Why A4? – The Mathematical Beauty of Paper Size | Hacker News Reader

Why A4? – The Mathematical Beauty of Paper Size

scilogs.spektrum.de

750 pointscasca608 comments

A4 is so ubiquitous around me (Europe) that, no matter its merits or not, it's really a major PITA when you get documents that are not A4. They don't line up nicely with the A4 stuff. They don't go gently in the A4 folders / sleeves / pockets / ring binders (files) / etc.

Typical offenders in my case are medical bills printed on dot-matrix printers.

I don't even know if there's perforated continuous stationery/form paper with tractor holes that, once you strip the holes, is A4 sized? I guess it's really uncommon if it exists for I don't ever recall seeing any actually used.

Now don't get me wrong: hearing the song of a dot-matrix printer makes me happy (brings back lots of memories as my first printer was a dot-matrix one) and it's nice that that tech is still in use here and there. I just wish the dot-matrix printers in Europe would use A4 continuous paper (which may or may not even exist).

And don't get me started on oversized continuous paper that is not perforated: this is the kind of stuff that can trigger obsessive-compulsive disorder!

I guess all this rant to say that even in Europe, where A4 is ubiquitous, you still have places using other sizes than A3/A4/A5 etc.

I had this problem too, with majority of documents being A4, but a single bank/med bill ruins the rest of the stack.

My solution was to just give up on keeping the documents unless I have to, for legal/tax purposes, and just digitally archive them. Modern scanner apps are super good, and the OCR/search features make the 20 seconds it takes to scan it and throw away the paper.

Honest question: why do you archive things you don’t have to archive?

For easier searching and sometimes nostalgic reasons.

When I was in my early 20s, I used to save ticket stubs, boarding passes, train tickets, etc when I was traveling, I really liked keeping them. But when I saw myself becoming a borderline hoarder, I took photos of them and threw all of them away. Even today, I have the habit of taking a document image of ticket stubs and other new things, specially when I'm in a new city or a country.

There is no practical use for them, just that they help me to not stack up physical papers.

The other real documents I archive are mostly documents related to dividend notices, water/electricity bills that unfortunately come in snail mail, etc. I'd be fine if I don't keep them, but I have them in the very unlikely scenario that I just might need to make a paper trail.

I have a bunch of stuff I wish I could easily digitize and throw away the originals. But, aside from doing a few selective things, the effort to en masse digitize and add enough metadata so I could actually find stuff isn't worth the return.

For some people "please provide evidence of your previous travel history" is something to worry about. Will they accept digitalized version? Who knows!

I would have absolutely no systematic record of my travel history outside of stamps in a passport and TripIt.

Passports tend to get lost, and replacement won't have the stamps. Whether this matters for you mostly depends on your citizenship.

Certainly for some nationalities getting visas is harder than others. Though I'm not sure what would even constitute proof beyond passport immigration stamps and you don't necessarily always have those. Most boarding passes these days are either just printed out on a printer or displayed on an app. I'd actually have a pretty good record going back maybe 20 years with TripIt but that doesn't seem as if it would be considered authoritative.

Not the parent but: because you often don't know with certainty whether a particular document will be needed at some point in the future.

Edit:

Concrete example: I'll probably never get audited by the IRS, but if I ever do, I really really want to have all the records I need to defend myself.

For the IRS, you only need to keep documents seven years back. Anything older than seven years can be shredded.

So everybody must keep 7 years of archives? Is that why houses in the US are so big? And does everybody have an archival room? Or does the IRS accept scans? So many questions.

How many documents do you have??? Surely one smallish box would do for most people?

Some people, yes. Others, no.

As your finances get more complex, and you change employers more often, and you have more 401k plans that are distributed around various companies, and you have multiple credit cards, etc... then your storage requirements will necessarily increase.

Essentially all such records are available online. In any case, a file cabinet is almost certainly sufficient if you want to save a few years of printed copies.

You still need to provide your own copies of that information, which can be verified against other sources. If you can't provide that information, then you're likely to not do well during the audit.

So, you do want to make sure you've got your own copies of those files, whether hard copy or scanned.

But for 99.99% of US citizens, a single file cabinet is likely to be more than enough.

In theory, yes. In practice, I think most people probably don't.

I think scans would be acceptable, but you'd probably have to verify those claims with the bill sender.

Houses in the US being so big has less to do with storage requirements for tax filing documents than everyone wanting to stay above average for everything, including house size, and home builders and real estate agents profiting greatly from the general FOMO.

You can always "reconstruct the file" in order to replace lost physical documents, assuming there are digital copies elsewhere.

The IRS and the courts may lose files occasionally. Then there are fires, like the government records Missouri fire: https://www.archives.gov/personnel-records-center/fire-1973

It happens.

I tend to throw things in a drawer or other container and throw most of it out every few years. I figure that was, if I need something, I can probably find it. But I don't have to go to the work of filing the 99% of things I'll never need up-front.

That's what I do. All bills, statements, etc. go into a cardboard document box. I start a new box every calendar year. If I ever need to find anything, it's a bit of a search but not too bad as the papers will be in roughly chronological order.

I almost never need to find anything.

It's a decent compromise between separate files for everything (which would take too much effort) and not saving stuff at all. Even scanning stuff to save digitally is more work than this system.

After 3 years the box gets burned.

The exception is tax returns, they get saved separately.

3 years is a bit short. In the last year or so, I've twice needed to find old documents -- ~5 and ~7 years old, respectively.

I keep receipts for significant purchases (electronics etc) in one envelope per year. It's so little space I keep these indefinitely, so if I sell an 8 year old bicycle I should still have the receipt.

Everything else is in an A4 (now this comment is on-topic) file, and with so much being electronic these days it takes a decade or more to fill one up.

I do file some things away (e.g. stuff I know I'll need to do taxes) and certain other things (like insurance) go into a fireproof box. But, for the most part, I do much less organization of paper than I used to, especially of things that I can probably just find in an online account. I have file cabinets but I rarely open them these days. Most of the paper I systematically save is going into my travel destination boxes.

For me it's a "you never know" situation. The cost of being wrong about this can be very high.

My mother kept the first utility bill of the year for electricity, natural gas, water and sewer, etc. She lived in the same house for 42 years and liked to be able to see how much the amounts had changed over the years.

I’m not sure it was tremendously useful but she could verify her feeling that water and sewer increased disproportionately to the others, for example.

How does she remember to do that every year? That's amazing.

How do you know you don't need to archive it?

Recently a colleague needed to provide 20 years of details of addresses lived and trips overseas made in order to complete various immigration forms.

Governments can change their demands at their whim. If you don't have the documents, you're screwed.

I guess it happens but, while I've lived in the same house for many years, I wouldn't remotely have any real proof of overseas travel except for passport stamps and whatever is recorded in TripIt (which I assume wouldn't constitute proof). We're taking dozens and dozens of trips. I suspect very few people save that type of information unless they know in advance they'll need it.

If you never move, and certainly never travel between countries, then you are probably OK. But honestly, you don't know. Governments can and do change the laws when it suits them.

Here's another specific example. It's not just the initial tweet, you can see example after example in the discussion:

https://twitter.com/OmidVEbrahimi/status/1558024348132327424

You're not in the same position, I assume you were born in the USA. But do you really trust the Government not to change the laws? And what if you want to accept a contract or employment in another country?

How much would you need to have archived in those circumstances?

Are you sure?

Personally, having lived and worked in four countries, I archive pretty much everything.

I have box that papers I need to keep goes into.

The theory is that it's highly unlikely that I'll ever need to produce/find the papers every again.

So if I have to, I'll pay the cost of sorting and organizing the papers when that day comes.

Kind of like lazy evaluation in Haskell :)

> I don't even know if there's perforated continuous stationery/form paper with tractor holes that, once you strip the holes, is A4 sized?

There is. We had an ImageWriter in the 1980s which printed on exactly that. Until i read your comment, i assumed that was the standard!

This format still exists, for example:

https://www.paperstone.co.uk/paper/listing-paper-computer/5-...

Technically it's 0.66 millimeter shorter than A4. A bigger problem is width, it does not fit the "standard" 80 columns.

That paper does make me irrationally angry for one reason:

"Sheet size is A4 - 11.66inch deep x 235mm wide (edge to edge including sprockets)"

(Edit: Although it does make a sort of sense, in that dot matrix line height is in inches - but still aggravating).

The line height of a dot matrix printer is 1/6", so A4 continuous paper would be roughly 70 lines but not quite exactly 70. Breaks would be messed up after a few pages. It would also not fit 80 characters horizontally. That's why continuous paper is stuck with US letter or 14"x11" format.

I am sure someone has already pointed this out, but there is indeed A4 sized tractor paper. Old person irrelevant anecdote, in the days before affordable high resolution inkjets laser printers, 9-pin dot matrix, 24-pin dot matrix and daisywheel/golfball printers ruled the world.

Submitting coursework in college was required to be on A4 paper, and if you used a dot matrix printer you lost marks too. Some of my college professors, even on my computer science undergrad were so stuck in their ways that they demanded you type everything up on a manual typewriter and would penalize you if they thought you had done it on a computer.

College students were lazy, so everybody would use the college's 9-pin dot matrix printer (losing points) and then mad dash for the single guillotine cutter in the adminstration's office like they were French royalty in 1789. I special ordered very expensive A4 tractor feed paper, and bought a second-hand daisy wheel printer that nobody wanted because daisy wheels didn't do graphics, and typed everything up on a computer. No lost points, no lining up to use the guillotine, no mad dash at the end.

But yeah, places using sizes other than A4, screw those guys.

I would suspect the software was written for a non-A4 format, so if you were to put A4 paper in it you might get line wraps that would screw up multi-page prints.

Oh my, I just remembered the pain of setting the perforation skip when using nonstandard paper. And then realizing that those problems were a luxury compared to the problems big professional office printers throw up today.

That satisfying tearing of the perforated tractor feed edges. And the not so satisyfing tear when you tried to do too many at once because you were in a hurry.

Wide format tractor fed music paper in green.

I had tractor fed graph paper for a while. If you want to know frustration, try lining up your DnD game maps to that...

And I had forgotten about the perforation skip/misalignment. Thanks for bringing that back. Triggered.

IDEA: Someone please make a "white noise" generator that play audio of old computer 'whirring' noises... like a dot matrix printer, a fax machine, a modem, etc... that plays low-key in the background...

I actually miss the sound of a dot-matrix.

Not just white noise but whole songs

https://youtu.be/VXbP7OkQ8LQ

HOLY SHIT!!!

That was my first printer ~1986 or so.... gosh I wish I still had it.

Make it play the Windows 95 sound...

(the guy who wrote the win95 startup sound was paid $30K)

This is pretty amazing though:

https://youtu.be/pX4tBIwhOqY

Search for "old computer asmr" gave me this: https://youtu.be/tt3kYcHbbLg?t=160 (link right to the relevant part).

OMFG thank you!!!

16 v 33 bitch

The excellent MyNoise.net website has a couple that may match:

"Vintage Office" [1] has a Dot Matrix printer.

"Calm Office" [2] has a Printer/Scanner.

[1] https://mynoise.net/NoiseMachines/vintageOfficeNoiseGenerato...

[2] https://mynoise.net/NoiseMachines/openOfficeNoiseGenerator.p...

YO!!!!!

I am a sup[er fan, and subscriber to that site!!

I am happy that others know about it!

That brings back the memories. I was one of the first students to submit a word processed paper at my college. "Just in case," I had bought a cheap and slow daisywheel printer. I cooked up this idea to prepare my pages with correction fluid before printing them, but never found it necessary.

I ended up asking one professor if it was OK to use word processing. He said, just this once. The next week, there was an all-faculty meeting (small college), and they actually discussed whether word processing should be allowed. The profs who were already using word processing spoke up in its defense -- from the physics department. They reassured everybody that the computer was not doing the writing. The college came out with a statement saying it was OK, but that we were on our honor to not use a spell checker.

By the time I graduated, every prof was using a word processor.

What I don't think the profs figured out, for several more years, was how to grade a paper that's mechanically perfect. All of my papers got A's, and I chose courses where the grade was based solely on written work. I think in terms of efficiency and aesthetics, using a word processor bumped my GPA by easily half a point by graduation. I was already a good typist thanks to programming.

Many years later, when my kids were in grade school, the writing assignments included formatting requirements, including margins in inches, for documents that would never be printed. These requirements came from the ironically named "Modern" Language Association. Today, teachers say, any format you want, just get it in by the deadline.

I'm still waiting for the US to convert from letter size to A4. The change feels imminent, but for some reason it hasn't happened yet. Maybe we need to convert to the metric system first?

Why does it feel imminent?

Honestly it's a lot easier to have bespoke paper sizes now, because (a) it's not like we're actually using paper for much and (b) you can just set your computer to whatever.

And 90% of the time professional printers are going to be printing to huge sheets and cutting it down anyway.

I'm one of those fountain pen oddballs to whom paper is very important. A4 and A5 notebooks for me, please.

Same here. Off topic, or I'd discuss my fountain pen collection.

By which you mean “addiction” if my desk is anything to go by.

* Coughs in Urushi *

I once took the time to figure out how much ink I used per page. 1.1 mL of ink from the CON-70 in my Pilot Custom Urushi (FM) translated to 11 pages of writing on A4 paper (~ 350 words per page). Because A5 pages are half the size of A4, I now knew both how many pages of either size notebook it would take me to finish a bottle of ink: ~ 500 A4 or 1000 A5 pages to one bottle of Iroshizuku Shin-Kai.

That's going to take me while, but, due to the paper sizing properties, I have an easy translation of the information.

That was an excellent "drag the topic back to the topic" play. Well done.

Eh, the half-size relationship is hardly an innovation of the A-series of paper: the US uses letter, tabloid/ledger (double-letter-size), and half and quarter letter size. US printed matter and blank books mostly end up in that same set of sizes, because they're all made by cutting and folding the starting stock in half, modulo some trimming of the edges to square them up after binding.

The innovation of the A-series line was using the golden ratio, so that the half-sized paper has the same aspect ratio; half-sized paper always had half the area.

That is among the plausible definitions of "half-sized paper". LOL. But the A-series innovation makes it easier to imagine scaling content/resources because you don't have to "retypeset" in your brain.

But, mostly, my fascination with A-series paper as an American is rooted in my utter disappointment that we refuse to use the metric system (even though every single American does without knowing it).

Most printers sold are letter size by default. Most can accommodate A4 but the defaults need to be changed, you need to arrange new suppliers of office supplies (A4 is less prevalent in the US than Letter size) etc.

I‘d imagine that printer sales are declining in the digital era, which slows down a transition, and most of the ones remaining are at institutions with a lot of inertia (government, medicine)

"Most printers sold are letter size by default."

No, there are many more printers in the rest of the world than in the US and the vast majority are used with or are set to A4 paper.

A4 is the world standard, like it or not. It's only the US and a schizophrenic UK that converted to metric and still doesn't realize it that aren't metric.

I guess I should qualify that with, most printers sold in the US are letter size by default, and that would be true for pretty much any sort of office supply store in the US. Which means that it‘s also the easiest thing to source in the US.

My experience of every modern printer I've seen of Oriental manufacture and that I've used in the US, Europe, Japan and Australia are essentially identical when it comes to paper sizes. All cassettes are large enough to take American Quarto/Letter size and have adjustments/paper restraining guides that easily cover both sizes.

It's possible that there are printers being imported into the US that have nonadjustable cassettes but I've never seen any (not in recent decades anyway). Even decades ago the HP LaserJet II and III would take both sizes. BTW, I still have a a fully functional LJ III bought around 1994.

As far as I'm aware, there are no printer manufacturers that manufacture normal office type printers left in the US, everything now comes from Asia.

Edit: However, in the US reams of letter size are the norm whereas nowadays it's almost impossible to Letter size in any other country. It's been a problem for me because I've had to produce manuals in both paper sizes (depending on which country I was working in at the time). Same with the ring binders which are slightly different sizes not to mention that the US often only uses 3-ring binders whereas everywhere else they're 4-ring and the hole spacings are incompatible.

Which is why literally the second sentence of the comment you responded to is:

> Most can accommodate A4 but the defaults need to be changed, you need to arrange new suppliers of office supplies (A4 is less prevalent in the US than Letter size) etc.

Most Americans doing printing are doing so for Americans, and doing so in an American market that primarily supports Letter size. If you‘re doing localization for other markets, paper site is pretty trivial in the grand scheme of things compared to much larger hurdles like translation.

The location of manufacture ultimately has very little to do with what the consuming market is asking for. Just because most electronic goods are made in China doesn‘t mean we need to switch to Chinese style plugs and sockets.

Nevertheless, the real issue is about the failure of the US to adopt the metric system, and similarly the UK to a lesser extent (UK's already supposed to be metric but it acts as if it isn't). Read my reply to Symbiote.

As I said in a HN post only a few days ago, in most things Australia is a follower not a leader but it got it right with the introduction of the metric system. During which it banned the use of Imperial units (measurement). For example, one couldn't buy a 12-inch rule, only a 30 cm one.

After everyone had gotten used to the change the rules were relaxed and some Imperial stuff could be used but most measurements still had to remain metric - fuel in liters, food in kg etc.

One of the reasons the changeover worked well was that kids learned metric from the outset at achool and if adults didn't want to appear stupid in front of them they had to learn to adjust and they did. In the UK that never happened to the same extent.

Everywhere else four ring binders?

I think not.

The most common standard outside North America is two ring.

For a manual or other documentation supplied in a ring binder, the stronger 4 ring version would be much more common.

The UK has used metric paper for decades, probably the 1970s.

Granted, I accept that. I should have been more succinct.

Let me give you an example (and it's very common, this is but only one instance). The BBC sells/syndicates programs of its health guru Dr Michael Mosley across the globe including here in Australia where I am at present. Regularly, these UK-based programs discuss obesity and weight.

Well, these days, the problem is that no one here knows what pounds are let alone stones and ounces except for a few like me who remember the pre-metric days before the 1970s.

Same goes with TV shows from the UK and the US that mention temperature in Fahrenheit degrees. If you asked the typical person here what 20°C was in Fahrenheit they wouldn't have a clue that it's 68°F.

...And if you were to ask them the difference between an Imperial gallon and a US one, you'd get blank stares to the effect 'what's a gallon and why are there two types?'. Then neither would the majority of those in the UK and US know the fact or that a US 55-gallon oil drum is essentially equivalent to a 44-gallon (Imperial) one. Right, the US has even screwed up the Imperial system.

