alt.hn

7/31/2026 at 3:00:15 PM

The most official water costs $120k a gallon

 https://signoregalilei.com/2026/07/26/the-most-official-water-costs-120000-a-gallon/

by surprisetalk

8/1/2026 at 1:15:50 AM

NIST Cigarettes are a mere $204 per carton.

Depending on what state you live in, that's not bad these days.

https://shop.nist.gov/ccrz__ProductDetails?sku=1196a&cclcl=e...

by Duanemclemore

8/1/2026 at 2:09:22 AM

Shows $508 for 2 cartons, so 254 per. NY has probably most expensive smokes, ranging $140-155 per carton

by VTimofeenko

8/1/2026 at 4:41:12 AM

Wont the state tax apply to the NIST ones as well?

by kalium-xyz

8/1/2026 at 2:02:05 PM

I checked by almost completing checkout and no state tax was charged. I would be surprised if the states could tax federal goods.

by skinfaxi

8/1/2026 at 2:31:59 PM

Generally states can't. I wonder if what could technically trip you up is the lack of tax stamps. But can you get in trouble for having unstamped cigarettes? I'd think generally no.

by bragr

8/1/2026 at 6:14:09 PM

The argument for "it shouldn't" could be that it's a federal supplier and/or some sort of RnD exception. Not sure if NIST would even sell to a private buyer.

by VTimofeenko

8/1/2026 at 3:05:29 AM

Australia is US$350-$400

by plaguuuuuu

8/1/2026 at 4:06:04 PM

Good, making them very expensive is one of the most effective ways to reduce smoking and all associated suffering, cancers, health costs, deaths.

by ornornor

8/1/2026 at 5:19:25 PM

And increase smuggling, black market, and risk of harm by consuming dubious quality products.

by throw1234567891

8/1/2026 at 5:26:10 PM

Much less than it discourages its use. Tobacco lobbies are fighting price increases tooth and nail, they wouldn't if it didn't work. Countries where the price has gone up have seen decreases in on-going consumption and new addictions. Countries where it's cheap (relative to local income) still have high level of smoking (and second-hand smoking).

by ornornor

8/1/2026 at 7:21:19 PM

Whatever, I like my cigarette.

by throw1234567891

8/1/2026 at 11:42:46 PM

Tobacco tax is actually crazy. I can get 200 cigarettes for $10 CAD from the natives because it's tax free.

by nish__

8/2/2026 at 10:22:37 AM

I heard from people. It is crazy, right?

by throw1234567891

8/2/2026 at 12:46:35 AM

No that’s stupid. It’s a tax on poor people.

by NuclearPM

8/1/2026 at 6:56:06 AM

Or retail at $15 per pack of twenty over-under the counter at your nearest “convenience” store, if it hasn’t been fire bomber over night in Melbourne, thought that seems to have eased off a bit since they arrested that guy.

https://www.dailymail.com/news/article-15975949/Melbourne-Je...

by perpetuallunch

8/2/2026 at 1:39:53 AM

USD190 in Norway

by unixhero

8/1/2026 at 2:43:06 PM

On the one hand, they say "for experimental purposes only," but on the other hand, hey, no cancer warning!

by bensyverson

7/31/2026 at 9:18:04 PM

most needs for such water are for calibration of instruments - many labs run stable isotopes measurements which has many applications from tracing how plants use water to measuring your metabolic base rate .. so the main use case it to calibrate instruments because it's really difficult to have an absolute measurement of stable isotope ratios from first principles - and the ratios are so small you typically express them in relation to standards like VSMOW

by jarenmf

8/1/2026 at 5:31:12 AM

Just remember that if you decide to brew up a cup from VSMOW you have to do it in strict conformance to ISO 3103.

by pseudohadamard

8/1/2026 at 7:00:15 AM

I prefer my tea brewed with SLAP, or more recently SLAP2.

by perpetuallunch

8/1/2026 at 1:57:42 PM

I wonder what's the standard for ethanol and, therefore, vodka.

by lstodd

7/31/2026 at 6:08:57 PM

Interesting article but left me wondering why they don't use ¹H₂¹⁶O as the "standard water"? Surely you can make that (relatively) easily in a centrifuge by spinning out the lightest fraction of water.

by rwmj

7/31/2026 at 10:28:18 PM

18 O enriched water is available to buy but the pricing suggests it's quite expensive to separate 16 O from 18 O. And you get much less variability in the ratio of isotopes from mixing compared to separating a single isotope as much as possible.

by barbegal

7/31/2026 at 7:02:00 PM

At the very least that has the advantage that it's possible to make more of it, so you aren't dependent on a limited sample of standard water.

by thayne

8/1/2026 at 12:06:27 AM

The article doesn't mention this, but they actually did make more. Or rather, they put together a new sample, VSMOW2, in 1999. It's exactly the same as VSMOW, to within measurement error. Like the original, you can buy it from the USGS. Documentation (including how it was prepared): https://nucleus.iaea.org/sites/AnalyticalReferenceMaterials/...

This actually goes both ways; VSMOW itself was carefully made (by mixing in small amounts of water from other sources) to match the composition of an earlier reference water sample, NBS-1, which came from the Potomac River (one supposes it was a convenience sample). NBS-1 is no longer used as a point of reference, since everyone's agreed to use VSMOW instead, but the USGS sells it too.

by ameliaquining

8/1/2026 at 9:10:14 AM

Just wait for the new reflecting pool standard of official water.

by cozzyd

8/1/2026 at 12:55:52 PM

Not an expert, but...

The use case for this water is calibrating ultra-precision instruments. The use case for those instruments is measuring water with normal-ish isotope ratios.

