The super-slow conversion of the U.S. to metric (2025) • Hacker News Board

Re: The super-slow conversion of the U.S. to metric (2025)

#211

Post by bluGill » Wed, Jan 21, 2026, 5:04 PM UTC

bluGill wrote: post #67

c048 wrote: post #30

Earlier quoted context omitted.

I've heared Americans, unironically, state that the metric system is less precise than the imperial system. I have no clue what the origin is of this myth, but at this point I wouldn't be surprised if Trump held this belief too.

Depends on the field - it happens that 1\1000 inch is a good tolerance for many machining operations, while metric doesn't have a convient round number close enough to that range to be useful. That doesn't slow down mathinists though, they know the fraction of mm tolerance they need to use and it is what is marked on their tools.

To give an opposite examples, in metric your speed limits are multiples of 10, in the us multiples of 5. Either works but metric has a better tolerance. deca-kilometers perhour would be even better - but no such prefix exists.

Re: The super-slow conversion of the U.S. to metric (2025)

#212

Post by IAmBroom » Wed, Jan 21, 2026, 5:05 PM UTC

shoxidizer wrote: post #101

ericmay wrote: post #86

Earlier quoted context omitted.

> Yeah, we went over the Metric System that whole year. I can still sing the "Metric Family" song from the film on metric units ("Kilo", "Milli", etc.). And to my young an impressionable mind, the U.S. was joining the rest of the world "Free World" in a kind of Star-Trek-like casting aside of the old things that divided us—joining each other with a focus on progress, science, space… I’ve always found this peculiar be…

Frank Llyod Wright lacking warmth and humanity? Never been to Falling Water?

I love FLW, and Falling Water (which I've toured), but yeah: his art tends to be cold, abrupt, and ... unsnuggly.

Re: The super-slow conversion of the U.S. to metric (2025)

#213

Post by roryirvine » Wed, Jan 21, 2026, 5:05 PM UTC

bryanlarsen wrote: post #58

plaguna wrote: post #44

Earlier quoted context omitted.

"Fahrenheit is a bit more convenient for describing the weather" - you might need to show us an example here that is not biased. Because to me, Celsius is a bit more convenient for describing the weather.

Not as laughable as "metric is more convenient for human scale things". "Human scale things" includes fractions of an inch and fractions of a mile, which are horrible in customary units, and includes both the foot and yard which are used confusingly interchangeably. Metric is far superior for human scale measurements. And that's only length. It gets worse outside of length. Like WTF is an ounce?

And using different ounces for metals, fluids, drugs, and, er, everything else - how does that not send people screaming into the arms of the metric system?!

And then there's the hundredweight, where "hundred" actually means "eight"...

Re: The super-slow conversion of the U.S. to metric (2025)

#214

Post by toolslive » Wed, Jan 21, 2026, 5:08 PM UTC

technothrasher wrote: post #149

ericmay wrote: post #86

Earlier quoted context omitted.

> Yeah, we went over the Metric System that whole year. I can still sing the "Metric Family" song from the film on metric units ("Kilo", "Milli", etc.). And to my young an impressionable mind, the U.S. was joining the rest of the world "Free World" in a kind of Star-Trek-like casting aside of the old things that divided us—joining each other with a focus on progress, science, space… I’ve always found this peculiar be…

> the useful scale of Fahrenheit is far superior 0-100 versus 0-32. Well, first of all, I'm not sure why you're defining those scales as the "useful" ones. They don't even equate to each other. But why are you arbitrarily using 100 as the end of your Fahrenheit scale? Just so you can declare it 'Metric-y'? If you read his paper, Fahrenheit's scale is actually 0-96.

As an engineer, you should not even use temperature at all. All thermodynamic formulas simplify (a lot) if you use the inverse temperature.

Re: The super-slow conversion of the U.S. to metric (2025)

#215

Post by quesera » Wed, Jan 21, 2026, 5:12 PM UTC

JKCalhoun wrote: post #77

"Back when I was a Catholic-school kid in northern Wisconsin, my school lessons briefly focused on the metric system. This was in the late 1970s." Man, the progressive school (Comanche Elementary in Overland Park, Kansas!) must have had a huge impact on my life. In addition to open classrooms (I was in Unit 5, not 4th Grade), team teaching, a focus on experimental science, a circular layout to the school with a sunke…

The US Metric Board was cancelled in 1982 by one Ronald Wilson Reagan (anagram: Insane Anglo Warlord).

RWR and the charismatic traditionalism he espoused have caused a great deal of harm to American society.

Metrication is not at the top of that list, but it is one of many examples that we still live with today.

Re: The super-slow conversion of the U.S. to metric (2025)

#216

Post by nearbuy » Wed, Jan 21, 2026, 5:12 PM UTC

ericmay wrote: post #166

technothrasher wrote: post #149

Earlier quoted context omitted.

> the useful scale of Fahrenheit is far superior 0-100 versus 0-32. Well, first of all, I'm not sure why you're defining those scales as the "useful" ones. They don't even equate to each other. But why are you arbitrarily using 100 as the end of your Fahrenheit scale? Just so you can declare it 'Metric-y'? If you read his paper, Fahrenheit's scale is actually 0-96.