Moreover, there's an arrogance from those two countries about this. For instance, Mosley's programs are supposedly made to promulgate health and here they're largely deprecated when the local audience cannot put a measure on what he's talking about.

That arrogance is palpable, the BBC doesn't even bother to subtitle the programs with the equivalent amounts in kg or Centigrade and such. And why doesn't Mosley make an effort to mention the matter in his programs? After all, he's been here enough times and even made medical programs here to be fully cognizant of the problem on this side of the planet.

> The change feels imminent

Really? I see zero chance of it. A4, while mathematically nice, offers very little benefit and is an awkward (just a little too large) size to handle. Consistent ratios are of extremely dubious value; if I'm reducing a text by 50%, I'm going to retypeset it anyway. A5 is even more awkward than A4. Too big.

Too big for what? A5 is half the size of A4. But regardless, A5 and A3 both have their uses.

Too long to handle comfortably. I've never liked it. I do make sure to typeset two versions of things I do so Europeans can have something they're familiar with (and their tooling prefers), but I just prefer things a little shorter and a little fatter.

edit: about A5 specifically, I prefer 5½ x 8½, which tends to become 5¼ x 8¼ (even smaller) after trimming the bleeds.

Too long? A4 is shorter than letter by 18mm

"The change feels imminent,"

You have to be joking. The US is already the laughing stock of the world as it's demonstrated repeatedly that it's incapable of going metric. (If you go metric you automatically get A4.)

I recall Kennedy once said that the 'US chose to go to the moon and do other things not because they are easy, but because they are hard'.

Seems many took 'other things' to heart and decided that if things had to be done the hard way then they may as well continue slogging it out with the antiquated brain-muddling Imperial System.

Right, doing 'nothing' the hard way set the US back a decade or two.

Twice in the past century the US changed paper sizes.

During WWII, to save paper, the government mandated that letter size would be one inch shorter, so it was 7 1/2 x 10. This innovation did not survive the war.

Legal documents submitted to court had to be on legal size paper. In Florida, this was prohibited by the end of the 1980's. Land deeds followed thereafter.

Not sure when federal courts jumped to letter paper.

Letter paper is the default for LaTeX. Thank the gods for the KOMA classes.

The British and Commonwealth countries were hardly better with their foolscap and legal sizes, it was a big mess.

The A sizes, A4 etc., and the B sizes for posters and art are significant step forward because of their ISO standardization and widespread adoption

However, from my perspective, it's not perfect, especially so at the 'edges'. For example the width of A7 shirt-pocket size notebooks of the spiral-bound flip-over variety are just too narrow to use comfortably, here the standard breaks down.

Before ISO standardization notebooks of this type were often wider and easier to use, also they were commonly available.

> If you go metric you automatically get A4.

Canada is metric in almost everything it does, but it still uses Letter-size paper.

An excellent example of the spillover effect. I've noticed that whenever I've visit there.

Also to this outsider, that cultural and physical coupling to your southern neighbor is noticeably different in different parts of the country say between Quebec and British Columbia for instance.

Back in my day, I had a CTO that required I | the messages log to the line printer....

Each day I would have to review the log for any security breaches with a highlighter and investigate any attempts to break our system...

Yeah, that sucked. (we were one of the first VOIP people...) ((Quicknet))

>They don't line up nicely with the A4 stuff. They don't go gently in the A4 folders / sleeves / pockets / ring binders (files) / etc.

This statement, and the rest of the post, simply reads "I don't like different". However, the article is about the mathematical benefits of A4, the failures of 8.5x11, and the true benefit of A4 from a paper-size agnostic society.

This article convinced A4 is better (and the entire system) not because it doesn't fit in my folders, but because it makes practical sense.

It has practical implications. I have a file cabinet which is made for A4 paper in landscape. Now, I have some official paperwork from another country that has more the form of a spell scroll and the only way to fit that into my cabinet or binder or wherever is to fold it.

Which is something I would like to avoid on things like birth certificates and such.

I don't think anyone is defending documents that have to be rolled up?

Letter should fit fine into your file cabinet unless it has some really tight margins.

If "legal" size is a problem, then I can understand that better, but that size is just as much of a pain in a letter world as in an A4 world. They made it too long on purpose. They likely would have done the same thing with A4 as a base, if letter didn't exist.

The article sadly misses the root of the An sizes. A0 has an area of 1m^2, setting its dimensions and defining the rest of the sizes. Quite genius!

The B sizes start at B0 with a length on the short side of 1m, then follow the same pattern. The C sizes, often used for envelopes, are defined as the geometric mean between the equivalent A and B size.

As a child of an architect, when I was a kid my dad would bring old A0 drawings home as paper we could draw and paint on the back of. Loved it.

- Edit: it does mention it, I skimmed it too fast…

It mentions A0, the 1sqm area, then goes into paper weights. You might have accidentally skipped that section.

It's pretty handy that 1 A4 sheet at 80gsm weighs 5 grams

(A4 sheet area: 1/(2^4) = 1/16 of a square metre) * (standard paper weight of 80 grams per square metre) = (5 grams per A4 80gsm sheet).

Would have been useful for calculating postage.

A few weeks ago my sister told me of a proposal for some contract that she’d been working on, and it ended up being 1600 pages, mostly double-sided A4, and printed in quadruplicate, and I rapidly worked out in my head, purely from the memory that A0 is 1m², that each subsequent paper size halves the area, and that 80g/m² is a common weight: that that was going to be something like 16kg of dead tree that was probably just going to clog up filing cabinets somewhere and mostly never actually be referred to. If I did this more often I’d remember 5g per sheet, but the mere fact that all this stuff is simple ratios and unit calculations means you can calculate it all from first principles quite easily. It’s really handy.

I'm a teaching assistant, and I use this calculation every time I have to organize a written exam

"so every students needs 11 sheets of paper... times 234 students... times 5 grams... OK I need help to bring everything to the exam building"

> As a child of an architect, when I was a kid my dad would bring old A0 drawings home as paper we could draw and paint on the back of. Loved it.

You brought me memories of being a very small kid drawing on A0 roll scraps bigger than me on the floor of my parents' studio :)

Those cardboard tubes the A0 drawings where stored in were brilliant for building stuff with, and even more fun as a later teenager having parties - stick one end in a fire pit and they become fire cannons, a good 4-5ft of flame out the top…

Also, when it comes to envelopes:

"This means that C4 is slightly larger than A4, and slightly smaller than B4. The practical usage of this is that a letter written on A4 paper fits inside a C4 envelope, and both A4 paper and C4 envelope fits inside a B4 envelope."

https://en.wikipedia.org/wiki/Paper_size#C_series

To fit A4 into a C4 envelope, do you fold in in half or thirds or fourths?

Unfolded

Within this entire system, its all about succesive halvings. So folding into thirds (which is horribly difficult to do) is never needed.

That's not true, the most common envelope at least in Germany is DL for DIN Long [1], which requires folding A4 in thirds and there is a corresponding DIN norm on how to print fold marks to aid the folding in thirds [2]

[1] https://de.m.wikipedia.org/wiki/DIN_lang

[2] https://de.m.wikipedia.org/wiki/Falzmarke

Not only difficult, but prone to being sliced when using a paper opener. Paper folded in four should be placed in the envelope with the fold at the bottom so that it doesn't get cut when slicing the paper at the top of the envelope.

You don't. If you fold it in half you can fit it into a C5 envelope.

I grew up in Europe and I did love the A-n system for its mathematical elegance. But having moved to the US where they use a different size without the halving property I found that I don't really miss it at all in practice and the only benefit I really derived from it was a bit of smug intellectual superiority. I find that a lot of the value of these size systems comes from network effects of many other things in the environment being compatible, such as printers, paper cutters, rulers, etc. With Letter I like that the dimensions are almost whole imperial values (8.5 x 11), while TBH I always found it annoying that A4 had so many significant digits. It has a very technocratic vibe to it - user is not as important as having nice mathematical properties, damnit! :-)

Why would anyone care about "almost whole imperial values"?

The US still uses imperial measurements.

Actually, no. The US gallon (3.785L) is not the same as the imperial gallon (4.546L), a point which made me see red when Canadian opponents to metrication argued that we must keep the gallon because the US is our biggest trading partner.

The real reason Canadians and Brits should have opposed metrification: the transition wasn't ever 100% completed leading to horrifying Frankensystems where Brits buy meat by the kilo but measure their own weight in stone. Or Canadians still measuring train rail distances in miles.

Then just push for full adoption of the system and over time youll get there. Can be slow and sometimes painful but so are a lot of things; "no pain no gain" as they say

You have it backwards. Metrication in Canada stopped halfway because the opponents created such a stink that the government of the time decided to back off, and nobody since has had the courage to seize the nettle. Perhaps in a generation today's schoolkids, educated in metric, will try again.

To rephrase te question: why would somebody be annoyed with the fractional metric size of A-n sizes ?

The answer is probably quite subjective. In my case, when I deal with materials such as wood, cardboard or paper I enjoy immensely to have dimensions that snap to a certain grid. Call it a mental defect if you will. To illustrate further, let me propose a strawman: would you have no preference between the A4 size being: (1) 210.32 x 297.912 or (2) 210x297? Does it not bug you that 210.25 was rounded down to 210?

The US does not use imperial units. Imperial units are those defined in the British Weights and Measures Act of 1824. What the US uses is the US customary system, where units have the same name as the Imperial ones, but not the same values. Now, the US customary units are defined in terms of SI units anyway, just with annoying, non-integer conversion factors.

EVEN BETTER

(where "better" is actually "really annoying")

Yeah I’m struggling to understand the value of that too.

Less the "imperial" part and more the "almost whole"---it would work just as well if the pages were say 20cm by 30cm---but it is very convenient when doing layout (both electronic and physical) that both the content and the margin are "nice round numbers", and the natural divisions are also nice round numbers that you can easily measure with a standard ruler. 1/2" margins all round? Then the area is 7½ by 10. Printing a 2-up booklet? Each page is 5½ by 8½, exactly. If I had to design the size from scratch to optimise this property I'd probably go with 8"×12" (or 20cm×30cm!) but I assume there's some older printshop standard we're inheriting from here.

Not saying A4's not good. Just acknowledging that "nice round numbers" are convenient sometimes. Standards that use US-traditional measurements seem to do better at that for some reason.

This doesn't work at all, let alone just as well.

Half a 20x30 sheet is 15x20, so the ratio has changed from 2:3 to 3:4.

1:sqrt(2) is used to maintain the ratio. The round number is at the start, with the area of A0 being 1m².

> Half a 20x30 sheet is 15x20, so the ratio has changed from 2:3 to 3:4.

So what? The only thing I ever try to print multiple to a sheet is slides, and those are a different shape entirely.

Yes, I get how the A-series paper sizes work, and that they prioritise having all sizes be the same aspect ratio. That has literally nothing to do with what I'm talking about in my post. It turns out that paper "works" for things other than resizing other sheets of paper.

You don't miss it in practice because US society isn't built around it in practice.

There's something great about being able to print something at home on A4, see how it looks, and know that it's going to be exactly the same (no stretching or cutting required) when you go to a print shop for an A1 or A0 print.

And yes there is a lot of legacy network effects around Letter size, which is why the switching costs are very high to make switching impractical.

A move _away_ from paper, to government signed crypto certs and witness logs is the answer.

Then we just need to standardize on A5 as a standard for bills mailed out, since it'll fit inside of everyone's filing cabinets already. A5 for taxes would also be nicer too.

Then get school supplies made in A5 size (easier for kids to carry), and finally after a silent transition period where there's less and less in the US Letter size, we can relegate PC Load Letter to the Office Space movie.

What are witness logs?

A record of transactions (log) witnessed by another party. Like website cert transparency logs. The third party might be a government (in the case of banks they probably already witness this anyway, it's just making it official), banks auditing each other's books, etc.

a specific functional benefit, besides the network effects of standardization, is foldability

you can fold A(n) paper in half to make a brochure or booklet of size A(n+1), for example. it will fit perfectly into any envelope or folder sized to fit A(n+1) pages.

I too moved from Europe to the US and the paper sizes are the worst - have you tried folding it? It doesn’t work.

> almost a whole value

But not a whole value.

That's the thing, though, the folding was never helpful to me even while in Europe; it was a Nice Thing but I never used it in practice. Maybe if I was there now I could take advantage of it for proofing large format prints, like one of the sibling comments pointed out. But even the envelope thing was not helpful - the only envelopes we had were the blue communist ones, the international ones, and you ended up folding the letters at the edges to make it fit.

> But not a whole value.

Right, I said that because one of the dimensions is a half. However in practice those values behave as nice round numbers as well, because in the imperial measure context most things are sized to powers of two, i.e. 1/2, 1/4, 1/8 etc.

I feel like you don’t get to criticise the value of the system if you grow up in a communist country that lacked access to the different sizes of paper and envelopes that make the system useful. Clearly you missed out! Making an A5 booklet from A4 and mailing it is something any print shop I grew up near would do.

No idea what the advantage of a whole unit is supposed to be; nobody is sat around with a ruler measuring A4 cuts. The tolerances for paper manufacturing need to be specified in tiny fractions of a mm either way. As for actual typographers, they don’t use metric units, the size of the paper is not of great concern.

Heh, that's probably a fair point.

I added some more thoughts on the value of whole units in a sibling post. Like I mentioned it's mostly subjective, and has some utility to me when working with paper and measuring cuts. So yes indeed with a ruler, measuring cuts. :-)

I would have expected a communist (i.e. poor) country to have more use for some properties of the paper system:

1. You can easily calculate the weight of that letter without a scale, and stick exactly to the 20g limit (or whatever) for the cheapest postage rate. (I remember doing this in the 1990s for air mail letters to relatives.)

2. You can crush 2, 4 or even 8 normal A4 pages onto a single sheet while photocopying, and save paper/money. Although maybe by the time photocopiers were available in your country, the cost of paper was no longer an issue. (I would press the 2-on-1 or even 4-on-1 button when printing at university, to halve the cost at essentially no inconvenience.)

Your point about childhood really struck a warm note with me. I feel one of the most important and loving things my parents did for me as a child was ensuring a limitless supply of stationery.

Beautiful (in an educational sense and in a visual sense) CGP Grey video on metric paper: https://youtu.be/pUF5esTscZI

Cool animation, as almost always by CGP Grey. Reminds me of the book "Powers of Ten" by Philip and Phylis Morrison, published in 1982 ("Scientific American Books")

Powers of Ten was also a 1977 short film: https://www.youtube.com/watch?v=0fKBhvDjuy0

(Duplicating my own comment from a few months ago.)

In the Director's Commentary (https://www.youtube.com/watch?v=8lyN6Qg8VQ4 ) CGP Grey said that it was directly inspired by the video version of "Powers of Ten".

Glad you liked it!

Are you really CGP Grey? If so, thank you for your high quality videos! (Science) educators like you make YouTube and the internet a better place :)

(Ooh, I had a quick question if you don't mind - how did you get into animating the videos in the beginning? I'm also hoping to make sciencey/educational/technical videos on YouTube but I don't have any animation/software experience. Right now I'm just planning to draw static images/diagrams on my iPad and use that for the video, like a slideshow.)

He goes into it in an older comment in his history: https://news.ycombinator.com/threads?id=Orthanc

Yes it's really me -- I don't often comment on hacker news, but it was just funny to come across my own video here.

Just taking a second to appreciate you and your work. I have one of the first ever Theme System Journals. While I've grown older and now no longer watch your videos as religiously as before, I do still follow along Cortex.

I was a patron for Hello Internet. Though I doubt it will, I hope you guys can one day bring it back. So many fond memories :)

Thank you for your hard work and almost-always insightful remarks!

What happened to HI though? They seemingly stopped doing it without any reason and I really liked it. Thankfully Cortex is a lot like HI and I enjoy it a lot.

This question is raised every time Grey or Brady pop up anywhere. Although it's understandable (Hello Internet was great!), I've become a lot more sympathetic after watching a Patrick Rothfuss video about how it dehumanizing it feels to constantly be asked nothing besides when Famous Thing is coming back:

https://www.youtube.com/watch?v=qtlYvNB6PZE

I wish HN had a feature to follow or anotate users. Not the first time I meet someone interesting I know from another space here on HN. However, without such feature, I shall forget the username.

Create a bookmark category for HN users you want to follow, and bookmark their comment pages.

You can use Hacker News RSS [0] and subscribe to a user's feed [1] via https://hnrss.org/user?id=USERNAME

[0]: https://hnrss.github.io/

[1]: https://hnrss.github.io/#user-feeds

I figured since for Reddit this functionality is provided by RES, for HN it should be HNES so I searched "hacker news enhancement suite" and found this [1] which does list "Ability to tag users" among its features.

[1]: https://chrome.google.com/webstore/detail/hacker-news-enhanc...

That went a very different direction than I expected. Thanks for sharing :)

That video kinda lost the thread of what it was supposed to be about, it went from a cool video about paper (which admittedly is no easy task) to a generic “things are small but also things are big”

I dont think the video is really about the paper, it's just a hook.

There is a secondary series, B, in which the base size, B0, -instead of being defined for its area of 1 square meter as is A0- is defined to be 1 meter wide. A series is then 1, 1/2, 1/4, etc square meters, while B is 1, 1/2, 1/4, etc meters wide.

It's not as common as the A series but it's used occasionally and it offers intermediate sizes between those of the A series.

And then you have the C series. Mainly envelopes that are mean between A and B thus fitting the A reasonably inside.

Yes, but that is really rarely used -at least around here-. Most envelopes nowadays have opted for different factors. Usually you fold an A4 in thirds on the longer side and use an 110x220 envelope.

Nearly all letters I get are in C5 envelopes, i.e. A4 folded in half. But Denmark is so electronic that "nearly all" is about one a month.

Folding in thirds isn't worth the bother when I post things so infrequently.

Choosing a large British supermarket, they have C4, C5 and C6 sizes, plus DL (A4 in thirds) which are cheapest: https://www.tesco.com/groceries/en-GB/search?query=envelopes

Same in Switzerland. Almost all letters are A4 folded in half inside a C5 envelope.

> The dimensions of DL [size] are 110 x 220 mm (4⅓" x 8⅔") and as such the DL envelope will hold an A4 sheet of paper folded into 3 equal sections parallel to its shortest sides.