Calibrating your ultra-precision instruments to a point far away from their normal use case is asking for trouble.

by bell-cot

8/1/2026 at 12:37:27 AM

I at first thought you meant taking hydrogen gas and burning it in O18, which seems even simpler than bulk processing water.

by 0cf8612b2e1e

7/31/2026 at 4:56:15 PM

Reminds of me of the "most expensive peanut butter" at ~$2.44/g - sold by NIST, I assume for some sort of peanut butter factory process calibration: https://shop.nist.gov/ccrz__ProductDetails?sku=2387

by sudb

7/31/2026 at 6:45:42 PM

For more context, sample reference materials from the NIST reference catalogue are not meant to be exceptionally high purity examples of the sample -- SRMs are usually commercially-produced products. The real value is that each sample comes with a datasheet with incredibly detailed and accurate measurements that are (as you said) used for calibration of measuring devices in industrial settings. To quote a Veritasium video about the topic from a few years ago[1], "the thing you're paying for is not the peanut butter, it's the knowledge of exactly what is in the peanut butter".

[1]: https://youtu.be/esQyYGezS7c?t=226

by cyphar

7/31/2026 at 8:23:50 PM

Truth. I once paid nearly $500 for a set of 17 certified, calibrated wooden pencils, with documentation showing that each one met their rated hardness levels of 9H thru 6B. And for $500, they don't even come with erasers, that is an added-cost option.

https://www.gardco.com/product/pencil-hardness-test-kit-astm...

by buildsjets

7/31/2026 at 10:28:41 PM

I'd like to ask a more specific question than my sibling's excellent "Wait, why?" question :)

Why offer erasers on these things? The procedure described below has nothing to do with using these as pencils, and at $500 for a pack I can't imagine anyone, anywhere casually drawing with these.

(Is there another procedure, similar to the one described below, except instead of dragging the pencil tip across a surface you drag the eraser across it? )

by MikeTheGreat

8/1/2026 at 3:23:57 AM

I’d suggest you read “The TSO’d Pencil” to understand the reference.

Http://www.rstengineering.com/rst/articles/tsodpencil.pdf

by buildsjets

8/1/2026 at 8:26:48 PM

:)

I had no idea this reference existed, or that it's a a fun, though dystopian, read.

Thanks! :)

by MikeTheGreat

7/31/2026 at 9:09:18 PM

Can I ask why :-) Sounds like an interesting project.

by foobarian

7/31/2026 at 10:46:26 PM

You use the kit to test the harness of a finish coating, like a paint or a ceramic coating for cars. Pencils have their own hardness scale which can be used to gauge the hardness of the coating. Its really more of a relative qualitative test than quantitative as you'd use this for sample/coupon testing identical coatings. There are more absolute, quantitative methods to measure various hardness characteristics (scratch, indentation, and rebound). Like you'd use the pencil kit on a factory floor to make sure each paint sample performs the same, the sample being a small area on the product or a plate that's painted the same way.

by wildzzz

7/31/2026 at 11:20:59 PM

the pencil aspect is because its easy for a person to carry and take notes with?

and you dont need to fit the car into a proper harness tester?

by 8note

8/1/2026 at 12:53:14 AM

The pencil hardness scale is commonly used to assess paint film hardness by checking what is the softest pencil that can mar the surface when you scratch it with a given force. In this case, we needed to assess whether exposure to a certain chemical degraded the integrity of the paint coating that we were counting on for corrosion protection.

by buildsjets

7/31/2026 at 10:20:44 PM

His link includes procedures, which suggest he was testing the hardness of some surface coating or similar:

> For the pencil hardness test, reference ASTM D3363, pencils of increasing hardness values are moved over the surface in a precisely defined way until one lead damages the surface. Surface Hardness is defined by the hardest pencil grade which just fails to damage the surface.

> Observe the pencil track. Sufficient pressure must have been applied either to cut or damage the coating or to crush the lead pencil point.

> If neither coating damage or pencil point crushing is observed, repeat the test until a definite observation is made.

> If scratching or damage of the surface occurs, proceed with the next softer pencil grade and repeat the testing process until a pencil lead grade is found which crushes and does not damage the coating.

> If crushing of the hardest lead should occur, the coating is therefore extremely hard and is beyond the measuring range of this test

by cwillu

7/31/2026 at 5:25:47 PM

SRM 2387 pairs well with a cup of ISO 3103.

https://en.wikipedia.org/wiki/ISO_3103

by cjs_ac

7/31/2026 at 5:48:00 PM

Cap your meal off with a NIST 1196a standard issue cigarette? I am told they taste like drywall and taxes.

https://www.nist.gov/news-events/news/2020/02/nist-releases-...

Perhaps you would prefer some standard issue meat.

https://www.sigmaaldrich.com/US/en/product/sial/nist1546a

by buildsjets

7/31/2026 at 6:05:36 PM

A suggested product is "domestic sludge", lol. This is such a fun rabbit hole:

https://www.sigmaaldrich.com/US/en/product/sial/nist2781

by sushisource

7/31/2026 at 7:28:38 PM

Pretty much every process conducted at scale will have such reference samples.

by inigyou

8/1/2026 at 2:47:03 PM

New music genre just dropped

by bensyverson

7/31/2026 at 6:50:52 PM

It's only $508 per cigarette:

https://shop.nist.gov/ccrz__ProductDetails?sku=1196a&cclcl=e...

by tshaddox

7/31/2026 at 7:09:12 PM

That’s $508 for two cartons for 400 cigarettes total, so $1.27 per cigarette. They’re not characterized like the peanut butter, they’re just manufactured to a specific QC standard.

California/New York prices are easily $0.75/cigg so it’s not that much more expensive.

by throwup238

7/31/2026 at 7:08:12 PM

400 cigarettes actually! Not too bad.

by ryancw

7/31/2026 at 9:11:03 PM

Now I wonder what the GOST ones were like

by selimthegrim

7/31/2026 at 9:00:51 PM

I had seen the cigarette. But but not the meat which costs $2,690 for four tuna-can size cans and is a mix of pork and chicken

Thinking of a concept for a restaurant meal along the lines of a calibrated fried spam dinner, that costs ~2k for about a can worth, fried like they do in Hawaii.