Well even 0-96 would be better, but I think 0-100 scales are more useful. Temperatures in most places are within those bounds and it's like a test you are graded on. You get a 0 on the test, that's really cold. You get a 100 - smoking hot. I'm not 100% sure of the normal upper/lower bounds in everyday life for most people on the planet for Celsius, but let's say it's 0-32. It' just feels weird to me to be operating o…

I think you're saying that where you live, the weather is usually between 0 and 100°F. Aside from the fact that outdoor temperatures aren't in this range everywhere, we don't only use temperature for weather.

100°F is warm to the touch, not smoking hot. 100°C is boiling hot. You sip tea at 60°C, and brew it at 80° to 100°C depending on the type. You cook chicken to an internal 74°C. A hair dryer blows air around 50°C. All of these are outside of 0-100°F.

> I generally just prefer the Imperial system because of its practicality in everyday life

Funny, most of us much prefer metric mainly for its practicality in everyday life.

Edit: I'll add that aesthetically, 0°C is a really nice zero point for weather. Above 0° is the temperature that the snow starts melting, below is when the streets and ground starts freezing. Which side of 0°C you're on is the biggest pivot point for what it's like outside of any temperature.

Re: The super-slow conversion of the U.S. to metric (2025)

#217

Post by Kim_Bruning » Wed, Jan 21, 2026, 5:14 PM UTC

ghkbrew wrote: post #168

btbuilder wrote: post #130

Earlier quoted context omitted.

0C = Frozen!

Only if you're made of pure water at standard pressure. Which I'm not.

Close enough for government work, actually. And it's not just flesh. Lots of things behave approximately like water, which is handy for all sorts of back-of-envelope estimates.

Re: The super-slow conversion of the U.S. to metric (2025)

#218

Post by mindslight » Wed, Jan 21, 2026, 5:14 PM UTC

FeloniousHam wrote: post #177

JKCalhoun wrote: post #77

"Back when I was a Catholic-school kid in northern Wisconsin, my school lessons briefly focused on the metric system. This was in the late 1970s." Man, the progressive school (Comanche Elementary in Overland Park, Kansas!) must have had a huge impact on my life. In addition to open classrooms (I was in Unit 5, not 4th Grade), team teaching, a focus on experimental science, a circular layout to the school with a sunke…

I understand existing-tool-holder opposition to a new measurement system, but sweet mother I hate fraction math.

I keep trying to make myself think in terms of 32nds. For example think of a 9/16 wrench as "18", the 1/2 wrench is just "16", and so on. It's a slow process. I want to standardize on some color code for easy cross-brand identification of wrench sizes too, but I haven't come up with a compelling scheme.

The worst is the hardware. I inherited a full assortment of #2-#10 stainless SAE UNC hardware from a business move (already in nice parts drawers, too). It was pretty awesome for just having whatever I needed on hand to build things. But now as I maintain more and more things that are metric native, I've been building up the assortment of metric threads as well.

I suspect this is one of the real pain points of fabricators (plus taps/dies). And I'm guessing they're still still Imperial native due to existing tooling, making the conversions not clean (it's easy to convert 1/2 inch to 12.7mm and measure that, but it's not straightforward to convert 10mm to 0.3937 inches (25.2/64ths) and measure that.

Re: The super-slow conversion of the U.S. to metric (2025)

#219

Post by ahmeneeroe-v2 » Wed, Jan 21, 2026, 5:15 PM UTC

JKCalhoun wrote: post #77

"Back when I was a Catholic-school kid in northern Wisconsin, my school lessons briefly focused on the metric system. This was in the late 1970s." Man, the progressive school (Comanche Elementary in Overland Park, Kansas!) must have had a huge impact on my life. In addition to open classrooms (I was in Unit 5, not 4th Grade), team teaching, a focus on experimental science, a circular layout to the school with a sunke…

>no doubt buoyed by having put astronauts on the Moon

NASA did this using customary units

>I've been missing it my entire life since

Surely you've learned by now that you're missing childhood, not an actual thing about the US? I'm asking this as someone who does think this era was peak Americana, but for totally different reasons than you present, and having not been alive then myself.

Re: The super-slow conversion of the U.S. to metric (2025)

#220

Post by t-3 » Wed, Jan 21, 2026, 5:15 PM UTC

kakacik wrote: post #138

t-3 wrote: post #59

Earlier quoted context omitted.

Honestly, I don't think anyone would raise much of a fuss over changing distance measurements to metric. Both centimeters and inches are easy enough to eyeball or rule-of-thumb, meters and yards are basically the same, and larger units are only relevant for speed limits and travel planning. Metric lacks a good "foot", but I guess people would get used to eyeballing things in ~50cm increments instead. Weights are even…

Now sure what sucks on Celsius, water freezing and boiling have been some of the most important scientific and just plain existence facts of mankind since we evolved. We humans have 10 fingers so its split by decimal system. Since we humans operate 99% of our existence in a narrow band between 0 and 100 degrees celzius, I'd say its more important than starting from absolute 0 and dealing constantly with big offsets.…

In Celsius, my daily life uses values from ~ -20 to +30 for the weather, but from ~0 - 90F. For cooking both are equally arbitrary, as the only place I set or read a temperature when cooking is candymaking, setting the oven, or cooking large amounts of meat.