* https://www.papersizes.org/c-envelope-sizes.htm

* https://www.youtube.com/watch?v=DmBvP0KOZP0

In Poland some school supplies use B series. Like notebooks and coloured paper for a&c.

Similarly in Britain, typical notebooks (especially at school) use the B sizes. I think it's probably common across Europe.

It means you can paste an A5 sheet handed out by the teacher into your B5 notebook, leaving a reasonable margin around it. Or you can fold an A4 sheet in half, and paste that in.

Yes. It's common in most of Europe afaik. B5 is a quite nice size for notebooks.

B5 is very common in Japanese stationary, in particular those silky-smooth notebooks.

I think that B width goes 1, √2/2, 1/2, √2/4, 1/4, √2/8

> A series is then 1, 1/2, 1/4, etc square meters, while B is 1, 1/2, 1/4, etc meters wide.

It’s folded in alternating direction so it doesn’t go down as fast. It’s 1m wide, then 1m long, then 50cm wide, 50cm long, etc.

You're absolutely right. Thanks.

A map of paper size usage throughout the world: https://vividmaps.com/paper-sizes-world-map/

I wondered whether the fjords use US letter, at first. ;)

I wish it was like this. Some countries have two standardized sizes where certain documents are in "US letter" and others in "US legal" format depending on the institution.

> Some countries have two standardized sizes where certain documents are in "US letter" and others in "US legal" format depending on the institution.

To be fair it used to be even worse, as the fed used to use demitab (8x10.5).

> A4 is 1/24 m2, so a sheet of 80gsm paper in A4 size weighs exactly 80/24 or 5g.

I hope they were more precise with the maps than they were with the calculations (A4 is 1/16 m2, and then 80/16=5). :)

The international paper size standard is ISO 216. It is based on the German DIN 476 standard for paper sizes. This standard was designed by the German engineer and mathematician Walter Porstmann in 1922.

Cf https://de.wikipedia.org/wiki/Walter_Porstmann

The ISO will charge you 58 CHF (equivalent to 59 USD) to read the standard.

https://www.iso.org/standard/36631.html

I can't help but feel a perverse pleasure that the US refuses to switch.

If only the US didn't use C because it costs 198 CHF to read the standard.

I pity the fool still programming in ANSI C

And ANSI will charge you $68 [1] to read the US paper sizes standard [2].

[1] https://webstore.ansi.org/Standards/ASME/ASMEY142020

[2] https://en.wikipedia.org/wiki/ANSI/ASME_Y14.1

Pfft, have you tried accessing any standard here? (ASME, IEEE, etc.)

That perverse pleasure must be masochism.

To be fair, charging for standards like these is pretty silly when the goal should be to have them adopted as widely and correctly as possible. Standards organizations need funding but as something that benefits pretty much everyone there is no reason not to fund them from taxes. Doubly so with digital distribution where the marginal cost of someone viewing a standard is ~0.

And it seems like pocket change too. How many companies are going to pay to access a standard? Thousands? Still not a lot of money.

The fact A-series has a sqrt(2) radio is obviously neat on its own, but does it save material, or have much benefit in general in practice?

My (very limited) experience in printing seems to be

1) they still trim tons of bleed regardless;

2) the fact you can cut A3 into two A4 etc. is great, but doesn't really matter when 99% of the printing paper will be just one size (A4) anyway?

3) Lots of magazines and books use non-standard sizes.

Disclaimer: I'm from a metric country. This is a genuine question, not in anyway trying to make excuses for The US' letter size or what not.

It saves a lot of resources on the supply side, not on the consumption side. So it does lead to lower prices for consumers, just indirectly.

Sorry I wasn't clear. My point is that, since majority of the demand is A4/letter, in letter's case, they can still use certain size of big rectangular paper and cut them into letter. The fact these larger paper can't be cut into other shapes doesn't really matter on supply side because they're not going to.

If they need some other odd shaped papers, just like metric B-series, they do that separately.

Mass printing isn’t done on A4 directly. It’s done on printing machines of a larger size and then cut and folded as needed.

I get that, I'm saying that precisely will make the size of a single page (A4 or letter) or its ratio irrelevant in practice.

The benefit for A* and B* sizes is that you can buy a roll of A0 or B0 and then print directly and then you can cut to any A* of B* without any offcuts.

For documents that need bleed to edge you have RA* and SRA* sizes.

The best advantage, which you might not realize until you need to use US sizes, is the easy scaling up and down.

You can put an A3 sheet on a photocopier and press the "A3→A4" button and have the original perfectly scaled onto a single A4 sheet, or vice-versa. There's usually a button that does A4→2 A5, so you get two half-size copies on the A4 paper, which you can cut into A5 sheets. (In my school, university and workplace experience, it's very common for A3 paper to be loaded in photocopiers and some printers.)

Equally, you can design something in A4 size on the computer, then print it on A3 paper without any changes. Then send it to the print shop for an A1 print, still with no changes.

An envelope that fits A5 paper will fit once-folded A4 paper perfectly.

(Magazines people expect to be photocopied, like scientific journals, are often A4 sized.)

> Equally, you can design something in A4 size on the computer, then print it on A3 paper without any changes. Then send it to the print shop for an A1 print, still with no changes.

My equivalent experience in academia is that you can design posters and print drafts on A4 sheets to see how they look and be confident that they won't be butchered when put on A0 at the print shop.

> 2) the fact you can cut A3 into two A4 etc. is great, but doesn't really matter when 99% of the printing paper will be just one size (A4) anyway?

This is more for the manufacturing side. At the factory they really only have to make A0 paper that can then be cut to any other A size without any waste. You can't do this if the paper sizes are not related which is the case with North American sizes.

Also the fact that you can fold a A4 into A5 (what is used for letters here) with a single fold is really neat.

FWIW I found it very useful when I was going to university, and broke, and needed to print articles and or books online with the minimum number of sheets, and relying on booklet printing[1] to put up to 4 a4 pages (back and front) on a a5 "book"

https://www.printingcenterusa.com/blog/how-to-arrange-pages-...

For digital printing this standard is very important and handy especially at home/work.

1. Not really - if you go to professional digital printer they have other formats +, RA and SRA (A3+, RA3, SRA3) that are slightly bigger to accommodate for bleed.

2. It matters if you want to make saddle stitched binding yourself - you fold A3 and get A4 booklets.

3. If you make bigger runs of anything at professional (offset) printer the standard sizes don't matter that much because you print on big sheets (like B0) that get cut (often multiple different jobs on same sheets). So it's about waste (not printed space that gets trimmed). But the paper waste really matters only in very big runs 5k+. Whats more expensive are offset printer plates that need to be made.

So yes the magazines/books can be any size but the space on rest of the plate/paper will be filled as much as possible.

> they have other formats +, RA and SRA (A3+, RA3, SRA3)

This is what I'm trying to say though, the whole ratio thing or 1m^2 area thing will be irrelevant, isn't it?

You end up with A# format. Thats still valuable. For example envelopes and most bags expect A4. Also you can still use the paper gsm for example to calculate the weight when its in A#.

Advantages of this system are pretty hidden and subtle but when you notice it helped you then you are glad somebody put lots of thought into it.

What would be better alternative? Make it random?

A lot of printshops lease their printers and pay per page.

When they print A4 for customers, they actually print A3 and cut it in half, saving half the printing cost.

That's no different than the US, where your 8 1/2" x 11" often starts as an 11" x 17"

The most important practical advantage -- one reason I like the A4 / A5 family -- is simply that proportions are preserved when you print two pages on one sheet and fold over. Adjacent to that is the advantage that there are a family of sheets to work with in practical sizes -- A5, A6 and A7 are all quite useful -- and they bear a certain logical relationship to one another that is easy to work out, in terms of how many of one size fit on another size.

Here is another good explainer which might be a bit easier to parse: https://unsharpen.com/paper-sizes/

Minor side point, I’ve never seen an x written as )( but always as / and then \ (or vice versa). I wonder if this is a regional thing ir just one person’s preference.

x is usually written 𝑥 in mathematics (including handwriting) to distinguish it from ×.

I was taught the ")(" way at primary school.

Just because you use it doesn't make it in any way 'usual'. Just because you learned it in some school doesn't make it non-regional. Also, your own example "𝑥" is decidedly not of the )( form, but of the × form.

You might have read my comment more carefully before resorting to a snarky reply.

Sorry, I mistakenly thought you replied to the post you posted your post under. My bad.

Doing an image search for "handwritten algebra" I find quite a few examples of ")(".

"I was taught the ")(" way at primary school" is a perfectly reasonable response to your question, which wondered whether it was just one person's preference. That answer tells you it isn't.

Nowhere did the reply suggest it wasn't regional, nor, for that matter, that "/ \" isn't regional. Both are presumably regional, but whether one is more common requires a fair bit of work to answer.

In Lateinische Ausgangsschrift the )( form is commonly used. Which is the most common type of cursive taught in German schools nowadays.

The article makes these 2 contradictory claims:

> I can tell you now it is precisely 210mm by 297mm

> So the only ratio that has this important property is the square root of 2, famously – and ironically in this case – not a ratio

I suspect either:

- A4 paper is not precisely 210x297 mm, or

- the precision of the ratio has been sacrificed in order to allow integer numbers; but if we're willing to make that sacrifice, why not round up to 212x300 mm? and then we can have the nice round number that the classmate wanted in the first place, with a bonus that both dimensions are even-numbered so can be halved with mm-graduated rulers.

A4 paper is precisely 210x297mm (according to the standard), so the aspect ratio deviates from 1:sqrt(2) a little. Following that aspect ratio, the size would be 210x296.985..mm, so the rounding is really very slight.

How exactly is it defined in the standard? Is there a formula? Or just a list of sizes for A0, A1, etc.?

I wanted to read the standard myself, but CHF 58 is a bit too much:

https://www.iso.org/standard/36631.html

   y : x = √2 : 1 = 1,414

http://www.ikserang.com/qa/ISO_PAPER_BOARD/standards/en/iso_...

This seems to be a sample containing the relevant parts. https://cdn.standards.iteh.ai/samples/36631/c0883203ea25445c...

I'd guess because 210x297 is closer to 1/16 of a m^2 than 212x300 is.

> why not round up to 212x300 mm?

Because the A standard's baseline is A0 which has exactly 1m^2 area. So that nice rounding did happen, just at the baseline scale, and on area. The B series is a tad larger, B0 happens to exactly be 1,000 × 1,414 mm.

Which also makes it quite nice to know how much a sheet of paper weighs. At 80 g/m² you'll get 5 g (80 / 2⁴) for A4. Handy for quickly determining how much postage to put on an envelope based on how many pages you put inside it.

I love describing 41,4% as tad. Then again I suppose concept of comparing areas is bit harder.

If you change the size of A4 you have to change the size of all the other A- sizes too.

A0 is anchored at 1 metre squared, so everything else follows from that.

1) The integer number is A0 being 1 square meter of area.

2) Rounding to whole centimeters, or an even number of millimeters, is too coarse.

A0 has an area of 1 m² and the long edge is sqrt(2) of the short one. This fixes the edge lengths to 841 mm x 1189 mm (rounded to the nearest mm). A4 is obtained by halving A0 four times.

I was wondering that too! I got to the end and still no explanation of 210×297mm.

Well, it turns out that it's based on the fact that A0 is defined as having an area of ~1m², then each subsequent size halves the area. So A4 has dimensions that give an aspect ratio √2 and an area of ~1/16m².

    A0: 1,189 mm × 841 mm = 999,949mm² ≈ 1m²
    ...
    A4: 297 mm × 210 mm = 62,370mm² ≈ 1/16m²

See https://en.wikipedia.org/wiki/Paper_size#A_series :

"The A0 base size is defined as having an area of 1 m² ... rounded to the nearest millimetre, 1,189 mm × 841 mm".

That's a beautifully short definition, I think.

"Base-size has 1sqm area. Halving does not change ratio of the sides."

You may have skimmed over this bit in the article then:

"the international A-size system now starts with A0 paper, with sides in the correct 2‾√ ratio, but with exactly 1m2 of area, or as near as you can get with whole millimetre side lengths (1189mm 841mm, to be precise). Then folding or cutting it a few times until it is conveniently desk/folder sized gets you to A4, hence the ‘4’ bit in the name."

Yes I did! Thanks for pointing it out and very politely too. :)

"Unnecessary accuracy is technical incompetence" - Engineering saying. You need accuracy to serve some purpose. Too much is inefficient and expensive. Too little does not work. 212x300 would not serve the purpose. Try folding and you see how bad it is.

Typically, paper comes in A0 size (841x1188mm) which is then cut in half X times to get the desired paper size, which is either eyeballed against a ruler, or measured by laser.

If the operator is skilled, or the machine is well-calibrated most A4 paper is therefore exactly 297mm tall, and 210.25mm wide (so slightly wider than the standard)

I guess the second claim is referring to the fact that the square root of 2 is an irrational number, so it can’t be expressed as a ratio of integers anyway.

I love this little fact but stating, "It is possibly one of the greatest innovations of the 18th century" is ridiculous hyperbole.

Or maybe the 18th century was severely lacking in innovations.

Surely a joke, given that it can be argued that even the steam engine wasn't the most impactful innovation of the century.

True, obviously the most impactful innovation of the 19th century was Taylorism.

I can't not share this excellent video on the subject by CGP Grey on "metric paper":

https://www.youtube.com/watch?v=pUF5esTscZI

It's interesting that the human scale is (logarithmically) in the middle between the plank distance and the size of the observable universe.

I hope we will use the A* family of paper sizes in the USA more widely. Many excellent notebooks, notepads, &c are available from Germany, Japan, France and England in the A* family of sizes, and they all work with the corresponding envelopes. There is so much paper correspondence -- in the form of utility bills, government notices, packing lists, and many other things -- that could fit on A5, which is a handy size for many things; and now manufactured in great quantities all over the world.

When I lived in Japan and worked with ISO paper, it made me realize what we in North America are missing out on. I wish it were more widely available because I'd buy it.

A0 ≈ 1 m² was new to me but makes perfect sense. Imagine a world where the makers of USB used a similarly elegant naming convention.

A1 should be ≈1m for it to be elegant.

A0 = 0 folds of 1m². A1 = 1 fold, ...

Though maybe we could have A3.1 Gen 2x2 for thick blue paper with glossy texture folded 4 times but 2 of those folds weren't down the middle.

Oh I completely get that 0 = 0 folds, but if we are comparing square meters then A1 is 1 square meter.

It depends on your point of view on what you are comparing.

    A0 area = 0.5^0 = 1 m^2
    A1 area = 0.5^1 = 0.5 m^2
    A2 area = 0.5^2 = 0.25 m^2
    A3 area = 0.5^3 = 0.125 m^2

If it was your way

    A1 area = 1 m^2
    A2 area = 0.5 = 0.5 ^ (2-1) m^2 
    A3 area = 0.25 = 0.5 ^ (3-1) m^2

Why shift it one way just to shift it the other way in the formula?

If you want to fit the area into the name you can think of it as

A0 = 1/(2^0) m^2

A1 = 1/(2^1) m^2

A2 = 1/(2^2) m^2

And so on

(EDIT for formatting and also to observe a sibling post to mine is making the same point)

No, because 2⁰ = 1.

Paper weight is measure in grammes per square metre. 80gsm is typical for ordinary paper.

  A0 = 2⁰ m² = 1 m² → 80g
  A1 = 2¯¹ m² = 0.5 m² → 40g
    ...
  A4 = 2¯⁴ m² = 0.0625 m² → 5g

(Fixed typo, thanks.)

Small nit: A1 should be half the mass of A0 (40g in your example).

I had a major epiphany deriving this myself as a teenager, because it was the first time I used algebra to calculate something "real". The equation was trivial, but the principle of mathematical modelling struck me like lightning. In an instant the world felt more comprehensible and tractable, I suddenly felt like Neo seeing the Matrix.

Sure there is math behind it, I was at a paper factory once, I asked them about the whole A0 and so forth sizing, I was told in prefect german and translated that originally they made 1M^2 sheet (alle) and they would them take those and cut them by halfs, so when an order came in, it would read Alle/2 Alle/4 a so forth since they would then say take this pile to A, A2 and A4 cutting station. Who knows, but that is what the Aschaffenburg guide tolde me back in 1998, been telling everyone that story since… :/

So A1 is half of 'Alle', so Alle/2, no? A2 is Alle/4 and so on, making A4 Alle/16?

Maybe it's the number of levels down the tree of cuts. With one cut, it's A1; cut the results one more time to get A2; cut the results one more time to get A3; &c.

While I really appreciate the fact that you can split an A4 sheet and get two A5 sheets. Even as a European, I always felt like the American letter format feels 'nicer'. I feel like the letter format's ratio works better for taking notes in a notebook or browsing through printed pages -- less tall, but wider than A4.

Anyone made a similar experience?

I do think A4 is too wide for note taking, I almost always use two columns.

so A5?

Not necessarily, if they’re talking about splitting it vertically, not horizontally.

Yes.

I agree. The American reluctance to metric units is strange and I appreciate the mathematical elegance of ISO paper sizes, but letter paper just feels more pleasant on the eyes than A4.

> American reluctance to metric units

Reluctance is too strong a word. In the US we use metric for quite a lot of measurements. Frequently things are labeled in both metric and imperial. What we have is ambivalence. Folks from countries with more metric adoption care way, way more about the US using imperial than anyone in the US does.

I dunno about ambivalent. Tell a US person it's 30° outside in the summer and at best they'll give you a blank stare, at worst they'll say "well no it's gotta be warmer than that out." They don't learn it, so no one uses it. If schools taught it then it might catch on. The food labeling stuff is for regulatory reasons, the only metric units US people actually use are liters for beverages.

Beautiful! One more thing to add re A4 vs letter size: A4 is also a better approximation of the 'golden ratio', so supposedly more aesthetically pleasing (though neither is a particularly good approximation, which shouldn't surprise since A4 is an approximation of sqrt(2) not (1+sqrt(5))/2).

I cannot believe no one has posted Markus Kuhn's excellent page on the subject, first appearing in 1996:

https://www.cl.cam.ac.uk/~mgk25/iso-paper.html

It never occurred to me that these same sizes trickle all the way down to passports, IDs and business cards

A4 is metric paper https://www.youtube.com/watch?v=pUF5esTscZI

If you moved from Europe to the US (or vice versa), I'm curious what your thoughts are on using A4 vs US letter? And I mean once you were settled and transitioned to using the other standard, did you find yourself thinking one was better than the other?

