Science desk
< October 26	<< Sep \| October \| Nov >>	October 28 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

October 27

What is a pound intended to approximate?

We all know that a kilogram is intended to approximate the mass of a quantity of liquid water equal in volume to a cube whose side is one-tenth of a meter. But, what is a pound intended to approximate? Why does a pound weigh what it does? 2601:18A:C500:7170:4130:25A7:7F43:F0D6 (talk) 06:48, 27 October 2022 (UTC)[reply]

Pound (mass) is your starting point. -- Jack of Oz ^{[pleasantries]} 07:18, 27 October 2022 (UTC)[reply]

Actually, while the kilogram was originally defined as the mass of one litre of water (and not as an approximation), that's not how it is defined today. See that article for details. Mike Turnbull (talk) 11:03, 27 October 2022 (UTC)[reply]

There is a little aphorism "A pint is a pound, the world around hinting at the (approximate) original definition of a pound and/or a pint. --Jayron 32 12:47, 27 October 2022 (UTC)[reply]

Yes, and "a pint of water is a pound and a quarter", meaning its weight not its price is actually still factually accurate in the UK. Mike Turnbull (talk) 14:08, 27 October 2022 (UTC)[reply]

A pound avoirdupois is 7,000 grains, so presumably it was intended to approximate to the average weight of 7,000 grains. The grain is important, because its weight is the same in all three weights (Avoirdupois, Troy, Apothecaries), which cannot be said of e.g. pounds and ounces. 2A00:23C3:9900:9401:C9B1:FD0D:3185:3358 (talk) 15:13, 27 October 2022 (UTC)[reply]

The "pound and a quarter" comes from the use of the imperial pint, based on 20 fluid ounces, rather than the standard American pint, based on 16 fluid ounces. An imperial pint of water does indeed way about 1.25 pounds, whereas a standard American pint of water is about 1 pound. --Jayron 32 15:20, 27 October 2022 (UTC)[reply]

And is why I prefer drinking in British bars! Mike Turnbull (talk) 15:35, 27 October 2022 (UTC)[reply]

"whereas a standard pint of water" - very parochial! I think you mean to say: "An imperial pint of water does indeed weigh 1.25 pounds, whereas a US pint of water is 1 pound". Martin of Sheffield (talk) 16:16, 27 October 2022 (UTC)[reply]

So corrected. Thanks for catching my mistake. --Jayron 32 16:22, 27 October 2022 (UTC)[reply]

Which makes the Imperial gallon a nice round 10 lbs. Alansplodge (talk) 21:28, 27 October 2022 (UTC)[reply]

Well that's exactly what I was taught in first form at prep-school over half a century ago! Martin of Sheffield (talk) 22:02, 27 October 2022 (UTC)[reply]

I suspect that the answer must be that it was a medieval approximation of the Roman Libra, but what the Romans were thinking of, I cannot tell. Alansplodge (talk) 21:57, 27 October 2022 (UTC)[reply]

Back to the OP's question: This discussion at StackExchange is elucidating. The consensus seems to be "¯\_(ツ)_/¯". The pound is originally based on the roman "libra pondo" where libra translates as "pound" and pondo as "by weight". So etymologically, so the English word is based on the roman term for "weight" generically, but the measurement itself is based on a specific roman weight, the libra. The libra itself was based on an earlier Greek unit of measurement (Romans loved copying the Greeks), the "mina", which is a unit of measurement so old it goes back to Ancient Mesopotamia, and the earliest known written records, where its origin is obscure. So basically, no one has any idea what the original pound was intended to be modeled after, because each civilization has basically borrowed the concept from an earlier civilization where it was already established, and when we follow the chain back, it's too long ago to have enough records to figure it out. The actual exact measure of a pound/libra/mina/whatever varied considerably from locale to locale, but usually always meant something in the pound order of magnitude. --Jayron 32 11:09, 28 October 2022 (UTC)[reply]
The Ancient Greek μνᾶ (mnâ), on which the Roman mina was based, was divided in 100 drachmas. There was also a unit called λίτρα (lī́trā) in Ancient Greek, which was divided in 12, a twelfth part being called an οὐγγία (oungiá), clearly borrowed from Latin uncia. The Roman mina copied the Greek mna, whereas the Greek litra was a copy of the Roman libra. All these terms for units are conventionally translated as "pound", but it is not clear how they related, although Galen writes, Μνᾶ δέ ἐστι λίτρα καὶ τρίτον λίτρας μέρος – There is also the mna, a litra plus a third part of a litra.^[1] --Lambiam 07:42, 29 October 2022 (UTC)[reply]
On the translation of "μνᾶ"/"mina", see a multi-translation view of Luke 19:13, part of Christ's "parable of the minas" in the Bible. A few older translations use "pound", and a few paraphrases just give something different (e.g. "some money"), but otherwise virtually everything just renders "μνᾶ" as "mina". 175.39.61.121 (talk) 19:01, 29 October 2022 (UTC)[reply]

