. I'm all for switching to most metric units but there's nothing appealing to me about Celsius. I can't think of one instance in my life where knowing that the boiling point of water is a particular temperature was useful. Every time I've boiled water it has been without the assistance of a thermometer. The freezing point has been somewhat more useful since ice can be a safety hazard and is part of typical weather in many parts of the world. Even then, there are many other variables involved that make the exact temperature of 32 or 0 worthless since ice on the sidewalk or pavement isn't going to form at exactly that temperature.

In know in engineering and science courses we are taught mostly metric with a bit of imperial. In something like structural engineering you need to be more familiar with imperial because the architects and construction crew would work in imperial. But a chemist would fully work in metric. Day to day life it remains imperial because people are familiar with it and there is no point in switching everything. The fractions are harder for many people but you can use decimal feet or pounds most of the time.

We were switching to metric in the 70s but Reagan reversed the process, "to own the libs" before that phrase had been created.

https://en.wikipedia.org/wiki/United_States_Metric_Board

The US Metric Board also wasn't really getting anywhere and didn't have a Congressional mandate. [1] I'm not sure you can really blame Reagan for getting rid of an ineffective government organization that was being publicly ridiculed.

[1] https://en.wikipedia.org/wiki/Metrication_in_the_United_Stat...

Everyone in US uses feet and inches, afaik.

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