Another way of asking this is, if you could magically make it so that everyone had been using and today used one of the two (A4 or US letter), would it matter to you?

> A4 vs US letter

I (European) spent some time in the US in the past and, while I understand why many people prefer A4, I found one major advantage of the US letter format: It is, like so many things in America, bigger.

Very useful if you have to write down equations!

It's slightly wider (6mm) but shorter (18mm), not really "bigger". In terms of surface area it's a bit smaller.

It's only 6mm wider than A4, but 18mm shorter (about 3/4 inch)

    A4      210mm x 297mm
    Letter  216mm x 279mm

You're absolutely right, it is shorter – for some reason my memories just skipped that part. Maybe because the width is the most relevant when writing down long equations. :)

when I see text on US letter, I tend to struggle reading it fast. This is because I find it hard to find the next line after I read to the end of a line. I think there is an optimal line width that allows the eyes to flow from line to line, and documents in the US letter format does seem to regular exceed that.

Of course this is not intrinsically the fault of the paper size. The lines could just be narrower. But then you get a massive margin, which is often not what you want for a /letter/. At least not one printed on 10pt or 12pt. Once you put notes in the margins, or double column layout, US letter might be superior. Maybe also for typed letters as the words tend to be wider in that case.

I am curious if people experience the same, or potentially the other way around.

I'm American and started using A4 because good fountain pen paper is usually A4, A5, etc.

I eventually found that I like the A4 size better than US Letter. US Letter seems unnecessarily wide for most writing.

I’ve done this both ways a few times, and still bounce between Europe and the US a lot. Once I got used to A4 et al I found it maddening that the other sizes are missing in the US.

A4 vs Letter is no big deal, IMO, with modern printer drivers and PDFs and so on.

But once you start making regular use of A5 and A3, it’s hard to adjust to their absence.

However, the DIN sizes are not the only standard sizes in Europe! There are also (de facto?) sizes for art paper, canvas board, and stretched canvas.

For example, 30x40cm is a standard size for painters, and A3 (almost but not quite the same) is only really used for drawing… and sometimes for prints, depending on technology.

On the US side, 9x12in is a standard size for both drawing and watercolor. And it fits exactly zero frames you can buy off the shelf in Europe. But at least 16x20in is almost 40x50cm! That’s been a lifesaver.

Just today I was pleased to realize that my “weird” sized Chinese watercolor paper — Baohong, good stuff - is within a few mm of A5. Because I’ll take any standard at this point.

Yeah, the other sizes are great -- I have small assortment of A* paper at home, now, sourced from various countries.

I moved from a metric country to Canada 25 years ago. Although Canada is technically metric, pounds, and feet still abound. It sometimes feels like litres and km are the only metric units actually used here.

Of all the European measurements, the one I miss most here is the paper size. I still struggle with the scaling mess that is US paper sizes, and long for the elegance of the A, B and C series.

For modern typeset documents it’s a close call but I’d say that A4 has a slight edge in that it’s longer and the extra width of US Letter in practice just means wider margins.

But it’s when you start folding and mailing the paper that the A* system really shines, US system is maddeningly frustrating.

Are there fields (architects, engineers?) that take advantage of the the technical pen scaling? Or scanning software that is aware of the pen/paper ratios? This seems like a great way to have some consistency in analog/digital conversions. It would be nice to have 10 years of digitized notes that all have consistent sizing after scanning.

Architects and engineers certainly used to. Most engineering drawings are printed now, but presumably occasional modifications are still made by hand.

In another comment you mentioned easy scaling in a photocopier. And cylinder714 linked to a description of iso-paper that mentions an ISO (ISO 9175-1) for pens.

Is there a term or place to search for pens sets that scale with A*/B* paper? Using the ISO or "technical pen" doesn't return obvious matches (from my US based search at least).

I searched "ISO drafting pens" and had several results, although none from the US or Canada. Wikipedia lists some manufacturers, and here are some online shops from my first couple of pages of results.

I've never used the steel nibbed pens. My grandfather was a draughtsman, and had a complete set, but as I understood it (age 10-ish) they were delicate and needed to be used carefully. I wouldn't buy a complete set on a whim :-)

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

https://www.rotring.com/pens-pencils/technical-pens/isograph...

https://www.staedtler.com/intl/en/products/technical-drawing...

https://draftex.com.au/collection/pens-markers-inks/technica...

https://www.faber-castell.eu/products/TechnicalDrawingPenTG1...

(There were also Indian websites, so I'll bet there's China/Aliexpress too.)

Wonderful, ISO-128 is exactly it and the wiki explains it perfectly. This seems like a fantastic sizing for pen sets.

The 0.10, 0.13, 0.18, 0.25, 0.35, 0.50, 0.70, 1.0, 1.4, and 2.0 scale with √2. I couldn't tell if other sets were just rounding or dropping the hundredths place. The rotring and staedtler both offer sets in those increments. I suppose this is just common knowledge to those who need it.

The article never mentions why folding in half is a good thing. It is, of course, but why half, and not fifths?

The reason is that two is a good factor to work with. Multiplying and dividing by two is more common than by five in a lot of domains. Three is pretty useful also.

But the metric system is based on ten, which has factors two and five. Five is not such a great factor and often creates awkward numbers when dividing by two or three.

The US measurement system, while inconsistent and arbitrary in many ways, but handles factors of two a lot better. Two cups in a pint, two pints in a quart, four quarts in a gallon.

Better would be to have a consistent measurement system in base 12. Two twos and a three are a nice set of factors to work with. And twelve is still a nice "order of magnitude" that gives a good sense of scale.

When it comes to distances, feet are actually pretty good in this regard. Degrees and time are base 60, which includes an extra five factor, so I guess it's combining all of them.

The non-US world is smug about A4 and the metric system, but the very reasons that A4 is good shows why the metric system is not quite as brilliant as people like to think it is.

(Obviously standardization and consistency have value, too. The metric system is good in that regard.)

all seems more complicated then just dropping down a unit in metric and doing whatever maths you need, without dealing won’t fractions or weird units.

I agree with you, but think 16 would be a better base than 12 as it's binary reducible all the way down. It doesn't have a factor of three, which can be useful, but being able to natively understand and do math in a hex base would be such a boon, especially in the computer era.

The Babylonians base 60 was quite a practical decision we partially inherited, but the metric 10 and Aztec 20 were probably just cavemen looking at their fingers (and toes).

If you use your thumb to index the interphalangeal joints of your hand, you also get 16 which is super slick. A4 is a nice standard, but we really missed out on realizing base 16 metric.

Can't divide 16 by 3 though; the nice thing about 12 is that you get nice natural numbers for many common divisors:

  >>> 12/2, 12/3, 12/4, 12/5, 12/6, 12/7, 12/8
  (6.0, 4.0, 3.0, 2.4, 2.0, 1.7142857142857142, 1.5)

  >>> 16/2, 16/3, 16/4, 16/5, 16/6, 16/7, 16/8
  (8.0, 5.333333333333333, 4.0, 3.2, 2.6666666666666665, 2.2857142857142856, 2.0)

With base-12, only 7 is awkward (and that's probably okay as it's not that common) and the non-natural numbers of 2.4 and 1.5 when dividing by 5 and 8 are still fairly easy to deal with. Dividing by the common figures of 2, 3, and 4 gives nice numbers.

Base-16 has the "infinite number problem" for 3 and 6 that base-10 has, and only 2, 4, and 8 give natural numbers.

This is probably why there are 12 months and why people used "a dozen" for a long time.

Sure and I agree with you, except base 16 is binary reducible all the way down which isn't a small thing.

The Imperial or US standard systems of measure rounded the horses on halving in an awkward way because halving is intuitive. 1/2, 1/8, 1/16, 1/32 of an inch etc. and it's proven very useful. Splitting a meter into ten is less useful than splitting it in half and that half into half.

Base ten doesn't half indefinitely across units bases. 1000cm, 500cm, 125cm, 62.5cm, 31.25, 15.625, 7.8125, 3.90625, 1.953125, 0.9765625...

4096cm, 2048cm, 1024cm, 512cm, 256, 128, 64, 32, 16, 8, 4, 2, 1 (which of course looks a lot better in base 16 notation)

1000, 800, 400, 200, 100, 80, 40, 20, 10, 8, 4, 2, 1

We could have had the best of both worlds. When SI was getting standardized there was a proposal for extra glyphs for base 12 and 16 that would have obviated our overloading of A-F too. Measuring in 1/256 of an inch would have been crazy simple while also getting the other metric goodies, IMO.

We're already long past the point where doing math in hex (or binary) is something that an average software engineer is likely to face. And outside of the industry, who ever cared?

There's lots of practical implications to measuring in halfs indefinitely. See my response to the sister comment. Hex exists because binary switches are simple to manufacture and simple to reason about, but we've been halving measures since time immemorial and will continue to do so, even if our systems make it a bit difficult.

Binary search trees aren't just base two because we liked the number. Base ten, on the other hand, is just a number we picked and it happens to check a few boxes too.

Sheets of paper are not used to measure or calculate things, unlike the metric system.

> Better would be to have a consistent measurement system in base 12.

Or a system in base 60, where 12 and 5 are alternating:

- 12 hairs = 1 graph square - 5 graph squares = 1 inch - 12 inches = 1 foot - 5 feet = 1 manlet - 12 manlets = 1 stone's throw - 5 stone's throws = 1 dash

And so on

It’s a physical good. The reason is that it’s easy to fold in half and it offers a good enough granularity of size.

Also having a measuring system in base 10 when you use base 10 for notation will always be more handy to calculate even it has less divisors. Your comment is the kind of comment which can only be made by someone who has never used metric.

I agree base-12 would be better (having 12 months is nice) in principle, but in practice I found it rarely to be an issue and I've paid special attention to it since I first heard this argument a few years ago because it sounded convincing at first.

Stuff like easily using fractions (1.65m, and what's halfway between 6"4' and 6"5'?), division of things with fraction (what's half of 6"4'?), and converting from cm to m is much more common. So while metric does indeed make some things harder, it makes many common things easier. Overall, it seems like a fair trade-off.

It would be great to have a consistent measurement system in base-12 on top of base-12 numbers. But without this latter part, you end up with base-12 units computed in base-10 numbers, which creates more mess than having a few extra divisors remove.

And, unfortunately, we're way too committed to base-10 to change it now. So metric it is.

> 80 gsm (grams per square metre) paper at A0 size weighs precisely 80g. A4 paper at that density therefore weighs 5g since it’s been halved 4 times

So when they mark the gsm number onto a ream of A4 sheets, is 80 the gsm of A0 or A4?

Excellent article by the way. Thank you.

Both. A 80 gsm ( = grams per square meter)A4 sheet has the same density as a 80 gsm A0 sheet (80 gsm= 80 gsm) but only 1/16th its weight (5g = 1/16×80g) since it only has 1/16th its area.

> So when they mark the gsm number onto a ream of A4 sheets, is 80 the gsm of A0 or A4?

It's the same thing, since it's the grams per square meter. A0 is 1sqm by definition, and if you tile A4s until you have 1sqm of it, you get A0 (at least if you double through the small side every time: A4 -> A3 -> A2 -> A1 -> A0)

The same size relationship is for Euro stacking containers: https://en.wikipedia.org/wiki/Euro_container

US legal is way better suited for reading. Or the comic-book format

The metric system is such a beauty, that it's shocking that is not used everywhere. The fact that a liter of water has a relation with the size of the paper we use is just poetry.

The three holdouts being the US, Myanmar and Liberia: https://cdn.statcdn.com/Infographic/images/normal/18300.jpeg

Why does everyone forget the UK and Canada?

The picture acknowledges both

Not Canada though, which is definitely more imperial than the UK.

>In Canada, Australia, India and some other former Commonwealth countries vital statistics, living and commercial spaces, oven temperatures and recipe measurements might still be imperial.

The UK has adopted the metric system for most purposes, except for a few high-profile holdouts (speed limits and beer measures).

And area. It's not uncommon to see land sold by the acre or apartments by the square foot.

Rare to see square foot only, but 108 square foot sounds bigger than 10 square meters, 2.7 acres sounds bigger than 1.1 hectares, so obviously salesmen are going to include those numbers.

Filling up on fuel in litres and then using miles per (Imperial) gallon to measure fuel efficiency is wonderfully convoluted.

Indeed. I suspect the driving and oil lobbies are keen to keep it that way, to help obscure the cost per unit distance and thus keep us all driving as far and burning as much gas/petrol/diesel as possible.

Miles per litre would be fine, even km per litre, but the metric way of measuring flips it over so bigger is worse rather than better, so it doesn’t catch on

The numbers don’t work out too, “litres per 100km”. Why not millilitres per km (or litres per gigametre)

I drive X miles (or X km), I then fill up with Y litres (or Y gallons)

If I put 40 litres in my car and do 16 km per litre that’s 640km of range, simple calculation of 40x16

If I need to travel 260km at 20km/litre I need to but 260/20 litres or about 13 litres.

If I put 40 litres in my 3.6 litre per 100 km my range is 40/3.6 = 11 x 100 = 1100km.

If I need to do 260km at 3.6l/100km I need to do 260/100 = 2.6, times 3.6 = 9 litres.

With the “metric” way you need to do two calculations.

if you insist on using volume per length, I’d personally prefer 36ml/km, then I know I need 36x260 ml of fuel to go 260km, or my 40,000ml tank will take me 40000/36 = 1100km.

> The numbers don’t work out too, “litres per 100km”. Why not millilitres per km (or litres per gigametre)

> I drive X miles (or X km), I then fill up with Y litres (or Y gallons)

This isn't what most use the liters per 100km for though. People just fill up whenever the light on the car tells them to. Mainly the number is used to compare cars when buying a new one. Some keep track of the actual consumption to notice if something is wrong with their car (just write down the current number on the odometer and how many liters you put in on some paper/app/whatever. you can do the actual calculations later)

At least this has been my experience here in Finland.

> If I need to travel 260km at 20km/litre I need to but 260/20 litres or about 13 litres.

> With the “metric” way you need to do two calculations.

That's really an absurd way of looking at it, because one of those calculations is a division or multiplication by 100, and 100km happens to be a typical distance someone might be interested into finding fuel efficiency.

So the answer to me is an immediate mental computation, 2.6 x 5l = 13, you never ever need to compute consumption per km, express things in ml etc.

Your own "easy" examples look to me very intuitive and convoluted, so I guess the systems are 100% comparable, the only difference is the power of habit.

I dont think that's true. I see imperial much more than metric.

Measures are much more common in inches, foot and miles than metric. Volumes are much more common in cups, gallons, pints than metric. Weights are more common in pounds and ounces than metric.

That's in almost all domains, not just "a few high-profile holdouts" (even cooking, where it kills me that quantities of solids are in "cups" rather than grams...)

> Measures are much more common in inches, foot and miles than metric.

I think this is partially true, particularly with the older generation. People often talk about their height in feet and inches, and their weight in stone and pounds.

> Volumes are much more common in cups, gallons, pints than metric. Weights are more common in pounds and ounces than metric.

Your experience seems to be very different to mine. To be honest I have no idea what a gallon even is, and no intuitive concept of an ounce. The only place I have ever seen measurements in "cups" is one chicken biryani recipe I found on an American website. (I agree it's bizarre: half a cup of mint leaves - wtf?!). Any recipe published in the UK in the last couple of decades tends to be in grams and millilitres. Example picked at random: https://www.bbcgoodfood.com/recipes/chocolate-courgette-cake

Seems like this must vary a lot as my experience is very different.

I rarely see/hear/use imperial outside pints and road signs, or for “sizes” like screen or clothing waist sizes, unless I’m talking to people a generation older than me (I’m 40).

Every recipe site I use either has both or is entirely metric, and I only ever use metric. I’d probably look elsewhere if a search turned up a recipe in imperial only.

Even distances are in KM outside of driving (because of the road signs).

Pretty much everyone I know talks about their weight in KG. Heights do seem pretty split between cm and ft/inches but everyone understands both.

Most liquids except beer and cider (including other alcohol like wine and spirits) are in litres and ml.

It’s very obvious to me how metric-first life is for me because visiting America involves constant conversion and thinking whereas everything in other European countries (which are generally entirely metric) comes easily.

Because they are a weird middle ground. UK uses metric paper, metric weights and measures for _most_ things, metric temperature. Where Imperial starts to slip in is distance when driving (but not when running...), volumes of Beer and Milk (mainly cause we want more beer than 500ml) and body weight (where we use Stones, which is weird). There are probably some other things as well, but metric is the dominant system (for people under 60) for sure.

But so is the United States. In all industries where it matters (science, technology, military, medicine) metric is virtually the only measurement system that's used, not to mention that a lot of products are sold in round metric quantities, not imperial.

The difference is that in the UK nearly everything you interact with in your daily life is in metric. You won't find anything in a UK household in imperial measurements other than the bottle of milk in the fridge.

There is a huge difference.

Ask an average American to give you the length of their car, size of their kitchen or weight of a brick in metric and they'll have no clue. The average British person can do this, because education has been metric for 50+ years and the least-technical industry (e.g. construction, DIY) is metric.

(See e.g. https://www.diy.com/, the largest consumer-facing DIY shop in Britain. It's 20kg of 10mm gravel, doors in millimetres, paint in litres. I can't even see a button offering an imperial conversion.)

/u/sgjohnson said metric is used in "in all industries where it matters". Have you maybe considered that "the length of their car, size of their kitchen or weight of a brick" are all examples of where it _doesn't_ matter?

Exactly. That's the huge difference.

The USA only uses metric in some important industries.

Britain uses it for lots of "unimportant" things, like construction/DIY, medicine, health care, cooking, sport/fitness.

That's absurd to say. Of course people care about the sizes of their cars and kitchens. And they need to know the weight of bricks when thinking about weight tolerances in construction.

And you buy a sheet of plywood that's 1220mm × 2440mm which is totally metric and not just 4×8 wearing a fake moustache.

Or you plan to buy the "metric" one that is 1250mm × 2500mm, but your contractor messes up and buys the "American" size after the studs have been built 625mm apart.

Any American can visualize the size of a two‐liter bottle, thanks to our addiction to soda. Three‐liter is also a commonly available size. I’ve never in my life seen anything sold in quantity of one liter here, though.

Except engineering/architecture. Making design software for architects and civil engineers in Europe then (trying to) introduce it to the US market is a b**h!