Come to think of it, would love to see an “iron chef- calibrated foods” edition.

by andy99

8/1/2026 at 1:33:30 AM

"It was produced by ISO Technical Committee 34 (Food products), Sub-Committee 8 (Tea)."

by tedd4u

7/31/2026 at 7:27:11 PM

Yes, it’s a bit frightening to know what a hidden dependency NIST is on many things. In my industry, all calibrations ultimately derive from physical NIST standards for resistance, frequency, etc.

by georgeburdell

7/31/2026 at 8:02:54 PM

It’s frightening that… NIST is doing the very thing it was established to do back when it was called the Bureau of Standards?

by masklinn

7/31/2026 at 9:41:41 PM

I suspect the fear comes from both seeing NIST as a single point of critical failure, and perhaps also that it is a far less resilient and/or far more vulnerable, institution than may have been previously realized.

by GolfPopper

7/31/2026 at 5:54:32 PM

[flagged]

by juleiie

8/1/2026 at 6:30:26 AM

[flagged]

by DonHopkins

8/1/2026 at 5:48:16 PM

[flagged]

by juleiie

8/2/2026 at 12:57:57 PM

[flagged]

by DonHopkins

7/31/2026 at 5:43:50 PM

A US gallon of deuterium water costs roughly $2,600 to $3,800, while a gallon of pure tritium water (super-heavy water) would cost about $44 million.

by spullara

7/31/2026 at 9:26:41 PM

How much volume is that for the rest of the world? Really unscientific article.

by a3w

7/31/2026 at 9:47:47 PM 

   0.0001587302 hogsheads
   256 tablespoons
   231 cubic inches

by strictnein

8/1/2026 at 2:26:59 PM

Wouldn't 256 in proper tablespoons be 3840 ml?

by Ekaros

8/1/2026 at 6:18:57 AM

why do you consider the cubic inches will be useful to the rest of the world (world who does not use galons)?

by eimrine

8/1/2026 at 7:37:57 AM

Yeah, they should have stopped at hogsheads, which is a well understood quantity worldwide.

by sgerenser

8/1/2026 at 9:12:33 AM

Without cubic furlongs I don't have a good intuition for the amount

by cozzyd

7/31/2026 at 9:49:42 PM

Unless you're actually measuring something with any importance, a gallon is about 4 liters. More closely 3.78541... But saying a quart and a liter are about equal is often good enough.

by colechristensen

8/1/2026 at 1:48:01 AM

As long as you also know a gallon is 4.0… quarts

by tedd4u

8/1/2026 at 4:22:30 AM

quart = quarter ... gallon

by colechristensen

8/1/2026 at 5:56:50 PM

Wait till we learn what a fifth is!

by picofarad

8/1/2026 at 8:35:50 PM

That one I know: it's 750ml

by tedd4u

8/2/2026 at 1:56:08 PM

And five of them is 1% less than a gallon.

by colechristensen

7/31/2026 at 10:43:25 PM

Just think of the largest container of ranch dressing that you’ve ever seen in a grocery store. It’s that much.

by jrflowers

8/1/2026 at 4:33:28 AM

To be honest, if you live outside of the US the answer to that is more likely to be a liter (or less) than a gallon.

by bulbar

8/1/2026 at 5:05:54 AM

In that case you can imagine the biggest container of ranch dressing you’ve ever seen in a grocery store, a gallon is a few of those

by jrflowers

7/31/2026 at 10:25:41 PM

I get your point but unless you actually need tritium water the number still means nothing lol.

by ajs1998

8/1/2026 at 11:03:52 AM

1 gallon is 0.832674 gallons. Or 1 gallon is 1.20095 gallons.

by fredoralive

7/31/2026 at 6:25:12 PM

Makes me want to go to the ocean and start filtering out water somehow.

by BizarroLand

7/31/2026 at 7:32:50 PM

You can centrifuge it. Heavier molecules move closer to the bottom. Repeat until you reach the desired purity.

You need shitloads of ordinary water to extract a liter of heavy water. And I'd be surprised if there's any superheavy water in that, because tritium radioactively decays.

Fun fact: Heavy water is slightly toxic to humans. If you only drank heavy water, you'd die as it shifts the chemical reactions in your body out of balance. A moderate amount is fine though.

by inigyou

8/1/2026 at 12:41:25 AM

Emphasis on the slightly. I believe it would take weeks of only consuming heavy water. You could certainly drink a single glass of it without ill effects.

by 0cf8612b2e1e

7/31/2026 at 10:53:50 PM

IIR, a number of rich & famous people have developed severe mercury poisoning after extended conspicuous consumption of swordfish and other very expensive/very contaminated seafood.

Obviously the luxury bottled water industry is missing out on the potential of D2O and T2O.

by bell-cot

8/1/2026 at 4:21:48 AM

they're making medicines now with deuterium to alter the half-life

by fnord77

8/1/2026 at 2:22:11 PM

Deuterium or tritium? Deuterium is a stable isotope and does not decay.

by woadwarrior01

8/1/2026 at 8:17:58 PM

Probably deuterium. Half-life doesn't only mean radioactive decay, it also means the rate at which a medication is broken down or excreted from the body. Tritium is more likely to be used as a radioactive tracer.

by inigyou

7/31/2026 at 7:36:52 PM

Another fun fact - heavy water has a sweet taste.

by danbruc

7/31/2026 at 9:07:07 PM

How did someone ever figure this one out?

by htrp

7/31/2026 at 9:30:34 PM

Probably by drinking it. As I said, it's only slightly toxic. Cody's Lab has done it on YouTube. 0.01% of the normal water you drink is heavy water.

by inigyou

8/1/2026 at 2:04:22 PM

I hadn't put much thought into why it was called "Vienna Standard Mean Ocean Water".

