Talk:Pound (mass)

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1 Move to Pound (mass)
- 1.1 Result
2 Metric pound
3 Other pounds
4 POV problems
5 Gram-force
6 "Dimensionless" constant can't have dimensions
7 Requested move
8 Pound (mass) should be Pound (weight)
9 Pound mass vs weight.
10 Pound (unit of mass) and other content
11 Pound (weight) redirect
12 Proposed rearrangement
13 Where does lb come from?

[edit] Move to Pound (mass)

I moved this article to Pound (mass) because.. it talks about mass, not weight. Weight is the same as force, and it is discussed in the Pound-force page. This page should eventually redirect to the Pound-force page, but I don't want to mess up all the pages linking here. Bots anyone? Fresheneesz 01:33, 5 December 2005 (UTC)

Ok.. that was reverted. I guess I need supporters. This page is mistitled, anyone want to tell me otherwise? Fresheneesz 05:10, 6 December 2005 (UTC)

Support because this is indeed about the mass unit and it is important to keep the distinction. Of course it was correct procedure to revert the cut and paste move, but the proper move should be done. Stefán Ingi 00:14, 8 December 2005 (UTC)

Support, but not because it doesn't talk about weight. It does, but weight and mass are both ambiguous words with more than one meaning, but the ambiguities in the word weight cause more confusion than the ambiguities in the word mass in this context. One problem here is that "pound-weight" and "lb.wt." and the like are old early 20th century terminology for what is now more commonly called the pound-force, which has its own article. Pounds-force were never well-defined before the 20th century, though they had been used in low-precision measurements for a couple of centuries before then. The pounds in this article are units of weight, and have been quite properly called that throughout history—and they were never called units of mass before the last 300 years, because while weight had that meaning long before then, mass did not. Gene Nygaard 16:28, 10 December 2005 (UTC)

Note that in any case, somebody still needs to fix the approximately 400 links to the disambiguation page now at Pound after User:Chaosfeary butchered everything up in his moves. Only a minority of what was originally over 600 of them have been fixed so far. Gene Nygaard 16:45, 10 December 2005 (UTC)

OPPOSE, article should be at pound (unit) with both pound (mass) and pound (weight) redirecting to it. I was taught in school that a pound is a unit of force, not mass. 132.205.45.148 22:10, 12 December 2005 (UTC)

Comment. So, you were taught badly. You are hardly alone. But leaving it as it is, with the article about the units of mass under pound (weight), isn't going to help you or anyone else. The problem is that the pound-force is a unit (and one sometimes used for things called weight with a different meaning, as well as other kinds of force never called weight such as the thrust of a jet engine), just as the pound at this article is, and so are the units of currency. So using "unit" is even more unnecessarily ambiguous, applying not just to several different units but to different quantities as well. We already have a pound disambiguation page which can lead you to either these units of mass or to the force unit, as well as the units of currency and other meanings. Gene Nygaard 23:56, 12 December 2005 (UTC)

Oppose You were actually the one taught badly from the wikipedia article weight In the physical sciences, weight is the downward force exerted on matter as a result of gravity. An object's weight is equal to its mass multiplied by the magnitude of the gravitational field. That is to say that in terms of actual definition any unit of weight is a force, if you went to the moon your mass would be unchanged but your weight would be less. The should be moved back, or pointed somewhere and the explination that the title with the word weight in it is not technically correct. The redirect it probbly ok but I think the suggestion below redirecting to Pound (unit) and explainning the complications. The way this redirect is, it implies that weight is equvilent to mass which is not at all true. Dalf | Talk 04:02, 24 January 2006 (UTC)

Clearly support. ナイトスタリオン ✉ 09:23, 20 December 2005 (UTC)

[edit] Result

Moved. WhiteNight ^{T | @ | C} 22:49, 28 December 2005 (UTC)

Somebody still needs to clean up after Chaosfeary and that mess of links to the disambiguation page at Pound. Gene Nygaard 02:00, 29 December 2005 (UTC)

[edit] Metric pound

It might be worth mentioning in this article that in France that I know of (and possibly other countries as well that use the metric system, although I only know of the French example), a "pound" is frequently used to describe 500 grams (or half a kilogram). (In France, one refers to a "livre" in this context).