Height is nearly always feet and inches.

You mean minimemerica and America’s hat?

All kids in the UK learn metric, and possibly some imperial (but only as a side thing). There are still things colloquially said in imperial, such as weight and height, but if you go to a doctor it will be in cm and kg.

We're still a bit of a mishmash, but it's not as bad as it might seem from outside.

UK is also reversing in parts due to BREXIT.

It isn't really.

The government proposed a consultation on doing so, mostly as a distraction.

I'd eat my hat if anything actually changes, the UK was (partially) metricated over 50 years ago, there's zero appetite for reversing it among people of working age and business concerns will dominate any serious consultation around changing legislation.

There’s also 0 appetite for completing the metrication process.

Sure, but that's little to do with brexit and it's only really Miles (Road Signage) and Pints (of beer) that aren't metricated. Even milk is (legally speaking) sold by the litre.

And 2x4s? (I hear you call them 4×2s over there...)

"two-by-four" is used colloquially in the UK for stuff with that approximate cross section, but wood is generally sold with millimetre measurements.

It’s not even approximate. A typical two by four is around 1.5 by 3.5 inches, which is a full third less material than lumber which literally measures 2 by 4.

IIRC this is because "two by four" refers to the size of the rough-sawn stock, but you buy milled 2x4s, so the difference is simply what's removed in milling. You can get these odd formats (stuff like "78x34 mm") in hardware stores here, too, it's just that they're not used for construction, because construction lumber is "hard metric", i.e. nice round numbers like 40x60 mm etc.

While there's an equivalent size, those are (legally speaking) sold by the mm.

For example: https://www.builderdepot.co.uk/timber-sheets/carcassing-timb...

Note the listing is primarily in mm with the imperial measure along side.

So of course the actual size is still equivalent to the old imperial size because of the history, from a legal perspective it's metric.

Right, the size cannot easily change I suppose, for how could you repair older houses/etc? Or use older building plans?

We (Canada) partially transitioned too, but didn't complete the building supplies part of it.

So food is all metric, roads, speed limits, distances, weights, yet wood is imperial, and tools are metric and imperial.

This makes sense, because with the US so close, and the largest trading partner, imperial cannot fully vanish in some repects, until they get rid of it too.

“Two by four” is a category descriptor, not a measurement. Such products do not have dimensions which equal 2 and 4 in either imperial or metric units.

2x4 is a name of lumber that's not 2 by 4 inches at all.

Are a lot of things still sold as “454g / 1lb” or “568ml / 1 pint” (as I recall from a decade ago)? In most metric countries those would just be “500g” and “500ml”.

The Wikipedia article (https://en.wikipedia.org/wiki/Metrication_in_the_United_King...) mentions three legal exceptions: road traffic signs; pints for draught beer and cider, and milk in returnable containers; and troy ounces for transactions in precious metals.

It doesn't mention one product that is very much in the news at the moment: energy. I'm fairly sure they still sell it by the kWh rather than the MJ.

Colloquially, people still talk about calories rather than kJ in food. (And they do that even in Germany, I think, one of the few places where they measure font sizes in mm rather than points, or so I've heard.)

EDIT: Perhaps kWh counts as metric, even though it's not SI?

Everywhere I've lived people also discuss display sizes in inches despite everything else being metric.

display sizes are in inches everywhere (like in the world) indeed - mostly b/c they are produced in such a way...

And air conditioners. Even on mainland Europe they are mostly advertised in BTUs.

kWh is more metric than imperial, although Joules are of course the standard unit of energy.

Watts are a metric unit, as are seconds. Hours are not formally an SI unit, but at least according to Wikipedia [0] are "officially accepted for use with the SI".

[0] https://en.m.wikipedia.org/wiki/Non-SI_units_mentioned_in_th...

A kilowatt hour is 1000 joules per second over 3600 seconds, the amount of power a 1kW heater uses in 1 hour. Its as metric as the hectare

And 1 Joule is one Newton-metre (i.e. it takes 1 J to pull with a force of 1 N over a distance 1 m).

You are right. Is say it is metric, if not standard SI.

I guess kWh counts as metric, as W is SI and h is accepted by SI (as, for example, in km/h). The Imperial unit is maybe the calorie (I'm not sure though).

EDIT: According to Wikipedia [0], the Imperial unit of energy is ft⋅lbf.

[0] https://en.wikipedia.org/wiki/Foot-pound_(energy)

The calorie is also kind of metric: the energy needed to heat 1 gram of water by 1 degree Celsius.

The kcal (kilocalorie) is what most people mean when they refer to calories in food, and that's just the energy needed to heat 1 kg of water by 1 deg C.

Since a person is mostly water this means that, say if you weigh 100 kg, and eat 1000 kcal of food, that food contains (theoretically) enough energy to heat your body mass by 10 deg C. The units do give a kind of intuitive understanding of the energy in food, while also being based on metric quantities.

The non-metric energy measurement in current discussion in Britain is the therm, 100,000 BTU. It seems natural gas is sold in this measure at some of the London exchanges.

It's sold in MWh in the rest of Europe.

>EDIT: Perhaps kWh counts as metric, even though it's not SI?

No need for perhaps, unless it's btu (or some horse power/hour) it's metric.

There is zero appetite for brexit or for the government by working age people either, all the political choices for the last 10 years have matched the result of what the over 65s want, if nobody under 65 votrs there would have been no difference.

On the other hand if nobody over 65 voted every vote would be different.

His point is that elections are cheap.

Business interests align with hard cash. That's going to lean towards metric.

Over 65s don't "vote" much in businesses, they're retired.

Hardly. Britain's converting to metric -- one inch at a time.

Like USA will begin in 2023!? I could hardly believe it when I heard it, it is barely three centuries away!

No, it's not. Any stories about doing so are just dead cats.

Interestingly enough per wikipedia[1], Myanmar and Liberia uses the A4 format while not using the metric system.

[1]: https://fr.wikipedia.org/wiki/A4_(format)#/media/Fichier:Pre...

The irony there being that the US was in fact one of the first early adopters of the metric system, metric being the official weights and measure system within the USofA and the US foot being literally defined in terms of the underlying base metre.

All imperial units have now been redefined in terms of metric.

Not just adopter: The US was one of the original 17 signatories of the Metre Convention in 1875.

According to US law SI has been the preferred system of weights and measures for US trade and commerce". The transition was not mandatory, so nothing happened.

It’s like how they made yyyy-MM-dd the law in Germany for official communications. No one cared, so they changed it to make it optional when used within Germany or when there is no ambiguity a few years later :D

DIN 5008 should be required reading for anyone ;-)

I do care, though, and use ISO 8601 almost exclusively in writing. And I do know a few others. Perhaps things will change eventually.

By "no one", I meant those that were supposed to use it: Government officials ;) I personally use it as well, and so does my workplace, surprisingly.

We have been using it in Sweden as long as I can remember.

Nothing happened because the US decided to elect Reagan and the plan was effectively shelved.

Don’t pretend UK and Canada are metric.

The UK is far closer to metric and will be even more so shortly, for anyone unaware most kids in the UK aren't even taught imperial units at school any more. There really are only vestigial units left; feet / inches for human height (but not for buildings for example), pints for liquids that are drunk (but not for hot water tanks for example), stone for human weight (but not for boxed items), etc. And for places like N. Ireland it's even less so, milk is sold in litres, etc because of the proximity to (Ro) Ireland (which now has its speed limits in km/h for example).

Milk is sold in litres in the UK, it's really only beer that's sold in pints.

The most common sizes for milk to be sold in are 1.136 litres and 2.272 litres (i.e. 2 pints and 4 pints)

Where is that sold? I've never seen anything other than 500ml, 1l, and 2l.

Normal supermarkets.

If you only buy milk in multiples of 500mL, you're buying a luxury brand or from a corner shop -- both situations use the slightly smaller (vs 568mL) size to make the price seem lower.

You can see at Tesco [1] that Yeo Valley, Arla, Cravendale, Finest, Tesco Filtered are all 1 or 2 litres. "Normal" milk is 2 or 4 pints.

(The EU used to have regulations around this sort of thing, but I think they've unfortunately been repealed for most products. It's why bread was only sold in multiples of 400g -- it meant the merchant couldn't discreetly reduce the size of some/all products.)

[1] https://www.tesco.com/groceries/en-GB/shop/fresh-food/milk-b...

Asda only has it in 500ml and 1l containers. I couldn't be arsed walking to Tesco, and the nearest Morrisons or Sainsburys is a 20-minute drive away.

The dairy that delivers here does 500ml, 1l, and 2l, as does the one I bought milk from before I moved, and the one before I moved the time before that.

https://groceries.asda.com/aisle/chilled-food/milk-butter-cr...

The normal milk is all in pints.

This is true, I have friends 10 years younger than me who were never taught imperial units at school. These people are in their early 20s now, give it another decade or so and they'll start to be the people making decisions. We'll finally be able to rid ourselves of the anachronism of imperial measurements.

There are very few imperial holdovers left in the UK, outside of colloquial use.

Distance on road signs, car speed, engine fuel efficiency, beer pints (though I don't mind this since it means our average drink is larger, easier to say than 568ml as well), and that's it as far as I can recall

My UK friends never talk in metric. They weigh 16 stones and are 6 feet 4 inches. The next town over is about 25 miles, etc.

Yeah, I said outside of colloquial use. People still use it colloquially because it's what they know, but they'll also know metric.

Unfortunately UK still regularly mixes both systems. Plus pints and stone.

Almost everywhere on earth mixes metric with some other system.

Some places even mix metric, imperial, and some traditional pre-imperial system.

That's not the case in the European and Southamerican countries I've visited or have acquaintances in. What countries do you have in mind? I'm quite interested.

The only thing I can think of is that screen diagonals are still measured in inches. Ignoring that, a lot of countries are definitely fully metric with regards to the basic length/weight/time measures

You can find occasional uses in many countries. TV screens are advertised in inches here in Denmark, although I noticed the last one I bought was "34 inch, 86.00cm" in the detailed specification -- the inches were just marketing. Old water pipes have some sort of pre-metric size.

Several countries (e.g. France) use the word pound (livre) to mean 500g, which could confuse visitors into thinking something non-metric is being used. I noticed that in south America.

No one really does it any more, but "half-pound" (halvt pund) in Danish means 250g, which was the common way of ordering butter before the supermarkets took over (and why butter used[0] to come in packages of 250g). Similarly, in Sweden, one mile is 10 km.

[0] These days, and selling butter in 200g packages to keep the prices seemingly low.

> [0] These days, and selling butter in 200g packages to keep the prices seemingly low.

And that's why i do my shopping now based on €/kg. There are some very telling differences between even the same manufacturer: last thing i was looking at was gin [the drink] € per litre. Just a visually minor difference in bottle size was a substantial difference in a) cost and perceived value and b) cost and actual value.

Water piping is still specified in inches, at least in Italy.

Also in Italy, when dealing with agricolture, forestry, and related services, non-SI surface units are still commonly used, at leat in the north:

https://it.wikipedia.org/wiki/Pertica_(unit%C3%A0_di_misura)...

https://it.wikipedia.org/wiki/Giornata_piemontese

https://it.wikipedia.org/wiki/Campo_(unit%C3%A0_di_misura)

> Several countries (e.g. France) use the word pound (livre) to mean 500g

Note that nobody I know below the age of 70 uses the "livre" unit in France. It's something you see pretty much only in old recipes

Cereal production is still expressed in “quintal/hectare” with quintal keeping its old meaning of 100 livres but using the metric ones so 100kg.

Most countries still use inches for wheel sizes, for example.

These are basically “sizes” that are imperial by tradition/accident more than people using them as measurement. If I wear size 32 waist jeans is that imperial? Maybe. I’m not measuring I’m just using it as a known size. Might be inches.

Same for wheels, rifle ammunition, …

I use inches for TVs/monitors and although I’m as metric as they get, I have a 55” TV and my car has 20” rims and so on. Everything has cm, kW instead of horsepower etc listed as well for a TV of course.

As far as I know only a few countries - presumably because of regulation - have switched for absolutely everything. Australia is an example of a country where you can get a 100cm TV.

> Same for wheels, rifle ammunition, …

"But being (as?) this is a .44 Magnum, the most powerful handgun in the world, and would blow your head clean off, you've got to ask yourself one question ..."

(Which totally illustrates your point because it's not really 0.44 inches.)

On the other hand:

"Seven-six-two millimeter. Full metal jacket."

I doubt 32" jeans are 32 inches either. It's just "a size formerly related to inches, now denoted 32 or 32" but not really inches". I think imperial remains for a lot of these "sizes" which aren't quite the same as "measuring". I call my TV 55 in, but if you were to ask me to measure it, I'd call it something in centimeters.

Yes. An extreme example: "Shoe size in the United Kingdom, Ireland, India, Pakistan and South Africa is based on the length of the last used to make the shoes, measured in barleycorns (1⁄3 inch) starting from the smallest size deemed practical, which is called size zero." (Wikipedia)

Tire size like 175/60R16 is mixing units. millimeter, percentage, and inch.

Tyre sizes in Europe are an ungodly mix: 295/30R20 for example measures as:

295mm tyre width, sidewall height is 30% of the width and the wheel it fits in is 20 inches (can't recall whether it's 20 inch radius or diameter).

Diameter...

(Is there anywhere that doesn't use this mix of measures for tire sizes [tyre syzes]?)

Many/most items that were designed many years ago in imperial - tyres etc - are still described in imperial units.

But here in Finland (a completely metric country) things like televisions are still marketed/sold as 44" etc where the cm value could very easily be used.

A key distinction tends to be whether a value is mostly used for internal comparison.

E.g TV sizes are mainly compared with each other, and so the unit used doesn't really matter, and if you want to know the external dimensions it'll typically be given in metric in countries which uses it.

Imperial units (specifically, feet) are dominant in aviation to measure flight altitude. Despite a recommendation of ICAO to use SI units since 1979, only China, Mongolia and a few former-USSR countries (not Russia) use metres to define flight levels. [0]

This leads to two interesting consequences for aircraft that perform international flights from/to China: [1]

- they need to be equipped with two altimetry systems;

- they need to perform small climbs or descents when entering or leaving Chinese airspace, as metric flight levels do not usually match Imperial ones (flight levels are defined by round numbers).

[0] https://en.wikipedia.org/wiki/Flight_level#Metric_flight_lev...

[1] https://skybrary.aero/articles/china-reduced-vertical-separa...

The main argument for imperial units in aviation I have seen relate to the fact that one nautical mile is almost exactly one minute of latitude on earth, and one knot is one nautical mile per hour, and therefore an aviator who may experience a total electrical failure and is left with his "six-pack" of unpowered, passive-only instruments could navigate with a wristwatch and paper chart relatively accurately.

I'm not saying I agree with it, but it is at least understandable!

The nautical mile is a sensible unit for anyone trying to navigate with charts (which, in the worst case, could happen to pilots). Feet, on the other hand, are nonsense.

> Imperial units (specifically, feet) are dominant in aviation to measure flight altitude. Despite a recommendation of ICAO to use SI units since 1979, only China, Mongolia and a few former-USSR countries (not Russia) use metres to define flight levels. [0]

Notice that before the end of WW2, continental European aviation was metric too. For this reason, the instrument panel from a Messerschmidt BF-109 is almost readable for a layperson: https://live.staticflickr.com/3746/14275081012_1f74be13b4_4k...

Beyond all edge cases mentioned by others (I add the bicycle frame size to the list) what is the most shocking for me having imperical units in international air traffic! Feets and pounds and gallons (as far as I know) mixed with SI units. One notable accident is the Gimli Glider where miscommunication occurred in fuel quantity calculations and the airplane took off with very little fuel running out mid air (excellent pilots and great story eventually).

Also naval folks are stubborn too. Own miles, knots as speed, craaazy! : )

I'd like to know if any nation actually uses something other than dpi in printing.

Those things come with the prevailing manufacturing country, which was the US for printers and such. So people just keep it.

DPI is one of my pet peeves, together with points. Why not use mm for font size?

Instead of DPI, one could use µm per px, or px per (c)m if you want something easier to work with at very high DPI.

I know what DPI and points are, but just because I know a few values and can say "that one's large", "this one is small", with no idea how much they act iually measure. With other units I could approximate the viewing distance much better.

> DPI is one of my pet peeves, together with points. Why not use mm for font size?

Easy halving, the same reason why A4 has been extolled.

Defining 1mpt = 0.1mm would be just as good.

Normal text would be 40mpt = 4mm = 11.33pt.

But there are already metric point definitions: https://en.wikipedia.org/wiki/Point_(typography)

Ask a German what their car's power is in kW. It's been more than forty years since PS (HP in German) has been relegated to merely tolerated, as long as the kW number is presented as the primary statement, but people still think in horse powers when talking about cars. Perhaps we are an outlier in the metrified countries, but I'm not convinced, I believe that gp is right.

Other examples are screen sizes: I have no intuition at all about how big 5.5" actually are, but I know where in the current phone market 5.5" would fall (awesomely non-huge!), whereas to my mind, the metric equivalent would carry no information at all ("bigger than a stamp, smaller than a TV"). And for sensor sizes you even have the situation where the imperial number is a "size class" with very little relation to actual size, whereas the metric number usually describes actual size. Completely different numbers. All countries use a combination of metric and some other system.

> Ask a German what their car's power is in kW.

> Other examples are screen sizes

that's common, but not as units of measure, but as marketing.

Same as megapixels in photo cameras.

Nobody measure power in HP, we say "that car has 85 HP" only in speech, but when it matters (for example on car papers) power is express in KW and screens are measured in cm that are also written on the package, they are only marketed in inches.

You would be correct if people had an idea of how much power 1 HP is or the surface of 1 MP camera shot, but they don't know, they only know that 16 MP > 12 MP and 300 HP > 100 HP, they (we) ignore what it actually means.

It is also perceived completely differently depending on context.

A 120HP tractor is not the same thing than a 120HP car or a 120HP motorbike.

According to US measures I'm 5'11, which means nothing to me, while it's obvious to them, because they actually use foot and inches all the time and do math using them.

Also 90F means nothing to me.

In Japan, the floor area of rooms are often measured in terms of Tatami mats (-Jo). You will see this on floor plans when looking at apartments, as well as when buying some items like lights or air purifiers that are advertised as being for certain sized rooms.

It's actually a pretty convenient unit, as long as you're familiar with how large tatami mats are.