My first hint should have been that Austria is landlocked.

by extraduder_ire

7/31/2026 at 9:43:30 PM

Slap the 'organic' label on it and sell it at restaurants for $150k/L. It will sell.

by 1970-01-01

7/31/2026 at 6:24:57 PM

How does the water taste?

by cactusplant7374

7/31/2026 at 10:04:20 PM

Completely decadent, with only a slight aftertaste bearing a noticeable hint of regret . . .

by fuzzfactor

7/31/2026 at 11:27:28 PM

like what you most want but most can’t have, and what you most can’t have is what you already once had, but lost.

by deadbabe

8/1/2026 at 1:15:03 PM

Does NIST have a restaurant?

by rainmaking

8/1/2026 at 12:54:23 AM

Idk I feel like if you bought in bulk you would get a discount on the additional mL purchased.

by fionic

7/31/2026 at 11:33:42 PM

I can't help but read VSMOW as Very Standard Mean Ocean Water.

by tomsmeding

7/31/2026 at 5:16:12 PM

This is why we should ditch Celsius for Kelvin. I never liked how we coupled 0 and 100 to where water freezes and boils under certain conditions. Kelvin doesn't rely on non-invariant reference points.

by artisinal

7/31/2026 at 6:03:11 PM

You want numbers to be understandable and K produces illogical numbers.

(There is a reason it is common to drop the century when talking about years, humans are less skilled at numbers over 100)

And I know temperatures in Fahrenheit go higher but it is common to refer to Phoenix as "over 100" even when it's high can peak over 120.

by Guvante

7/31/2026 at 6:21:50 PM

That’s 02025 thinking.

by zinckiwi

8/1/2026 at 2:19:43 PM

You mean 0o2025 that is 1045AD?

by lstodd

7/31/2026 at 9:45:23 PM

X̅ ?

(I'm a little sad the five-digit date hasn't become popular.)

by GolfPopper

8/1/2026 at 3:08:26 AM

Why would five-digit years have become popular? They seem roundly a bad idea.

Years aren’t even four digits by custom: they’re just numbers, with the present idiosyncrasy of eschewing a grouping (thousands) separator. We say the sack of Rome was in 410, not 0410. Only for specific serialisation purposes have we ever recorded fixed-width dates, acknowledging that there are limits to this. The recording of two-digit or offset-by-1900 years in computer systems was a case of bad judgement. The recording of four-digit years as is presently customary is pragmatic and entirely adequate for the next few thousand years, and there’s no point in designing things beyond that horizon.

by chrismorgan

7/31/2026 at 6:41:58 PM

> (There is a reason it is common to drop the century when talking about years,

Yep.

> humans are less skilled at numbers over 100)

No, the reason is that the century is constant and therefore carries no information. Where the century isn't constant, it never gets dropped.

by thaumasiotes

7/31/2026 at 7:52:58 PM

You can say the same thing about decades

No one says 6 even though it has a very reasonable information density for conversations. It is either a relative year or a two digit one.

by Guvante

7/31/2026 at 10:33:50 PM

The 90s called, they'd like a word.

by cwillu

7/31/2026 at 11:24:31 PM

what makes a number illogical? i havent heard of that concept wrt to numbers

by 8note

8/1/2026 at 4:04:41 PM

Paraphrasing for "hard to understand" but with an emphasis on internalizing.

Most people generally fundamentally know what 30 means in their unit but might have a harder time with 303 (or 272)

by Guvante

7/31/2026 at 5:55:11 PM

Kelvin does still rely on each degree being 1% of the way between freezing and boiling so it kinda does rely on a variant reference point

by xgulfie

7/31/2026 at 5:59:43 PM

The reference point is the triple point, and invariant.

by chermi

7/31/2026 at 7:26:54 PM

Sure technically yes, but also celsius is now technically defined as just Kelvin plus 273.15. Degrees have technically been redefined as exactly 1.380649×10^−23 joules

by xgulfie

7/31/2026 at 8:28:08 PM

Why is that only "technically yes"? It's precisely how the thermodynamic and empirical temperature scales are matched.

by chermi

8/1/2026 at 10:13:04 AM

tripple point of what tho?

which water?

by NooneAtAll3

8/1/2026 at 6:55:34 PM

Wut? Water. H20.

by chermi

7/31/2026 at 6:11:57 PM

this is actually why i like fahrenheit the most... 0F is "really cold" and 100F is "really hot", whereas in celsius 0C is "kind of cold" and 100C is "uninhabitable". it makes sense for the 0-100 range to be reserved for temperatures frequently encountered in our habitat as humans i think...

by warmdarksea

7/31/2026 at 7:17:18 PM

That’s a biased view that leads to a scale only convenient for people living in particular latitudes. Now talk to someone living near the equator like Singapore, and 0F is unimaginably cold (even 40F is basically unheard of), and 100F is very hot but not extraordinarily so. Then you talk to someone living close to the arctic and the converse is true.

All this talk about 0F to 100F being frequently encountered probably reveals your local climate conditions more than it helps define a useful global standard for all humans. We should accept that humans live in more diverse conditions than we intuit and such a scale probably won’t be useful for all.

by kccqzy

7/31/2026 at 7:29:42 PM

Now I'm imagining some kind of timezone-like temperature unit that varies around the world, and a "100 things programmers should know about ___" post about all the intricacies and special cases.

by cyral

7/31/2026 at 11:28:16 PM

Ooh, and it could shift seasonally so that summer temperatures and winter temperatures can both be in the convenient range. And every locality could shift a different amount and at different times of year according to their local climate.

Next, we can look into reforming those pesky mass and volume units…

by wiml

8/1/2026 at 12:00:20 PM

I cannot wait for leap degrees.

by kergonath

8/1/2026 at 2:28:49 AM

Where I live now (Hyderabad, India), the record low is about 45°F, the temperature will not drop below 50°F more than two or three days in a year, and the daily maximum will not drop below 100°F for at least fifty consecutive days in the summer.

by chrismorgan

8/1/2026 at 1:27:17 AM

> Now talk to someone living near the equator like Singapore, and 0F is unimaginably cold (even 40F is basically unheard of), and 100F is very hot but not extraordinarily so.