Ah, the ancient art of weights and measures, guaranteed to do your head in. I'm afraid that none of our articles begin to do justice to the complexity of the subject. In English/British terms, there were historically several pounds of differing weights: the Tower pound, for weighing money, usually silver; the Troy pound, also for weighing precious metals; the Pound (mass) Merchant's and London pounds for goods; and the wool or Avoirdupois pound. The Troy pound was the Imperial pound of Britain between 1826 and 1855, although the prototype was destroyed in the House of Commons fire in 1836. See Weights and Measures Acts (UK) and Troy pound weight

The general underlying basis of all pounds is the ounce, of which there are three which concern us: the ancient Roman uncia of around 438 grains(gr); the old standard ounce of 450 grains, in use from Anglo-Saxon times at least; and the Troy ounce of 480 gr, also found in the marc Tournois. In many parts of N. Europe, the silver Cologne mark was the standard weight, virtually unchanging over many centuries. The 450 gr Cologne ounce made its way into various weights:

8 ounces of 450 gr = 1 Cologne silver Mark (3600 gr)
12 ounces = 1 Tower pound (5400 gr) = 15/16 Troy pound (for money), 2/3 Cologne pfund
15 ounces = 1 Merchant's pound (6750 gr) = 15/16 London pound
16 ounces = 1 London pound (7200 gr) = 1 Cologne pfund = 2 Cologne marks

——

12 Troy ounces of 480 gr = 1 Troy pound = 5760 grains
12 uncia of 438 gr = 1 ancient Roman libra
16 Avdp. ounces of 437.5 gr = 1 Avoirdupois pound = 7000 grains

Here are some books I have found interesting, although none are particularly recent:

British weights and measures as described in the laws of England from Anglo-Saxon times (Sir Charles Moore Watson)
Second report of the Commissioners...to consider the subjects of Weights and Measures (1820, shows the vast confusing multiplicity of W&M in Britain at the start of the 19th century)
The ancient cubit and our weights and measures (Sir Charles Warren)
The early weights and measures of mankind (Warren again, updating The Ancient Cubit)
The measures, weights, and moneys of all nations (Woolhouse)
Arbuthnot's Tables of ancient coins etc.
A discourse of the Roman foot, and Denarius (John Greaves, 1647)
The Origin and Antiquity of Our English Weights and Measures Discover'd (1745, probably not by Greaves.) Happy reading and best of luck. MinorProphet (talk) 15:14, 2 November 2022 (UTC)[reply]

"Gender-affirming care" for minors in Sweden, Finland, and the United Kingdom?

Last time when I asked about this topic, all attempts to answer my specific question utterly failed. However, this result was well within my expectations since when someone else asked that very same question before me somewhere else, no answer was forthcoming either. Not to worry, the question this time is nowhere near as difficult as the last one. What is the current official status of the treatment for gender dysphoria/incongruence for minors in Sweden, Finland, and the United Kingdom especially puberty blockers, cross-sex hormone therapy, and gender surgeries, aka what many Americans call "life-saving gender-affirming care" in the United States? Please try your best to give a straight answer and if there is any other European countries with the same policies as those three countries, please be sure to name it. StellarHalo (talk) 13:04, 27 October 2022 (UTC)[reply]

According to our article, in the UK, "The minimum age for sex reassignment surgery varies from 16 in Scotland to 18 in Wales." Is that what you mean by "official status"? Our article has a few other nations listed, but not Sweden or Finland, AFAICT. Matt Deres (talk) 16:03, 27 October 2022 (UTC)[reply]

This page seems to have all of the information you seek. The main page has a map, and there's a link to a document with much more details. --Jayron 32 16:10, 27 October 2022 (UTC)[reply]

In the UK the prescription of puberty blockers to under-16s has recently (September 2021) been the subject of litigation in the Supreme Court; our article on the case is Bell v Tavistock. Alansplodge (talk) 22:05, 27 October 2022 (UTC)[reply]

This is the Swedish National Board of Health and Welfare's page on care of children and adolescents with gender dysphoria. There's an English summary and Google Translate will help you with the rest. Sjö (talk) 06:04, 1 November 2022 (UTC)[reply]