Its not really a metric pound if its not part of the metric system... it probably has similar origins (livre = libre = lb), but its definately not the same as a pound. Fresheneesz 01:35, 5 December 2005 (UTC)

[edit] Other pounds

More info:

Pounds that I know of:

avoirdupois pound = 7000 grains (16 oz of 437.5 grains)
troy pound = 5760 grains (12 oz of 480 grains)
Tower pound = 5400 grains (12 oz of 450 grains, I think)
mercantile pound = 7200 grains (15 oz of 480 grains (same as troy))

The last three are all obsolete (nobody uses troy pounds today, though troy ounces are still in use for gold, etc.)

Also, the section "Troy pound" says that a pennyweight is the weight of a penny in Henry II's time, and a fraction of a troy ounce, but in Henry II's time it would have been a Tower ounce, which is somewhat lighter -- the Tower pound was only replaced with the troy pound for monetary weights by Henry VIII (or maybe it was Henry VII; rather later than Henry II, anyway)

I read the linked article, and I've still got some problems with defining pound as mass. It seems like the governments that define a pound as mass do so just because they don't care to differentiate between the mass of an object and the force that gravity exerts on the mass. Maybe they'll come round once we get moon colonies started :-) Governments can make laws saying that dogs are actually cats, but my physics book says,

In the British system, the unit of force is the pound (or pound-force) and the unit of mass is the slug. The unit of acceleration is one foor per second squared, so

1 pound = 4.448221615260 newtons.

Webster's dictionary also specifies the aviordupois pound as a weight. -- Merphant

That it is called weight does not in any way imply that it is "not mass."

Those government officials not only care about the difference--but they are also a whole lot smarter than you are, and they use the definition appropriate for the circumstances.

Why in the world do you suppose governments bother to define a pound in the first place? When we buy and sell goods by "weight," we certainly should not measure some quantity which varies with the strength of the local gravitational field. We do not do so. We have never done so. That pound defined as 0.45359237 kg is the pound legal for commerce in the United States. Just as it should be--until they finally come to their senses and outlaw it, leaving only kilograms and their multiples and submultiples as the legal units for this purpose.

When that net weight appears on the label of some U.S. product, the pounds and ounces are, of course, every bit as much units of mass as the grams and kilograms which appear right alongside them. No manufacturer measures two different quantities for this purpose, measuring force for the figure in pounds and mass for the figure in kilograms. No manufacturer puts one "weight" on their products for sale in Barrow, Alaska, and a different "weight" on the same product when it is sold in Honolulu, Hawaii. Nor should they do so.

Note that nowhere in the world are newtons legal units for the sale of goods. Nowhere in the world are kilograms force legal units for the sale of goods. Nowhere in the world are pounds force legal units for the sale of goods.

This is the quite proper and legitimate original meaning of the word "weight," which entered Old English over 1000 years ago meaning the quantity measured with a balance. That quantity is mass, not force. It was used as a measure of how much stuff they had, for the purpose of trade. We still use the very same word, with the very same meaning, for the very same purposes today.

Gene Nygaard 16:14, 6 Dec 2004 (UTC)

There's lots of authoritative citations about the pound always being a mass at:

These link to official legislation, history, and authoritative standards bureaus. The pound is a mass, and always has been (well, for over a century, at least.)

http://futureboy.homeip.net/frinkdocs/faq.html#pound

I should note that my comment for the checkin to the article that read "It's not mass... if you think it is, provide references to any standards body that's defined it as a mass since 1893." were totally wrong. This should read, "It's not force/weight... if you think it is, provide references to any standards body that's defined it as anything but a mass since 1893."