Bad example--Singapore has never had a single 100F day in recorded history. The highest temperature ever recorded was 37C/98.6F. As a small island its climate is greatly moderated by the masses of water around it. It rarely gets above 90F.

The broader point about the 0-100 Fahrenheit scale being convenient for people from a certain climate is correct, of course.

by CrazyStat

7/31/2026 at 9:56:50 PM

> That’s a biased view that leads to a scale only convenient for people living in particular latitudes

I mean, the other option is cool vs dead

> We should accept that humans live in more diverse conditions

The second most diverse range of temps in the world is smack dab in the middle of the US: South Dakota up through northern Minnesota. Most years that area experiences -40F in the winter and 110F in the summer.

by strictnein

7/31/2026 at 6:20:10 PM

Celsius maps nicely to the temperatures observed in a typical Finnish sauna. 100C is among the highest typical sauna temperatures (very relaxing in dry air), and afterwards you cool off with water around 0C

Also, having 100C as water temp for black tee and 80 for green tee is nice to remember

by wongarsu

7/31/2026 at 6:33:03 PM

This has always been my primary argument in favor of Fahrenheit. It makes sense for humans, which is all a majority of the population really cares about. In addition, it's more granular. Sometimes turning the thermostat up or down by 1C could be too much, where 1F is just right.

In science and math, I can see where having round numbers for commonly used temperatures would be useful, but if 0C and 100C are the only places that happens, it's not that hard to memorize 2 numbers.

by al_borland

7/31/2026 at 7:39:40 PM

You only think it makes sense for humans because it makes sense for you, where you live the same way you feel changing a thermostat by 1F is perfect but 1C is too much: that’s true for you, not universally.

Fahrenheit functionally requires you to be biased in order for it to seem like a good system.

by Timpanzee

7/31/2026 at 7:52:47 PM

It provides greater granularity in the range of human comfort, without descending into decimals. How is that not more useful for day-to-day human usage?

0F is cold, 100F is hot. I experience both of these temperatures outside where I live every year.

-20C to 40C seems much more arbitrary as a way to measure the zone humans mostly live in.

I would wager that the outdoor and room temperature are an overwhelming majority of human use for temperature. It seems like it would make sense to optimize for how temperature is more commonly used at a population level.

I would say those who see Celsius as a good system are also biased, because they grew up with it and it’s what they’re used to.

by al_borland

8/1/2026 at 1:30:43 AM

> 0F is cold, 100F is hot. I experience both of these temperatures outside where I live every year.

This is just your location, and things like this vary around the world a lot. Hell, they vary in the US. To me, where I live (in the US), 0F and 100F aren't really useful as benchmarks; we don't see either of those temperatures here, ever. The normal range is more like 40F-80F (with extremes maybe down to 25F and up to 90F, but those numbers push credibility a bit).

But ok let's look at averages. Do "most humans" (whatever that means) really live within 0F to 100F? That doesn't really pass the smell test for me; there are lots of humans who live in places where it regularly exceeds 100F. And in those places I doubt it gets anywhere near 0F, with many places never getting down to even 20F. There are also lots of places that get warm, but will never see 100F, and seldom see 90F.

It's all super super arbitrary.

Having said that, I still prefer F over C, but I don't pretend there's any rational reason for it: it's just because I grew up with Fahrenheit, and no matter how hard I try, I just can't feel Celsius the same way. I feel like you maybe don't interact with too many people who grew up with Celsius; you'd probably realize they feel the same way about C as you do about F, and that there's no rational reason for it. It's just what you were trained to think and feel in, and it stuck.

by kelnos

7/31/2026 at 8:10:42 PM

> 0F is cold, 100F is hot. I experience both of these temperatures outside where I live every year.

Most people never experience anywhere near 0F in their lives.

> -20C to -40C seems much more arbitrary as a way to measure the zone humans mostly live in.

The zone most humans live in does not routinely (if ever) get anywhere near -20, to say nothing of -40.

by masklinn

7/31/2026 at 9:02:34 PM

The -40C was a typo, should have been 40C, to mirror the 0F to 100F, rounding a bit to make it less silly. It’s been fixed now.

Millions do experience 0F, and it’s ok to not use the full range. At or around 0F is cold, as you move closer or beyond it, it’s cold. As you move closer to or beyond 100F, it’s hot. Most people would likely prefer to never deal with <0F or >100F.

by al_borland

8/1/2026 at 1:34:12 AM

Millions -- hundreds of millions, even -- regularly experience -10F and 110F as well, but you've arbitrarily picked 0F-100F, so I guess their experience doesn't matter, because you prefer round numbers?

by kelnos

8/1/2026 at 5:24:16 AM

> Millions do experience 0F, and it’s ok to not use the full range.

That’s not even an argument. Billions never experience freezing temperatures let alone 0F, and it’s ok to use negative numbers.

> At or around 0F is cold, as you move closer or beyond it, it’s cold.

The exact same statement can be made about 0C. Hell if you live in a subtropical area 10C is cold.

> Most people would likely prefer to never deal with <0F or >100F.

Most people would likely prefer to never deal with < 15C or > 30C.

by masklinn

8/1/2026 at 6:07:26 PM

Human body temp is nearly 100°F and a freezer routinely is around 0°F.

Can we stop arguing now?

by picofarad

8/1/2026 at 6:05:52 PM

I experienced 3°F in the subtropics and it is probably about 100°F outside right now. Average winter temps of 35° with only 1-7 days of actual frost, usually around christmas. (Dec 25(December 25))

by picofarad

8/1/2026 at 12:36:10 AM

> you feel changing a thermostat by 1F is perfect but 1C is too much: that’s true for you, not universally.