Note that this unit isn't used for measuring an entire apartment's floor area though, that's done in meters.

See: https://en.wikipedia.org/wiki/Tatami#Size

Tatami mat size is basically a one-person bed - so you are measuring rooms in terms of how many people would be able to sleep on the floor if spaced evenly :)

Not sure what you mean by "plus pints and stone", when they're just normal imperial measures?

They are imperial units. The trouble is that US Customary and imperial units are often very similar but rarely the same. The US pint (and gallon) are different to the imperial one; the US pound mass (lb) and UK ones became the same after the 1950s, but the "hundredweight" or cwt is different between the two – the US 100 weight is 100 lb; and in the UK it is naturally...112 lb. Of course, both systems are in rare usage in both countries (in the US, I understand in some industrial contexts; in the UK on some road signs for weak bridges). It is for this reason that "ton" is different, because, naturally, in both systems there are 20 hundredweight in a ton.

The whole thing is absolutely mad and most efforts to standardise the systems historically lead to the adoption of the SI unit system for "important" things, as well as a few good intentioned bits of legislation, like the International Yard and Pound agreement [1] which standardised those measures between the US and other former imperial users. Don't get me started on the survey foot, or the hell that arose when the units of classical mechanics, electromagnetism or similar scientific systems had to meet imperial or US customary units...

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

And then there's the mile. Originally comes from the Latin for a thousand (mille) paces, and one pace being 5 foot, so a mile used to be 5000 feet. But now it's a beautifully round 5280 feet. How come?

Well, in the middle ages, the furlong was important, because it was the standard size for farmers' fields (based on how long a furrow an ox could plow without resting). But 8 furlongs didn't fit neatly into a mile, so to make things easier for everybody, the mile got expanded to a nice round 5280 feet, or exactly 8 furlongs.

I always wondered how they got their oxes to need resting at exactly the same number of feet ;)

Maybe they were better at standardizing their draft animals than their distance measurements.

At senior school in the early 2000s, I was taught both metric and imperial and how to convert between them. But I have some friends who are 10 years younger than me (I'm 32, they're 22) who were never taught imperial at school. Neither knew what a 'yard' was.. probably because neither of them drive. At least things are changing!

I used letter-sized paper when I was a kid in Honduras, and if memory serves a number of people use US units.

It’s worth remembering that the UK can almost be counted in that group to some extent - road distance and speed as well as human height and weight are normally defined in imperial measurements. Additionally the Conservatives have proposed return to imperial measurements (though just as a pretty transparent appeal to the “back in my day…” crowd)

I was watching a guitar repair video on YouTube this morning and the luthier referred to the action of the guitar as being "five-and-a-half sixty-fourths". This blew my mind.

Easier than saying "five sixty-fourths and one one-hundred-and-twenty-eighth"

But not easier than eleven one-hundred-and-twenty-eighths, and definitely not easier than 2.2mm.

1/64th of an inch is less than half a milimetre. Does the average DIYer have that type of accuracy and precision?

With calipers, sure. Even without precise measurements, we make size adjustments smaller than that when making a tight fit by sanding or whatever.

Even a shitty chinese desktop planer can get you consistent 0.1mm precision if you perform requisite rituals.

I don't know how easy halving is genius when it comes to A4 paper, but somehow considered hopelessly convoluted when giving measurements in base 2.

This standard isn't part of the metric system though

No, but the post mentions that A0 was chosen to have an area of one square metre. (Actually 0.999 square metres - you need a bit of fudge factor if you want sides in integer millimeters and a ratio of root 2)

I'd say it's part of it in the sense that it's based completely on it. It's not a unit or set of units though.

> The metric system is such a beauty, that it's shocking that is not used everywhere.

You can check with Nassim Nicholas Taleb, I think he nails it. The imperial system is much more natural for people to grasp. A pound is roughly a fist sized rock, but there are no natural objects that weight around one kilogram. And one yard is roughly the length of a step, completely unlike a meter. And so forth. /s

Seriously, I propose a compromise. Europeans give up decimal comma and US gives up imperial measurements. Everyone wins.

From a Canadian comedy group, in the 80s, when we were transitioning to metric....

https://www.youtube.com/watch?v=fjFaKD9BuOc

I can hardly wait for first contact, and the planet has to transition to some galactic standard...

"Why would you humans use water in your unit system? Less than 0.01% of the universe is water! 1 elom of dark mater has a mass of 1 marg, your system is obviously not as logical as this!"

> Europeans give up decimal comma

Never!

c'mon it screws up the csv. I'd personally not use comma for decimals, even though I was taught at school

Simple: dot separated values. ;)

Why not use the ASCII group separator? (0x1D)

Unpopular opinion: english units make sense to normal humans. metric units make it easier to do physics. (i'm a physicist)

That’s just familiriaty bias

Counter opinion: no one who grew up in a country with the metric system would know how to understand "I weigh 14 stones". What stones? Small ones? Big ones? Who decides if it's a big one or a small one? Also, how would I know how much a stone weighs?

It's just silly. It has no more bearing on reality than a kg does.

English units like my 2 litre kettle which I use to fill my 300ml cup with tea? Yes they do make sense.

If you grow up in a country that uses metric basically exclusively, it’s not. I literally cannot visualise 10 feet but if you say three metres I instantly have a feel for how long that is (I even Googled the conversion because I couldn’t be bothered working it out). I wouldn’t have any idea what 100 degrees Fahrenheit felt like if I didn’t know it’s about 38 degrees C. And so on…

This is not an unpopular opinion. Millions of anglophones seem to be unable to grasp or accept that metric measures make intuitive sense to people who use them.

I'll grant that words like inches, pounds and miles have more literary gravitas to them than centimetres, kilograms or kilometers, and it would be a shame to lose those former words completely, but arguing they make more "sense" is really pushing it. I literally have no "sense" of what a "stone" weighs, how deep a "fathom" or a "league" is, how much area a "rood" covers, or how much liquid makes up a fluid ounce, and I doubt I ever will. And they're just some of the more common units!

Also imperial units can be divided into quarters and thirds using whole numbers.

Where this property is useful, you can often choose a different starting 'unit'.

For example, fitted kitchen cupboards are designed in multiples of 150mm, which has plenty of nice factors. A dishwasher might be 600mm wide, or a typical cupboard 450mm.

and 5/32s if you need a better precision?

A meter is one big step. Easy to count out 10 meters

> Europeans give up decimal comma and US gives up imperial measurements.

I’m a European, and I hate decimal comma. When consuming data saved by MS Excel or similar, dealing with decimal commas is an ongoing source of annoyance and compatibility bugs, for all my 22 years in the software industry.

Modern software has American roots. Many programming languages like C, C++ and Python are using dot when printing or parsing floats with their standard libraries. It’s even in the name, these numbers are called “floating point” not “floating comma”.

Also in Excel you can set (as per your language used) the comma as decimal separator, but internally it remains dot, an example is the VBA Evaluate function.

Luckily we have 1l milk boxes. I always compare weight to what 1l of milk would weight.

I looked up the density just in case. 1.035 kg/L. Close enough.

> Seriously, I propose a compromise. Europeans give up decimal comma and US gives up imperial measurements. Everyone wins.

> there are no natural objects that weight around one kilogram

Yes there is: a liter of water (see the beauty?)

> Europeans give up decimal comma and US gives up imperial measurements. Everyone wins.

And US gives up strange day-in-the-middle date format as a bonus to make everyone there sane.

> Yes there is: a liter of water (see the beauty?)

There was /s at the end of the sentence, meaning I was sarcastic:)

>And US gives up strange day-in-the-middle date format as a bonus to make everyone there sane.

We should all switch to the ISO (and some (most?) Asian country) format of Year-Month-Day.

>Europeans give up decimal comma

consider it done

> A pound is roughly a fist sized rock

I've seen quite some fists and they all varied in size. This seems like a really bad idea to use as a reference.

And I've seen many rocks with different densities. Also making it a really bad idea to use as a reference.

Of course pre-metric units were defined by something convenient. A cubit is the length of the forearm.

I don't think Taleb goes into the why.

Metric is clearly superior if you have the social concept that units should be standardized and (as a corralary) that products are commoditized. The idea of a standard commodity, however, didn't really exist before the industrial revolution.

So why would units be standardized before that? The only place units mattered was taxes, and then the unit was whatever the king said it was.

> A cubit is the length of the forearm.

> I don't think Taleb goes into the why.

You can measure rope and cloth using cubits by wrapping them around the fist (which holds one end) and the elbow.

I am pretty sure in modern days most people have easier access to 1L of water or 1kg of flour than a fist sized rock.

> more natural for people to grasp

You added sarcasm flag but sometimes it is more natural. I grew up with metric but can visualize "about an inch" better than "about 2.5cm".

It's common for "metric people" to sometimes use inches and feet in casual reference to certain types of measurements. "She is almost 6 feet tall" is another example that will be used instead of "180 cm" or "1.8 metres".

No one where I live and use metric system even have clue what is the feet and inches mess... Like five foot what? Why not do it properly and say five point something feet like sane systems.

At least here in Western (continental) Europe, it really isn't. I have never heard somebody say something like "She is almost 6 feet tall".

Okay so how would they describe someone's height?

For example, telling a story about their daughter who has grown quickly and is now "almost [n units] tall"? Are you saying they would use centimeters and expect their listener to know what "184 cm" looks like?

I'm not saying metric people use "5 foot 9", but it's common in my country (Australia) at least to use "6 foot" because that's a nice easy rounded benchmark. In metric height, there is no benchmark until 2 metres tall, which is a rare height even for men.

People would either use 10s of centimetres, so saying "my daughter is almost 170cm tall" or use a measure relative to somebody else, often including "heads" or "half-heads" ("my daughter is already half a head taller than me"). You might want to argue that a "head" is pretty similar to a foot though.

As a Brit, I completely support the US giving up imperial measures for Europeans giving up decimal commas.

The US doesn't use Imperial units, it wasn't part of the British Empire at the time that system was standardised.

It uses US Statute Units which are similar but not always the same as Imperial Units.

There are some very important differences...

Hence the reason that no Brit is ever impressed with a "pint" served in a US bar. It looks like the barman forgot to pour all of it. :P

We should retire Imperial, US and Nautical units and switch everything to SI Metric.

Having several definitions of mile, pint, gallon, foot, etc in use, at the same time, is just feckin' silly.

Ignoring the /s ... a yard is still a fair bit longer than the average stride length - it's probably about right if you're close to 2m tall though. OTOH an average male adult's hip is around 1m from the ground. Pineapples and cabbages typically weigh close to 1kg. Fist-sized rocks can vary enormously in weight - anywhere from a few 100g (pumice etc) to over 1kg (pyrite, assuming a large hand size).

Everything that matters to people is as easily mapped out to metric units. I know how to span my fingers to get either 10 cm, 20 cm or 25 cm, and how to pace my steps to get 1 m. Arm span is easy too, I simply get my height and can work based on that, as I do when measuring heights. Step pacing is quite visible and I see it regularly in the open in various contexts. Metric people know how to do these kinds of things. Real estate agents or construction workers might refine their paces to achieve greater precision, but even people who have never had the curiosity or need to do so can get a rough estimate of a meter that's probably good enough and not much more imprecise than the length of the step of another person (like feet… Charlemagne's giant foot became the standard unit for peasants with half the foot size for centuries…). I've never felt any personal interest in measuring weights based on fist-sized rocks either (sandstone or granite by the way? you've got all sorts of density ranges out there…), but I'm sure you could find something as intuitive if you needed it and I sure can get of sense of weights expressed in grams in a kitchen and have also developed a pretty good intuitive feel of heavier stuff based on a few experiences moving 25 kg and 50 kg bags around that proves useful from time to time.

Is it shocking that the number of hours in a day or months in a year is not divisible by 10?

Doesn't it make sense for some things to divide by 3 and 4, like a year, so that a season is 3 months long, instead of 2.5 months long (as in the old 10-month year system, ending in December)?

Does it not make sense to use a human scale for certain things, like outdoor weather (as opposed to say, temperatures inside of machinery):

In Fahrenheit: 0: very cold to people; 100: very hot to people.

In Celsius: 0: not that cold; 100: I died 50 degrees ago.

The metric system seems to me to be forced onto things where it does not fit, when in fact it's fine to use more than one system when contextually appropriate.

After all, none of us think it weird to use bases 2, 10, or 16 for different things on our computers.

> Doesn't it make sense for some things to divide by 3 and 4, like a year, so that a season is 3 months long, instead of 2.5 months long (as in the old 10-month year system, ending in December)?

The metric system also uses twelve months per year, so what is your point?

> Does it not make sense to use a human scale for certain things, like outdoor weather (as opposed to say, temperatures inside of machinery):

Yes, Fahrenheit works 'better' than Celsuis for describing weather temperatures. But it does arguably worse at pretty much everything else, including other everyday occurrences like cooking or washing clothes.

As an aside, 12 would arguably be the better base for an everyday number system, but we are where we are (and contrary to what's commonly claimed, the imperial system isn't derived from base 12 either - 12 is used in a few places, but most proportions are historically grown and fairly random).

In Celcius, 0 water freezes, 100 water boils. Very convenient for weather and cooking. For the rest, what is hot weather or cold weather is very subjective, so I don't really see any use to define a scale on the base of that.

Do people actually directly measure boiling water? I've never seen that. It's a self-apparent phenomenon. I've never heard of anyone measuring anything while cooking where it matters which temperature scale they're using.

It is really useful for calibration. Stick a thermometer in there and you can tell how accurate it is.

Calibration of what? The thermometer? When do you need to calibrate a thermometer at the temperature of boiling water and how does the temperature scale affect that in any way?

The fact that calibration points at sea level of celsius are very easy to produce. Just need some ice and then some boiling water. And I can't even get my hands on pure ammonium chloride. Just some mixed stuff.

Yes, calibration of the thermometer. For example with sous vide cooking, it can be useful to know how accurate your equipment is since recipes are often expressed in precise temperatures.

Thanks for the example, but I'm still not sure what that has to do with the scale since you only care about a single number in that case.

I need to look up sous vide cooking. I've never heard of it before. Seems pretty interesting.

You need at least two points to determine the slope of the thermometer, 0 and 100 as freezing and boiling point of water makes that reproducible.

well the boiling point depends on the elevation (pressure), so that tells you nothing at all.

Unless you live at altitude 0, I wouldn’t do that if I were you.

Celsius and Fahrenheit don’t make much difference. That’s the only part of the imperial system which is not incredibly inferior to metric.

The metric system is based mostly on water. 1 kg = 1 litre = 1000 cm3

For people serious about their tea, measuring 70, 80 or 90 Celsius is vital.

Oh but that was part of the original plan!!

https://en.m.wikipedia.org/wiki/French_Republican_calendar

10 months per year, 10 days per week.

I've seen the temperature argument and it never has made sense to me. What does "very cold" and "very hot" mean? For me living in Spain, 40º is "very hot", but I've seen people living in northern countries complaining about 30º. Viceversa with "cold".

The only reason Fahrenheit looks like "a human scale" is because you're used to it. At least Celsius has clear reference points (everybody knows how cold is "freezing water" and how hot is "boiling water").

> Doesn't it make sense for some things to divide by 3 and 4, like a year, so that a season is 3 months long, instead of 2.5 months long (as in the old 10-month year system, ending in December)?

Programmers all around the world would first hate you for changing things, and then love you for making a consistent dating system.

But, seriously now, dates are a bit of a difficult system to change. You want to be able to refer to past dates without too much confusion, and also there are outside restrictions such as the length of a year compared to a day (not many integer divisors of 365 days).

I moved from a Fahrenheit country to a Celsius country, and let me tell you that knowing 0° was freezing and 100° was boiling did not help me decided whether I should put on a jacket when it's 17° outside.

(I now know how to interpret Celsius, but it involved memorising certain fixed points. The "30 is hot, 20 is nice, 10 is cold, 0 is ice" rhyme is a good one.)

As opposed to what? I put on a jacket at 19°C. That's 66.2 Fahrenheit. How does it help?

My point is that everyone saying "Celsius is so easy, look at how logical it is!" are missing the point that you still have to memorize a bunch of temperatures. Nobody in their right mind is going to say "Well, it's 20% of the way between water freezing and boiling, so I'll wear long sleeves but no jacket today".

Both celsius and fahrenheit are completely arbitrary, just use whichever one everyone around you is using and you'll be alright. You'll internalise the scale eventually.

It's the one part of the metric system that isn't innately superior to imperial/customary

> I now know how to interpret Celsius, but it involved memorising certain fixed points

But that's literally the argument given for Fahrenheit.

No really. The "comfortability" points are basically separated by 10 degrees F, with only 32 degrees F being the special one.

My point is that everyone saying "Celsius is so easy, look at how logical it is!" are missing the point that you still have to memorize a bunch of temperatures. Nobody in their right mind is going to say "Well, it's 20% of the way between water freezing and boiling, so I'll wear long sleeves but no jacket today".

So you agree that the argument for it "feeling more natural" is actually, "I've already memorised a number"?

Celsius does the same thing but with 5 cadence; what you explain is a habit - 70 Frankenstein being 21 science is just as helpful.

For me how it works - 0 is freezing point, 36 is body temperature (you learn that around 4-5y of age), and it's imprinted heavily. Half your body temp is about to begin feeling cold (in general). Picked body temp as it is 100F (originally 100F was meant to be the body temperature)

Fahrenheit (the man) was himself a physicist... he invented the mercury thermometer. That's pretty scientific.

So calling it "Frankenstein and Science" is a little silly, especially when we have an absolute scientific scale (Kelvin).

Actually, nobody complains that we use both Celsius and Kelvin, so what problem is there with a third scale for people, if the former two are for industry and science respectively?

>So calling it "Frankenstein and Science" is a little silly, especially when we have an absolute scientific scale (Kelvin).

That was unnecessary, an obvious joke about both, and how people feel about them, etc. C and K scale the same way, so C is just an offset K (or vise versa). Both C and F are arbitrary, of course - zero (as developer) being the phase change of the water does make more sense to me; again arbitrary.

And if I moved to a Fahrenheit country I wouldn't know what to wear when it's 60 degrees. That's the point, that both scales need some "getting used to". Fahrenheit is no more natural than Celsius in that regard, and also has the issue of not having reference points.

0F is the brine freezing point. The 100 is better - originally thought as human body temperature, now it's a mild fever.