I've noticed that here in Japan all the AC units seem to be adjusted by half a degree Celsius at a time, so I do think 1C is a bit much even for people who never used fahrenheit.

by tdeck

8/1/2026 at 12:04:32 PM

The good thing is that there is nothing preventing anyone from adjusting their thermostat with a decikelvin precision. Or hell, even centikelvin if they’re pushing it.

by kergonath

8/1/2026 at 1:21:38 AM

Every non-US thermostat I've seen that works in Celsius is adjustable by half-degrees, so it seems the manufacturers agree with my feeling there...

by kelnos

8/1/2026 at 2:15:31 AM

Living in Australia and India, I have never encountered such a thermostat. But I do vaguely recall encountering a thermostat somewhere at some point that went up by twos in Fahrenheit.

I would guess you would only encounter ½°C steps on units that support both Celsius and Fahrenheit, so that they’re closer to parity. I don’t think any unit that I’ve owned has supported Fahrenheit at all.

by chrismorgan

8/1/2026 at 1:47:57 AM

Actually, 1 degree of Fahrenheit is the amount of temperature change a typical human can connect. It's a human-calibrated scale.

Though why 32F instead of 0F for frozen water...I have no idea.

by bananamogul

8/1/2026 at 2:20:30 AM

> 1 degree of Fahrenheit is the amount of temperature change a typical human can connect

Citation needed. https://en.wikipedia.org/wiki/Fahrenheit suggests no such thing, nor have I ever heard the notion.

by chrismorgan

8/1/2026 at 2:32:18 PM

Because lower point is temperature of certain chemical reaction. And upper end is body temperature... Oh wait... Yeah it is bad scale.

by Ekaros

8/1/2026 at 5:48:37 AM

I can't express just how profoundly culturally biased this is. There is absolutely nothing about Fahrenheit that 'just makes sense' to someone who grew up with Celsius instead.

Your comment about granularity is also nonsensical. I can adjust my heating by more granularity than 1C. That has literally nothing to do with the units being used.

by bigDinosaur

8/1/2026 at 8:12:04 AM

As someone who has used Celsius all my life, I actually kinda think they have a point here - where I live temperatures range from -10 to 39 in Celsius, and our home thermostats have 0.5 degree increments. Had we used Fahrenheit it would be a more human-friendly and compact-display-friendly 11-99 with little need for the fractional part.

-10.5 = 5 characters 11 = 2 characters

by plibblr

7/31/2026 at 7:23:48 PM

Celcius is pretty intuitive actually. It takes atmospheric pressure into account, Water is pretty abundant on the surface of the planet, and life kinda depends on it. It's a remarkable substance and quite stable. I dont think theres another substance where we can see all three phases with kitchen appliances and still consume it. Equally good for bathing and drinking. I need steam to clean clothes and cook my food. Using water as a benchmark for how we measure temperature is remarkably useful.

by vagrantJin

7/31/2026 at 7:40:58 PM

With all of those examples, the actual temperature doesn’t really matter.

For drinking and bathing, people go by feel. In the kitchen, the freezer makes water freeze, and the stovetop will make it boil into steam, but exact temperatures aren’t really relevant here either. The same goes for ironing clothes, the iron just does it.

When I think about where explicit temperatures are needed in the home, the oven and thermostat are the two things that come to mind. Water is pretty irrelevant for both of those. For cooking or frying someone may monitor meat or oil temps, but those aren’t water. A hot tub might have an actual temp on it, but those tend to be around 100F, not 100C, as they are meant for humans, not boiling.

Water is an amazing liquid, but I still struggle to see how measuring all our temperatures based on it makes sense.

by al_borland

8/1/2026 at 1:37:30 AM

> For drinking and bathing, people go by feel.

Yes, and people who grew up with Celsius feel in Celsius, and people who grew up with Fahrenheit (like myself) feel in Fahrenheit.

Stop trying to make some sort of determination of what's logical or reasonable here. Neither one is more or less logical than the other for day-to-day layperson use; anyone can "feel best" in any scale if they were taught it at a young age and used solely that scale for the formative years of their lives. Hell, I bet you could make a kid feel in Kelvin if that's all they were exposed to for their childhood. Or in some made-up scale that takes your 0F-100F and compresses it inside 22-35.

by kelnos

8/1/2026 at 1:31:52 PM

When I said drinking and bathing go by feel, I meant that they aren’t measuring the temperature, so the units are irrelevant.

When drawing a bath, I don’t get out a thermometer, I just stick my hand in the water and feel if it’s comfortable. C, F, or K… who cares? It doesn’t come into play.

by al_borland

7/31/2026 at 9:14:15 PM

> When I think about where explicit temperatures are needed in the home, the oven and thermostat are the two things that come to mind.

But in that case in what way is for example baking a frozen pizza from the store at 400 to 425 degrees F more relatable/convenient/natural than 200 to 220 degrees C?

by QuantumNomad_

7/31/2026 at 10:08:28 PM

It's not. When it comes to an oven, F and C are equally arbitrary, so it really doesn't matter. Optimize for what people use most, and let the other random uses fall as they may.

by al_borland

8/1/2026 at 1:41:40 AM

You have it backward. There's no absolute truth on what's optimal for what people use most. What's optimal is just what you were reinforcement-trained to feel when you were growing up as a child. That's it.

My wife says "30C" and knows exactly how that feels, while I struggle to find a reference point. I say "86F" and know exactly how that feels. Even though she prefers C, she can feel F slightly better than I feel C, as she moved to the US when she was in her teens. (Whereas I've spent my entire life in the US, outside of business and holiday travel.)

by kelnos

8/1/2026 at 12:02:26 PM

> It makes sense for humans, which is all a majority of the population really cares about.