Then again 17 is pretty close to temperature you are entirely unsure if you use jacket or not. On other hand it is pretty pleasant summer temperature. On other if it is windy it might not be so nice.

very hot - about 35.5C or so, when you cannot dissipate heat with sweating. 30C is just uncomfortable but totally fine.

Also an year is not even 365days.

> very hot - about 35.5C or so, when you cannot dissipate heat with sweating. 30C is just uncomfortable but totally fine.

That's not only subjective but also depends on humidity. 34º with high humidity can feel far hotter than 38º in dry weather.

Celcius 0 in weather is pretty handy. If it is at that or below I know that I should be aware that it might be slippery so drive more carefully and check where I put my foot. Much below that those things aren't that big issue but better wear more. And above that somewhat I can survive outside okay.

I will admit celsius 0 is useful for farming (will there be a bud-killing frost?), but I have no issue with the use of celsius in industry; there are merits for each system, and we don't need to eliminate one to get the benefit of the other. We can use each in their context, like we do with many other things.

0C is mostly useful on the road, knowing when it becomes slippery - around 3-4C as ice can form above 0 as well

> In Fahrenheit: 0: very cold to people; 100: very hot to people. > > In Celsius: 0: not that cold; 100: I died 50 degrees ago.

Celsius 0 and below, warning there could be ice on the road.

Hot/cold is too subjective. My relation to heat/cold was not the same when I was living in north of France, Swiss alps and now in south of Spain.

September to December contain the numbers 7 to 10 not because the roman year was 10 months long, but because they started counting in March instead of January. That's also why February is a bit shorter: They ran out of days in the last month of the year.

> The fact that a liter of water has a relation with the size of the paper we use is just poetry.

It’s not that there is a relation, it’s that it’s simple. If you put 288/187 inch of water on a standard letter paper, you get exactly one cubic foot of water, but I wouldn’t say “The fact that a cubic foot of water has a relation with the size of the paper we use is just poetry”.

It also is a happy coincidence that the idea “if we cut a page in half, the two parts should have the same proportions” leads to usable paper sizes. If it weren’t, we wouldn’t have this system.

And has this ever been tried for 3D, say in storage boxes? The proportions of a box would be about 1 : 5/4 : 25/16. That’s a bit cube-ish, but doesn’t look unusable to me.

There's these storage boxes whose size is defined by the dimensions of an EUR-pallet [1]: https://euronormbehaelter.com/faq/arten-euronormbehaelter/. Each smaller container divides some dimension by 2. However, I don't think they follow the golden ratio at all.

[1]: https://en.wikipedia.org/wiki/EUR-pallet

Beauty doesn't necessarily mean practical in all cases. In all honesty, people who grew up with the metric system don't usually understand how practical Fahrenheit and other non-metric units often are (not always are). Are they hard to calculate with? Yes, sometimes. But they usually directly map to average human experience. For example, humans experience temperatures in the range of 0 - 100 degrees F most of the time. That's -17.8 - 37.78 degrees C. The Celsius range doesn't really make sense in the context of daily experience and is less fine-grained at that. Yes, 0-100 degrees C is freezing to boiling, but humans don't live in that range.

The metric system is great for symmetry and calculations but that doesn't always map to practical quantities in those units, in my personal opinion. It's kind of funny when foreign friends will explain to me metric units, when I already know them, but they don't understand anything about non-metric units or their practicality.

Edit: I should have known to make this comment, because it's going to get bikeshedded to death (already is). The summary of my point was to say that the metric system is perfect for calculations and representations, but the non-metric systems can often serve more practical purposes. Not always but often. In other words, for daily, non-engineering uses, there's really not much of a strong winner aside from people's country of origin. Even for paper, it's a toss-up for me. I find for notebooks, the A<x> sizes are nice and preferred by me, but US letter size is sometimes more preferred over A4 paper. A4 paper is nice for mathematical notes but can often get in the way of diagramming due to the narrowness.

There just seems to be a superiority complex of those that use the metric system, but I don't really get it. Note the use of the word "shocking" in the comment I replied to.

Edit 2: Commenting on scales really seems to grind some gears and gets people going. I'm okay with stating that the scales used for various measurements are fairly arbitrary in daily life and that there's pros and cons to both, but still disagree that it's shocking various places don't use the metric system. They certainly cause issues in engineering systems though.

Your subjective experience of temperature has three digits of precision? Because mine sure doesn't.

My daily experience absolutely fits into the 0-50 range.

0C outside means the ground is hard to work with. 32F is such an arbitrary number when dealing is concrete reality outside.

Well mine and most everyone's is almost exactly 0-100 degrees F, and 50 degrees C is on the extreme.

Yes, 32 degrees F is arbitrary, but so are several of the milestones in Celsius.

I think my argument is that Fahrenheit is more natural most of the time, but both scales have their sweet spots (which makes sense given their relative nature). But I can't see any clear argument that says Celsius is superior all the time.

> Well mine and most everyone's is almost exactly 0-100 degrees F, and 50 degrees C is on the extreme.

You don't cook?

Their point was related to outside temperatures, which is what most people use temperatures for. And although I've never used Fahrenheit for anything, I don't think the 100c = boiling water is useful in day-to-day life.

I've used temperatures in the 60 something to 80 something range to measure the inside of food, my oven goes anywhere from 160 to 220 degrees, but water boils when it goes all bubbly. I know that that's at 100 degrees, but I don't do anything with that info.

I don't agree with bmitc's point that Fahrenheit feels more natural. But it seems like that anytime someone has something positive to say about Fahrenheit or imperial measurement, 10 different people need to tell them how wrong they are, and how there can't be anything positive about those systems of measurement. That doesn't seem necessary to me. Especially with temperatures where everyone just remembers a couple of numbers and associates them to a certain feeling or application, and whatever you've used your entire life will feel better or more natural.

Likewise anytime anybody says that Celsius feels natural as well, you also have 10 people tell them that they are wrong and Fahrenheit is a much better fit for human beings.

Now I think these discussions often go about cherry picking examples and just limit the discussion to outside temperatures is such a cherry picking.

The real power of the metric system comes from going all-in. You can't use everything but the temperature scale. If you would do that it would be even more obvious how disconnected the temperature scale is to the whole system.

Yeah, having metric everything makes it easy to do conversions and correlating with different properties of matter, you're using the language of science (and most of the world), with proper definitions in terms of reality: atoms (for kg), distance in terms of c*some_time, volume related to mass (1ml of water => 1g of water, you can get very precise with temperature as an input). Having a standard for orders of magnitude that's consistent (micro, milli, kilo, mega, giga) is just the cherry on top.

I use the knowledge of the temperature of boiling water to calculate "how much boiling water I need to add to a water in room temperature to have my prefect tea brewing temperature".

Considering that 100F is almost 40C just put your scale from 0-40. It's completely subjective.

0C wear a woolly hat

10C wear a jacket or sweater

20C Teeshirt and jeans weather

30C Teeshirt and shorts weather

40C Get in the shade and keep hydrated

50C You want to avoid this end of the scale

It's almost all defending against the pro-Fahrenheit folks making strange arguments promoting it, like somehow you can't measure your life unless it's in F.

> It's almost all defending against the pro-Fahrenheit folks making strange arguments promoting it, like somehow you can't measure your life unless it's in F.

I didn't make that argument. Fahrenheit is more natural in a lot of cases because of the range and delineation between whole number temperatures. Celsius is slightly less so but not all the time.

My entire point, which was lost in the bikeshedding is that it is not "shocking" that the metric system isn't used everywhere in daily experience because non-metric systems were literally invented to be useful and practical. Are they perfect? No. Neither is the metric system for daily human use.

The U.S. is a big place and thus has wide-ranging temperatures, and that probably contributes to resistance to getting rid of Fahrenheit, amongst other things and other measurement systems. The U.S. built a huge amount of modern infrastructure before anyone else and has never experienced a "rebuild" period. For non-engineering purposes, there's no downside to using non-metric units, and a lot of downsides in converting. As the back and forth here shows, there's probably a strong argument to be made that the measuring systems don't matter at all in an ideal world where it's free to convert entire countries back and forth between them. But for some reason, a lot of the world feels very superior for using the metric system.

Again. Not "shocking" as the original comment I replied to mentioned.

Fahrenheit was defined the way it was not because it was "invented to be useful and practical", but because a mixture of brine to set 0℉ was easy to concoct reliably. That's as close as it got to being "practical".

Every other argument seems to boil down to "I'm not familiar with it, so it's hard", "dealing with 10s is easier than 5s", and "Fahrenheit has more resolution because I've forgotten decimal numbers exist".

The actual superpower of metric is that all the units relate to each other in simple ways. For instance most liquids you and I deal with on a daily basis have a similar density to water, so if you've got 100g of it, it's going to be ~100ml. You don't need to deal with arbitrary artifacts of the measuring system beyond the unit prefixes.

"The US is a big place" , but the world outside the US using Celsius is even bigger, more populated, and with more temperature differences.

Fahrenheit being more natural is purely subjective, there's no good reason at all for it.

Keeping the imperial system is just a matter of convinience because Americans are used to it and changing everything is difficult. Also some people think producers of food and any objects to sell might lose some margin by converting and rounding to the next round number of the new unit

> Fahrenheit is more natural in a lot of cases because of the range and delineation between whole number temperatures. Celsius is slightly less so but not all the time.

You mean "I'm already used to something and I dislike other things."

It comes down to familiarity, but -20 to 40 degrees Celsius isn't that weird a scale, either. You're going to remember more or less arbitrary values for certain things anyway (too hot to be comfortably outside, cold enough to need a jacket, cold enough to need gloves, cold enough to need multiple layers, etc.). In that sense, yeah, Kelvin would be impractical, as would be a theoretical temperature scale that compressed most human-relevant temperatures between 0 and 2 or so. But that's not the case and degrees Celsius is perfectly viable for everyday use, as is (I imagine and you say) degrees Fahrenheit.

Temperature near 0°C is very important when we travel (meteo, ...). Temperature near 100°C is important when we cook (eggs, pasta, rice).

We can leave hands in water at 50°C. Above, it slightly start to cause burns.

This is a range that make a lot of sense IMHO.

0 degrees C is certainly nice for freezing, but Celsius loses its usefulness, in my opinion, at the upper ranges. Fahrenheit is okay though, because 32 isn't that hard of a number and 0 degrees F is a big milestone because it's a big (i.e., dangerous) milestone in outside temperatures.

> Temperature near 100°C is important when we cook (eggs, pasta, rice).

When does that matter on the scale being used? Someone else mentioned this, but I've never known anyone to be taking direct measurements of these things when cooking aside from baking. It's pretty clear when water is boiling.

> We can leave hands in water at 50°C. Above, it slightly start to cause burns.

When has that been useful and dependent upon a temperature measurement (and thus a temperature scale)?

You are putting far too much weight in arbitrary numbers, probably due to personal familiarity.

0°F is a big milestone? I'll claim 1°F should be the milestone instead, or -5.4°F, or 2.33333°F.

15°C or 12°C or something is an important temperature if you live in the tropics without a heating system.

> You are putting far too much weight in arbitrary numbers, probably due to personal familiarity

bmitc reacted to the comment that said "Temperature near 100°C is important when we cook (eggs, pasta, rice)." By asking when that info is important. They are not the one here that put weight in arbitrary numbers, at least in that last comment.

For the tea preparation, we shall use hot water below 100°C. french site: https://www.fauchon.com/fr/mag/conseils/quelle-temperature-d...

Or just; don't use boiling water.

I don't feel like either Celsius or Fahrenheit are any more natural than the other in most contexts. It just comes down to what you're used to. They're both relatively arbitrary.

I'm not sure why 0f is a big dangerous milestone in outdoor temperature. Is -18c/-1f really that different to -17c/1f? If anything, there's a much stronger argument that 0c is the dangerous milestone because that's when you get ice.

Really the only temperatures I care about on a day to day basis are like, freezing temperature (0c/32f), room temperature (20c/70f-ish) and various benchmark outdoor temperatures, like 30c/90f being hot and 40c/100f being potentially dangerous. You can +- a few C either way on any of those (except freezing) and it doesn't really make a difference. Cooking, even baking, is usually fine within around 10c. Sous vide is apparently a lot more sensitive but I've never done that.

Very occasionally I deal with something something like a kettle thermostat or boiler thermostat, where I might choose something like 100c/212f or 50c/120f respectively. I also use an IR thermometer for cooking pancakes, pizza and monitoring my wood stove - but neither Farenheit or Celcius are any more useful in that context.

I agree with all that for the most part. Having used Celsius at various times, I still feel Fahrenheit is better for outdoor temperatures because of the range, but yea, there's undeniably a bias there no matter how much I think I reason about it.

I think the idea that it is indeed relatively arbitrary probably summarizes a more accurate reaction to the comment I originally replied to.

Nope. Have you ever used a thermometer to measure the temperature of water for boiling pasta and rice? Ask yourself why.

Freezing point being 0°C is handy because it is important to know when outdoor temperature crosses this point for multiple reasons - water is too common and important substance to ignore its properties. In Fahrenheit freezing point is a hard to remember value (for someone who used to Celsius).

I see nothing special about -17.8°C +37.78°C range except that 37.78°C is very hot. But why 37.78 and not some other value? It is arbitrary. And -17.8°C is even more arbitrary - it is not the coldest weather in many northern regions.

> But they usually directly map to average human experience. > they don't understand anything about non-metric units or their practicality.

They don't see it the same way that you don't see that the units are totally irrelevant, the brain just have to form habits around the relation between the numbers and the world, but as soon as there are consistant and predictable, the extra effort or lack of doesn't change much about their practicality. The habits are formed early, and doesn't require any extra work once set.

Having physical relationships between units without having to remembering ratios can be handy time to times, and for your entire life.

Can you give an example of a non-metric unit that is more practical than it's metric counterpart outside of familiarity?

Celsius is better for cooking, the Fahrenheit scale is better for hot weather, for colder weather, I prefer Celsius, around 0°C means water is freezing, so, snow, ice, etc...

Feet or inches are, I think, a bit more human friendly than meters, but only when used by themselves, that factor of 12 is just weird in a base 10 system. I know that the argument is that you can divide by 3 and 4 easily, but when it matters, metric countries simply make standard sizes a multiple of 12 (ex:120mm).

For volumes and weights, I find absolutely no redeeming feature to the imperial / US customary system. The kilogram is a perfectly fine unit, so is the liter, and that both are the same when we are weighing water is a very useful property. Because many things are around the density of water, you know that most things that fits in a 1L bottle weight around a kg, and you can often measure volumes with a scale without conversion.

Metric is not the most practical for every single situation, but it is more practical when used as a whole, that is, when you need to deal with with several quantities at the same time (ex: masses and lengths). And there are everyday situation where it is simply better in my opinion, like cooking.

About as reasonable a take as you can get.

Can you elaborate on the cooking though? I've seen that mentioned here a couple of times, and I'm not sure I follow. I'm from a Fahrenheit country and my wife from a Celsius country, and it's never caused any issues or confusion in the kitchen. But maybe you mean also for the volumetric measurements as well (or primarily)?

It is not about confusion, it is about convenience. I like the idea that water boils at 100°C since it is maybe the most important temperature in cooking. I like the fact that I can measure 500mL of water on a scale as 500g (and other liquids with a small error). Small details that make it more convenient in metric.

But there is something else, and I am asking you the question. Since you and your wife live in countries with different unit systems, isn't problem when doing each others recipes?

I mean I live in Europe, and if the recipe calls for 4 ounces of butter, I don't have a 4 ounces stick of butter, I have a 125g stick, which is not exactly that. A quart of milk is not exactly the liter I have. And my oven doesn't do 350°F, it does 180°C which is not exactly the same. In the end, I will have to adjust the recipe to my standards, and things may be lost (or gained) in translation, but it won't be the same.

For what it's worth, if looking for an English recipe I just add "UK" to my search to avoid American measurements. I find British recipes are also less likely to require some processed American ingredient unavailable in the EU. ("Add the miracle whip," what?)

> Celsius is better for cooking

Not really. Celsius maps to the boiling and freezing points of water in Paris. Live in Denver and you're screwed. And -- this is important -- nobody measures the freezing points and boiling points of water, because during its phase changes water holds to that temperature automatically.

Fahrenheit is also twice the resolution of Celsius. This is highly advantageoous for body temperature, medicine, cooking, and other functions. Celsius's integer resolution is horrible.

You give temperatures for cooking with 5 C resolution anyway, why would you need more than 0.5 C resolution?

Okay, highly advantageous for body temperature and medicine, only marginally advantageous for cooking.

Unnecessary precision is a disadvantage. That's why speed limits are 60 mph not 316800 feet per hour.

This sounds like trolling. Fahrenheit nearly perfectly nailed the intervals of importance in body temperature when it comes to child fevers, say. As no doubt you know well, 100 is "mild", 101 is "significant", 102 is "requires medicine to bring fever down" and 103 is "call the doctor". That's a huge difference in a range of 3 units. Now ask yourself what those values are in celsius.

I meant cooking. You wrote that Fahrenheit has "marginal advantage" in cooking, I responded that unnecessary precision is a disadvantage if anything.

As for body temperature the rule of thumb as I know it is sth like this:

    36 - fine
    36.6 - the theoretical perfect temperature (but it's a lie [1])
    37 - observe
    38 - go see doctor (but no rush)
    39 and higher - go see doctor immediately

These also depend on where you measure the temperature, mostly people measure in armpits here, if you do oral or rectal then they will differ. Remote measuring on your forehead is almost useless.

As for "requires medicine" - I don't remember having to make that decision, if I had 38+ C fever I just went to a doctor anyway.

[1] the actual perfect temperature changes by almost 0.5 C between people, time of day, time of month (for women) and other factors (measurement error). If you used thermal method of anticonception you'll know how variable it really is.

> Celsius is better for cooking

As far as I'm aware, there's no winner for cooking. I've never seen a recipe that required temperature more than as a value that could be provided in any units as long as you have equipment in those units (i.e. I'm not doing math with them). Putting "400°F" or "200°C" or "475 K" or some arbitrary "oven level 5" into my oven shouldn't really change how it comes out.

On the stovetop, I've never had an instruction with a temperature attached besides "interior temperature must reach X" or keeping something at a near-boiling temperature, which I've never needed a thermometer for, and 90% of the time I'm improvising without caring what the temperature is outside of "hot enough to cook the way I want but not too hot".