The Celsius scale makes perfect sense to me and the vast majority of humans in the world. Much more so than the Fahrenheit scale, which I absolutely never use. That’s not really a strong argument.

by kergonath

7/31/2026 at 6:16:17 PM

This makes sense if weather is the main focus. For things like cooking Celsius is great though.

by ajmurmann

7/31/2026 at 6:53:39 PM

I am failing to understand why there would be a distinction. They all seem arbitrary set points you learn.

450F vs 230C does not feel like anything gets easier there. Maybe in some highly technical baking there are some nice deltas that appear?

by 0cf8612b2e1e

7/31/2026 at 6:54:02 PM

Aren’t you just remembering specific numbers though? Unless you’re trying to boil water unseen so that you can only see a thermometer, the specific 100°C mark isn't that useful.

by clickety_clack

8/1/2026 at 1:45:00 AM

> Aren’t you just remembering specific numbers though?

That's the thing about this. It's so tiring for people to argue which temperature scale is "better". Nothing is better or worse. What's "better" is individual, and is just "what you grew up with". Because right, you're just remembering specific numbers, and remembering how those temperatures feel. (Or in the case of cooking, remembering what those temperatures do to your food.)

> Unless you’re trying to boil water unseen so that you can only see a thermometer, the specific 100°C mark isn't that useful.

Even then it's not that useful, as water doesn't really boil the way most people think it does. (And god forbid you aren't at sea level and aren't at standard temperature and pressure.)

by kelnos

7/31/2026 at 9:07:04 PM

The temperature water boils at is irrelevant when you can just look at it to see if it’s boiling. Any stove will get it hot enough, assuming you have enough energy.

by quickthrowman

8/1/2026 at 1:47:34 AM

Also if you set something to heat water until it's exactly 100C/212F, it probably won't be boiling when it gets there. Some bits of it might be bubbling, but it won't be what we normally think of as "boiling".

by kelnos

7/31/2026 at 7:13:06 PM

OF will still kill you faster than 100F, and most folks aren't comfortable at 50F.

It inspires the following idea: A nonlinear scale where ~72F is 0, and +X represents the same level of heat discomfort as -X represents cold discomfort.

by Paracompact

7/31/2026 at 11:26:48 PM

thats a very location dependent scale.

youd still need to include where the discomfort is measured

by 8note

7/31/2026 at 8:52:02 PM

Haha, judging by my personal standards, we need to set the zero to 15 C and the 100 to 40 C. My Degrees Arjie are going to be a revolution.

by arjie

7/31/2026 at 6:50:42 PM

I actually came around to Fahrenheit for the exact same reason. 0°F and 100°F are kind of the top and bottom of the temperature range I’m going to be experiencing and anything outside that is waaay too hot or cold. In Celsius a large portion of people have to flip to negative numbers regularly during the normal year, and everything between 45°C and 100°C is completely unused.

by clickety_clack

8/1/2026 at 2:00:25 AM

I dunno, temperature doesn't really work like that. As a sibling mentioned, saunas: I can sit in a 190F dry sauna for about a half hour at a time and it feels hot but nice and soothing. But I can only handle a 120F steam room for maybe 10 minutes before I need to get out of there. (Speaking of the dry sauna, if someone pours a bit of water on the stones, it near-instantly feels significantly hotter, even though the temperature hasn't changed.)

Put another way, I can sit in a 190F sauna for a half hour, but a half hour out in the sun in, say, Singapore, feels awful to me. 85F where I live now (unusual but happens), in a relatively dry climate, is bearable, while the same temperature where I grew up, in a much more humid place (where it was more common), feels gross and saps my energy.

And I can be out snowboarding in 25F weather that's calm and sunny, and feel fine in a medium-weight clothing. But add clouds and wind, at the same temperature, and it's unbearable.

And to me, based on the temperatures I usually see, 15F is waaay too cold, and 90F is waaay too hot. Sure, I guess I could round that down to 100F and up to 100F, but that just feels like being arbitrary for the sake of easy numbers.

by kelnos

7/31/2026 at 7:34:23 PM

> 0°F and 100°F are kind of the top and bottom of the temperature range I’m going to be experiencing and anything outside that is waaay too hot or cold.

Food, saunas, the weather, a fever, and much more are often over 100F.

by mmooss

7/31/2026 at 6:21:53 PM

Also for things like hvac temps Celsius is rather too coarse where as 1F is right around the perceivable difference.

by TylerE

7/31/2026 at 6:48:38 PM

There's nothing stopping the use of decimal points for Celsius. Though there's also nothing stopping decimal points in Fahrenheit, the rare instance where an imperial sub-unit doesn't make things go fucky.

by SketchySeaBeast

7/31/2026 at 7:34:04 PM

Except 0F being “really cold” and 100F being “really hot” is a personal bias of yours based on where you’ve lived. It’s not true for everyone or everywhere.

And even if it were true, it still wouldn’t work. 100F in a dry environment is nice while, in a humid environment, 100F is awful. Same for 0F, a dry and static 0F is fine while a wet and windy 0F is killer.

by Timpanzee

7/31/2026 at 10:04:10 PM

What's a "wet and windy" 0F? It's more or less a physical impossibility. 0F air can't hold much moisture. Also, it's not a killer.

by strictnein

8/1/2026 at 12:51:04 AM

Experience 0F wind in central North America or Central Asia vs 0F wind on the coast and tell me it’s not different. Also, it’s killer, not a killer, as in it sucks a lot.

by Timpanzee

8/2/2026 at 11:22:50 PM

There's still almost no moisture in the air at 0F, no matter if you're on the coast are in the middle of the continent. The air just can't hold that much water at that temp.

When it's warm:

   50% humidity @ 40C: 25.43 g/kg (grams of water / kg of air)
   90% humidity @ 40C: 45.78 g/kg
When it's cold:

   50% humidity @ -18C (~0F): 0.68 g/kg
   90% humidity @ -18C (~0F): 1.23 g/kg
There's just not enough there to cause any noticeable affect.