Sous-vide? It needs the temperature within a tight range, but the scale attached to the numbers doesn't matter as long as it's the one my thermometer uses. Double boiler? Doesn't even need you to use a thermometer to keep the temperature right. Give me a kitchen with everything in unpronouncible alien temperature units and I'd do just fine.

U.S. Letter size could behave like A4 (root 2) if it were 8.5" x 12" ... not a huge stretch.

(Or 7.75" x 11", approximately, if you prefer.)

But then it wouldn't be US Letter.

There are other paper sizes based around the A series that fit relate back to it as part of a geometric progression, which means stuff fits neatly together. For instance, the C and DL series, which are used for envelopes, with a C4 envelope being exactly the right size for a sheet of A4 paper.

To be sure, but the point I was questioning was that A4 is too skinny for most use cases, that U.S. Letter was preferred in that regard. Adding 9% to the length of U.S. Letter doesn't seem to make it suddenly overly skinny.

Bad for origami though. Ditto with regard to A4. :-)

Preferred by whom? I've never encountered a use case where A4 was too skinny. And it certainly never stopped anyone from making paper airplanes from whole sheets at school. A4 folds neatly to sheets of the same ratio, which is its party trick and why the DL and C series of envelopes are a thing.

Not this crap again.

Fahrenheit maps to your human experience because it's what you grew up with.

To me, Celsius maps to my human experience, because it's what I grew up with.

That's it. That's all it is, and that's the only reason you think it maps better.

No. Fahrenheit really is better than Celsius regardless of your reluctance to admit it.

1. 0 Fahrenheit is close to the typical minimum temperature, and 100 close to the typical maximum temperature, which can be tolerated by humans. Celsius 0 and 100 aren't even remotely close to this: it's surprisingly awful.

2. Fahrenheit has nearly twice the integer resolution of Celsius. This is particularly helpful in describing body temperature.

3. Celsius seems like it'd be useful in cooking but it is not really. Sure, 0 and 100 describe the boiling point and freezing points of water -- in Paris only -- but these are phase changes in water. Nobody says "now hold the temperature at 100C", because water naturally fixes to 100C the entire time it is undergoing its phase change. You don't need to measure it. And Fahrenheit's higher resolution is again very helpful.

4. Scientists don't use Celsius or Fahrenheit. They use Kelvin. Both Celsius and Fahrenheit convert to Kelvin with a linear transformation.

I have no problem believing that Americans find the Fahrenheit system intuitive, but you are failing to see that for metric users, Celsius is 100% intuitive. I know exactly what sort of clothes to wear for each gradation (assuming it's not something insane like -60C in which case I'm staying home anyway), whereas I genuinely cannot do the same calculus with just Fahrenheit, even taking into account the 0-100 concept of Fahrenheit, which is in itself busted in various regions from Canada to Saudi Arabia. I have to constantly remind myself of what Fahrenheit means, because I never grew up with it.

This is a theory of mind issue.

> for metric users, Celsius is 100% intuitive.

For metric users, Celsius is 100% familiar. Intuitive means that there are a bunch of hints that can give you an idea of values that you don't know. The fact that 0° Fahrenheit is about as cold as you can easily stand and 100° Fahrenheit is about as hot as you can easily stand is something that gives you an intuition: if it's as hot as I can stand, it's about 100°, if it's as cold as I can possibly stand, it's about 0°. I can figure out intermediate values through converting my feelings into a percentage.

You can of course do that with Celsius too, but Celsius hasn't been built around a range of human feeling, it's been built around the phase changes of water. You just have to remember the human comfort range in Celsius, do all the same calculations as above, multiply the result by the difference between your low human range and your high human range, then add that to your low human range to get an answer. There's no help, and it might as well be arbitrary.

This is a post-facto rationalization for two reasons.

The first is that the Fahrenheit scale wasn't built around a range of human feeling, but originally around a substance whose temperature is easy to stabilize. Following this, the human temperature was set at 96 (later adapted to 98.6) and the melting point of ice at 32 to have 64 gradations to help with measurements linked to specific hardware. If it was designed around human feeling, then 98.6 and the freezing temperature of brine is hardly helpful.

The second is that if it were intuitive on its own, people who don't use the system regularly would still be able to remember the logic, but that's not what typically happens. Every time I need to think in Fahrenheit (which tends to only be online debates about this very topic), I can't picture anything clearly even with the purported 0 to 100 concept. It is a subjective appraisal of temperature that can't help me convert feelings into anything useful because the limits are still arbitrary. If -17.7C is the lowest a person can possibly stand, then Canadians are gonna be iced out. If 37.7C is the highest a person can possibly stand, Saudis are cooked. The number of regions that hold a range that's appreciably close to that 0 to 100 is quite small.

> The first is that the Fahrenheit scale wasn't built around a range of human feeling

How and why Fahrenheit was developed is completely immaterial: what is material is whether and how its range is of value to its users now.

> Every time I need to think in Fahrenheit (which tends to only be online debates about this very topic), I can't picture anything clearly even with the purported 0 to 100 concept.

Your argument is "because I'm not used to Fahrenheit, it must not offer an advantage to people used to it"? Really? C'mon.

> Your argument is "because I'm not used to Fahrenheit, it must not offer an advantage to people used to it"? Really?

But that's your argument for Fahrenheit...

> 4. Scientists don't use Celsius or Fahrenheit. They use Kelvin. Both Celsius and Fahrenheit convert to Kelvin with a linear transformation.

But the slope of the Celsius<->Kelvin is 1.

Celcius is more useful in weather forecasting, because for a lot of people it's important to know whether the water outdoors will be frozen or liquid. Example - it's useful to know if there will be ice on road and it's useful to know if the plants outside will die due to ground freeze at night. Giving the temperature in C answers both questions automatically.

"Typical" maximum and minimum temperature as limits are meaningless, different places have significantly different minimum and maximum temperatures.

The resolution might be better for body temperature (I have my doubts, we measure to decimal point in C), but certainly not for cooking. Nobody needs to know the difference between 200 and 201 F in cooking.

> Both Celsius and Fahrenheit convert to Kelvin with a linear transformation.

C doesn't need multiplication tho.

What on earth is "the typical minimum temperature that can be tolerated by humans" though? There are people who seem fine living in parts of the world where it's regularly -30C (somewhat less than 0F), and many of us that would find anything much less than 0C (32F!) regularly to be pretty much intolerable. Resolution is an issue for measuring fever, so we use a single decimal point (36.8 is normal, 37.1 is elevated etc.). Other than that it just never comes up. Agreed that 100C being the boiling point of water isn't that useful for setting oven temperature etc., but at least you know something that's 100C is going to be as hot to touch as putting your hand under scolding water (and likewise 0C is going to be as cold as ice. You're willing to sacrifice that?). Kelvin is far easier to mentally convert to Celsius than Fahrenheit, and at any rate Celsius is still used extensively by biologists, behavioral scientists etc.

> many of us that would find anything much less than 0C (32F!) regularly to be pretty much intolerable.

Really? Barely long sleeve weather.

For you.

Here we see the difference between subjective and objective plainly expressed.

You just proved my point by missing it, I'm impressed.

> Fahrenheit has nearly twice the integer resolution of Celsius. This is particularly helpful in describing body temperature.

Yet medical practitioners insist on using Celsius in the most of the world, what fools!

> 0 Fahrenheit is close to the typical minimum temperature, and 100 close to the typical maximum temperature, which can be tolerated by humans. Celsius 0 and 100 aren't even remotely close to this: it's surprisingly awful.

I am very rarely exposed to 0 F, in fact, I actively go out of my way to avoid it by seeking shelter during blizzards while on mountain tops.

You're more likely to encounter 0 F in a continental country, but in my temperate maritime climate country, a populated locale hitting -10 C / 14 F is big news, and only rarely would it get to -4 C / 25 F where I live. In other words, I have very little use case for 0 - 32 F.

So its intuitiveness to you, is opaqueness to me. Because you grew up with Fahrenheit, and I grew up with Celsius.

Scientists do use Celsius and Fahrenheit sometimes, unless your definition of scientist excludes everyone who isn't a chemist or physicist.

TL;DR - you prefer Fahrenheit because you think in it. I prefer Celsius because I think in it.

I think this is a theory of mind issue. You are used to Fahrenheit intuition and living in the US, so people arguing against your perception seem to be bikeshedding or being willfully obtuse/superior.

I can perhaps relate my subjective experience to better explain what's going on. I grew up with Celsius temperatures, so temperatures like 27C or -5C tell me exactly what I should wear when going outside. For Fahrenheit, even though we are told that it maps to human experience, I have to consciously try to remember what these 10F, 20F temperatures mean and often forget. The intuition just isn't there at all.

For height, I'm used to the metric system, but I can also understand the imperial system in that specific area because of seeing so many discussions about it over the years.

I actually learned to cook while in an Imperial zone, and now I am more used to certain temperatures in F.

The reason people find it shocking, is that we are essentially forced to deal against our will with Imperial measurements, because the US is a powerful country. The annoyance has more to do with the sensation of being trapped by another culture and having to adapt to their way of life rather than the reverse.

Pretty much the only reason I like the Fahrenheit scale, miles, inches and ounces seems to be that it’s something no one else uses. On the other hand, computers make calculations with these non-metric units just as easy, and precision-wise computers have no advantage to be taken from the base 10 anyway. (The fact that US is stuck with base 10 for numbers doesn’t mean much, as there always are ‘dozens’ and ‘scores.’)

Maybe your experience maps to the 0-100 Fahrenheit scale, but mine certainly doesn't. Temperatures where I'm from are typically 5-25C, 0-30C at the extremes. So 41-77, or 32-86. So how's Fahrenheit a more useful scale there? And what if you're from, I don't know, Bangkok? The temperature range there is, generously, 80-95F.

There are endless examples of where this argument doesn't stand up because the "averafe==ge human experience" is nothing like yours. But of course, it's more or less applicable in most of the US, so you imagine it's universal. Whereas, for the rest of us, 0 is cold, 10 is cool, 20 is warm, 30 is hot, and extrapolate from there. That's simple and relatable enough for me.

Another fun fact: meter was originally defined as a length of a pendulum whose half-period is one second.

But wait for it. If you look at the pendulum formula [1] you will realize that g ≈ π^2 (i.e. 3.14^2 roughly equals 9.8) is not a coincidence, it's a consequence of the original definition of the meter!

[1] https://www.google.com/search?q=pendulum+formula

That isn't correct. The pendulum definition was actually something called a "universal toise". Burattini suggested defining a unit called the metre based off of this, but it was found to be unworkable because it's not the same everywhere. A toise is ~1.949m.

The metre was _actually_ originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole. Obviously, that ended up having its own issues, hence the subsequent refinements until we settled on using the speed of light in a vacuum as the basis for it.

Nothing in what I said is incorrect. The original scientific definition of the meter is via a pendulum (1645), then it was refined via toises multiple times, and today it's defined via speed of light.

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

No, that's not correct, that unit while intended to be a universal measure of distance never was called a meter (the "inventor" wanted to call it "toise universalle"), all that comes from the wikipedia page you linked to, so the only remaining question is whether you can call it the "original definition".

I don't think you can call it the original definition, because (a) that definition never got any universal acceptance (not even among scientists), (b) didn't work (as it gave different results on different locations) and (c) wasn't particularly close in value to the current definition.

I understand, but the fun fact I mentioned, that the relation between pi and g is not accidental, stems from the earlier attempt to define the meter via a pendulum. Yes it was refined later many times, and it's why the relation between pi and g is not precise.

Except it has little to do with the metre other than being an earlier attempt at an objective measurement.

How does this size have anything to do with the metric system, it could have been any units of length with same ratio.

From the article: A0 is designed to be as close to 1m² as you can get with whole mm side lengths.

As such A1 is 1/2 m², A2 is 1/4 m², A3 1/8 m², A4 is 1/16 m².

I would call this tied to the metrics system. It never occurred to me that I could approximate odd 1m² areas with 16 sheets of A4... I found this enlightening from the original article. TIL.

Would recommend the documentary Precision: The Measure of All Things by Marcus du Sautoy. It's no longer on iPlayer but thankfully someone's uploaded it to YouTube.

https://www.youtube.com/watch?v=g81opjVDAaA

I could perhaps understand the use of fahrenheit for temperature - I'm not used to it, but people say the changes in different temperature degrees are more like how we perceive them (perhaps temperature is like some things like sound level that we perceive logarithmically, and ferenheit maps better to it [1]).

Not sure if this is valid (celsius looks fine to me) but if it is, sure, fahrenheit makes sense.

But for the rest, like distance and weight? What the fuck?!

[1] I'm not claiming we do perceive temperature logarithmically - just making an analogy with another case (sound) in which we don't use a straight linear relationship because it doesn't match our intuitive perception (e.g. of volume "doubling").

What do you mean? Fahrenheit is not logarithmic. The conversion function from Fahrenheit to Celsius is literallay a linear function: c(f) = f(5/9) - (160/9)

>What do you mean? Fahrenheit is not logarithmic.

It's not like I didn't explicitly cover that:

"I'm not claiming we do perceive temperature logarithmically - just making an analogy with another case (sound) in which we don't use a straight linear relationship because it doesn't match our intuitive perception (e.g. of volume "doubling")."

So, no, I'm not saying temperature perception is logarithmic and Fahrenheit is logarithmic to match it.

I'm just saying that similarly to how dB suits sound perception better (because it's logarithmic and more appropriate to our logarithmic perception of volume), fahrenheit might fit intuitive temperature perception better (because it's more appropriate to our perception of temperature).

Actually, I'm not even saying this is the case. Just that I've read and heard people claim that, so it could be (I'm not from a fahrenheit using country, so can't speal for how it intuitively feels), for one example:

https://thevane.gawker.com/fahrenheit-is-a-better-temperatur...

Fahrenheit is nice because the normal range of temps for most climates that humans generally prefer to inhabit is about 0 to 100. Over 100 starts to be dangerous to humans without some form of cooling, evaporative or otherwise. 0 F (-18 C) is about as cold a temp as most (not all) people would want to live in. Ironically, viewed from that perspective, Fahrenheit gives typical temps a nice powers of ten framework, which is normally one of the great advantages of metric systems. Celsius fails in this regard, going from -18 C to 28 C for the same range. Less precision and no intuitive decimal framework.

On the other hand, I completely agree that the rest of the non-metric measurements are just a mess. However, the binary nature of cups, pints, quarts, half gallons, and gallons are kind of quaint I suppose.

Shame this comment is floating to the top, for a few reasons.

First: The DIN paper standards aren't a part of the metric system. They are a use of the metric system.

Second, the important part: what makes A series paper cool (truly one of my favorite standards) is a ratio, these are by definition independent of metric.

One can imagine a paper standard based on 36 inches, rather than 1 meter, which would have all of the good properties of A and B series paper.

The third reason is that the imperial measurement system is also an application of the metric system. But others have covered that already.

It's an ongoing source of amusement to me that people fluent in just one system of measurement look down on a continent of hundreds of millions whose educated class is fluent in both.

Also the metre is a weird unit to use as a base. It is based on an incorrect 17th C estimation of the circumfrence of the earth and is now standardised as some weird fraction of the distance light travels in a vacuum in a second (a second itself being based on a weird fraction of transitions in a stable form of Cesium atom)

A foot is at least something very closely aligned across many cultures (from ancient Egypt to Japan) because of because of its clear and useful relationship to human scale and building products

> based on an incorrect 17th C estimation of the circumfrence of the earth

Incorrect? It's pretty bloody close for 1793 — The error is less than 0.02% !

> A foot is at least something very closely aligned

Hmm, the largest historic European foot listed on the corresponding Wikipedia page is almost 30 % larger than the smallest foot. So while they indeed all are somewhere roughly 30 cm-ish long, after a few feet those differences will still add up considerably…

I was a staunch advocate of the metric system, however, I am not the 'fanboy' I once was.

It all makes sense and seems really clever when you are at school with your little ruler with those weird inch things on the unused side. I could bark at any adult daring to use an outlawed measurement unit, to put them in their place.

To a certain extent we do that with Americans and their usage of 'weird' units that make no sense to people outside of the UK. However, as I have got older, I have learned to appreciate why these quaint measurements have survived the test of time. For example the 0.1 inch pitch spacing of integrated circuits is a gentle reminder that Americans pioneered and invented all of this stuff and that, despite the politics and sentiment of the time, some respect is deserved for the non-metric giant shoulders we stand on.

Every British person knows what a metre is but most British people will give their height in feet and inches. Ask those people what their height is in metres and your guess is as good as mine.

Weight has made a slow transition to kilograms in the UK. Stone is still a measurement. But when an American describes weight in pounds the average British person has not the foggiest.

I find more beauty in the vernacular measurements and I can play devil's advocate - 'Metric is French Napoleon conquest bad'.

Nowadays we have electronic gadgets to do the simplest arithmetic. Nobody does long division on paper these days. They don't even have a pen. The benefits of the decimal system are somewhat moot. I can see why base 12 measurements stick around but no idea why base 14 is a thing.

Anyway, couldn't the A4 problem have been solved with non square pixels?

It would be much more beautiful if it were based on 12 instead of 10. Of course, this would require humanity to switch to dozenal, which will never happen unless almost everyone dies and someone enforces it on the few that remain to repopulate the planet.

Could you expand why base-12 is more beautiful than base-10? Is it because it has more divisors? If so, why not base-2?

Yes, many more divisors than 10 which is divisible by only 2 and 5 but not by 3, 4, or 6. If you need to divide by 5 but not by 4, you can use 30, or if you need both 5 and 4, you can use 60.

Not worth getting worked up over. We will all be dead long before the USA widely uses the metric system.

I never realized this, but I’m glad I learned why this is.

It’s the kind of thing that you always wonder about but never seriously investigate.

You could go a whole lifetime without knowing…

I wish EU would force the manufacturers to advertise phone and TV screen sizes in centimeters, not inches.

It's not going to be helpful anyway, because the size is measured in diagonals, and it's quite difficult to imagine how large a screen is if you only have the diagonals.

If, instead, we had height and width, I can roughly use my body to estimate screen size.

Last time I bought a TV I had to tape out its size on my wall to get a better understanding of its size relative to the size of my living room.

As an American, I can say A4 feels just perfect to me. Not too large or small.

I'm still waiting for a thin low weight A4 size eink reader

Canadian here, I wish we switched to A* paper format :|

210x297 offers a better approximation than 212x300.

[curses in Tschichold]

This is very cool.

anomas01010

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