But you don't have to take my word for it, the US National Weather Service agrees:

https://www.weather.gov/safety/cold-wind-chill-chart

"The results of the tests showed that relative humidity was an insignificant weather parameter, affecting the outcome to less than 1 degree"

by strictnein

7/31/2026 at 5:53:00 PM

I think that both the Celsius and Fahrenheit scales are now defined in terms of Kelvin and a formula. Most if not all of the units of measure are no longer related to their history except for an agreement to make the new units match the old ones at some point.

by analog31

7/31/2026 at 6:55:36 PM

The US is technically metric in that the units are defined in terms of the metric equivalent. A US inch is exactly 2.54cm.

by 0cf8612b2e1e

7/31/2026 at 9:12:03 PM

You can thank Carl Edvard Johansson[1] for that, the inventor of the gage block.[2]

He was the one who decided to make it a convenient value, according to Wikipedia[3]

  As a result of the definitions above, the U.S. inch was effectively defined as 25.4000508 mm (with a reference temperature of 68 degrees Fahrenheit) and the UK inch at 25.399977 mm (with a reference temperature of 62 degrees Fahrenheit). When Carl Edvard Johansson started manufacturing gauge blocks in inch sizes in 1912, Johansson's compromise was to manufacture gauge blocks with a nominal size of 25.4mm, with a reference temperature of 20 degrees Celsius, accurate to within a few parts per million of both official definitions. Because Johansson's blocks were so popular, his blocks became the de facto standard for manufacturers internationally, with other manufacturers of gauge blocks following Johansson's definition by producing blocks designed to be equivalent to his.
This makes it relatively easy to handle making metric threads on imperial machines, and vice versa, because you can use 50 / 127 gear tooth pairs to do the ratios.

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

[2] https://en.wikipedia.org/wiki/Gauge_block

[3] https://en.wikipedia.org/wiki/Inch#History

by mikewarot

8/1/2026 at 1:34:23 AM

An odd little factoid: A metalworking lathe will usually have a mechanism for cutting screw threads, with a multi-ratio gearbox for linking the rotation of the spindle to the motion of the carriage. For cutting metric threads, you have to change a pair of gears. So there will be a pair of gears with 50 and 127 teeth, which produces the 2.54 ratio. Then you have to look up the correct gearbox settings for each metric thread pitch in the manual. [0]

It's a big royal pain in the arse, and I've never had a machinist agree to turn metric threads on a lathe. They would rather wait a day and order a metric tap or die. Nowadays the CNC lathes just do it auto-magically.

Also, among old bicycles, there are some weird national thread standards that had metric diameters but inch thread pitches, because of machinery imported into countries like Italy and France during reconstruction after WWII.

[0] Edit: Just noticed duplicate comment preceding mine.

by analog31

8/1/2026 at 8:58:08 AM

Strange statement to say in an article specifically about water, of which both the Kelvin and Celsius derive their scale.

by fps-hero

7/31/2026 at 6:22:15 PM

Now do metric vs imperial.

by throwatdem12311

7/31/2026 at 6:26:31 PM

Nothing screams freedom more than using ancient terms like horsepower and measuring tires in inches and percentages.

The other day I heard an American talk about a TV being 65 inches. Took me a while to understand they had a 165 centimeter diagonal television.

by artisinal

7/31/2026 at 8:02:38 PM

Speaking of tires, its actually a crazy mixture of units here in the US. You might have a size like P215/65R15 which translates to a radial passenger tire of a 15" rim, 215mm wide tread (sidewall to sidewall), and an aspect ratio of 65 which is a ratio of the sidewall to tread width.

So a tire size is expressed in inches, millimeters, and ratios.

by vel0city

7/31/2026 at 7:49:50 PM

most tv makers and electronics stores in europe give you the screen size in inches first and cm second. they only come in a few common sizes so the specific units dont really matter.

by tancop

8/1/2026 at 4:09:57 PM

I’m Canadian and we’re mostly on metric but due to our proximity to the USA we use imperial for things like tires and TVs and it’s kinda silly but I’m used to it

by throwatdem12311

7/31/2026 at 7:02:37 PM

I bet you’d use lightyears over petametres or exametres though.

by clickety_clack

7/31/2026 at 7:16:41 PM

It's more typical to use parsecs in practice for astronomy.

by Alpha3031

8/2/2026 at 11:20:14 PM

yeah, and imagine living without decameters and hectometers, unthinkable!

by fsckboy

7/31/2026 at 6:54:28 PM

Surely you mean tyres? It’s all arbitrary. Get over yourself.

by alehlopeh

8/1/2026 at 10:12:09 AM

kelvin still has reference points - absolute zero and tripple point of water

good luck choosing which water, tho

by NooneAtAll3

7/31/2026 at 5:25:48 PM

As specialized world-class lab supplies and reagents go, that is not very expensive. Stuff like pure Xe (for space thrusters) can be more by mass.

by sandworm101

8/1/2026 at 12:12:33 AM

Yeah, but people find it perfectly intuitive that things like xenon are expensive because the material itself is rare; that kind of scarcity is a thing humans have dealt with since the Stone Age. Whereas this stuff is just water.

by ameliaquining

8/1/2026 at 6:09:38 AM

Rarity isn't really an issue when buying laboratory quantities. Purity drives the price.

by sandworm101

7/31/2026 at 4:43:57 PM

Loved reading this. Thank you!

by pack_stimulus

8/1/2026 at 1:51:38 AM

So to fill a typical 20,000-gallon pool with this water would cost $2.4 billion.

That might even give a trillionaire pause.

by bananamogul

7/31/2026 at 6:01:33 PM

gallon is not a si unit ;)

by dorianmariecom

7/31/2026 at 5:02:42 PM

[dead]

by alanfalcon

8/1/2026 at 12:25:26 AM

I got mine at a NIST surplus sale for just $55k/gallon. I think it was mismarked.

OK I just made the whole story up

by tomcam