If pounds are mass, then why does every (American) science text book says something like "You would weigh 42 pounds on Mars." It may not be what the standards body uses, but it is what people think. I also remember my physics professor saying that pound is a unit of weight. Now he may not be in concordance with the standards body, but it is common usage, which is what wikipedia should present?McKay 20:03, 24 Aug 2004 (UTC)

lbm should be mentioned, even if its use is not recommendable. It is used, see e.g. http://www.glossary.oilfield.slb.com/Display.cfm?Term=lbm%2Fbbl. -Patrick

Indeed. In that case, we have to mention it; and also say that its use is not recommendable. Likewise, for example, writing "gm" as an abbreviation for gram. -- Tarquin 14:37 Dec 23, 2002 (UTC)

The pound is traditionally a unit of force and weight and is still often used in that sense. The unit was defined before people knew that mass and weight were two differnt things. For anyone who thinks a pound is always a mass, please explain the derived unit of torque, the foot-pound, which is a product of a force and a length. The word pound remains quite ambiguous although, today, it is generally (but, by no means, always) used to mean a mass. Bluelion 19:26 Mar 23, 2003 (UTC)

Pound is for mass, which is also the historic interpretation and definition (see historical weights and measures). Pound (for mass) is abbreviated lb. Pound-force is abbreviated lbf. And there is NO other abbrevitaion for a netric gram but g. Gram is a unit of mass only, always has been. (There used to be a pond unit for gram-force, but this is now totally obsolete). EOD. -- Egil 07:55 Mar 26, 2003 (UTC)

No, pound is for weight historically, and AFAIK still is. Long ago, people weren't aware that mass and weight were different, of course.

I was unaware that anyone thought of it as a mass measure. I edited the page to fix that, but undid the edit after reading the rest of the page and this discussion...someone should sort it out, though. -- User:Tacitus Prime

You could not be more wrong. Pound (lb) historically is both a force and a mass; it always has been and it still is. Drawbar pull of a railroad locomotive, expressed in pounds, is not a mass, for example. There are many others. I notice that the historical weights and measures article you referenced has a lot of empty spaces - needs to be filled in. Bluelion 12:53 Mar 30, 2003 (UTC)

This is historically totally wrong: If anything, pound was at the outset a unit of mass AND a monetary unit. The pound for force must have crept in gradually in the 1700s or thereabouts, but in modern usage it has again become important to separate the two. In modern correct usage (to the degree use of the "pound" unit can be considered "modern") pound as a force is pound-force or lbf. The online EB defines "pound" as unit of avoirdupois weight, equal to 16 ounces, 7,000 grains, or 0.4536 kilograms, and of troy and apothecaries' weight, equal to 12 ounces, 5,760 grains, or 0.37 kg. The Roman ancestor of the modern pound, the libra, is the source of the abbreviation lb. In early England several derivations of the libra vied for general acceptance. -- Egil 05:14 Mar 31, 2003 (UTC)

"If anything, pound was at the outset a unit of mass AND a monetary unit."

Funny, I would have thought it was a weight and a monetary unit. To say it was a mass is revisionist history. If the question is what is 'proper' today, then I have no problem with saying that pound means mass. But saying that, in common usage, that is all it means is a crock. And saying that that is what it has meant historically is also a crock. Before about the middle of the 20th century, I'm quite sure it meant both a force and a mass (yes, I'm that old). And, at that time, I'd bet the prevailing opinion was that it was a force. In recent years there's been quite a campaign by the protectors of all that is good and Holy to get it to mean a mass but, historically, it was both a mass and a force. Unless all the books I have that use the abbreviation lb to represent a force don't exist, and unless the education I got in engine school didn't happen, and unless psi represents a mass per unit area, then the word pound is ambiguous. It means either lbm. or lbf.; we can't be sure unless we know the context. It's a lot like the word billion in that respect. Bluelion 03:19 Apr 1, 2003 (UTC)

FWIW, I remember physics exam questions from school (early '80s) dealing with converting kilograms to pounds on the moon, etc., i.e., taking pounds to be weight, not mass (that was an American school). Also, my old physics 101 text (Physics, Paul Tipler, 1982) defines a pound as a weight/force. Seems to me, to people who really care about the difference, it's a weight; those who say it's a mass probably don't know the difference :)

---

--Use of Imperial Pound--

The definition of the imperial pound as "obsolete" needs clarification as the unit is still a de facto, if not official, measurment used more frequently than metric in many areas in the United Kingdom. An example is that of measuring the weight of a person in Stones (units of 14ibs) and Pounds and virtually all medical forms completed by patients recognise this practise by allowing the use of either metric or imperial. It is not simply an allowance for older people and feet and inches are used equally for human measurment in everyday situations. Also in boxing arenas the weight of the fighter would never be anounced to the crowd in Kg It would either be in Stones/pounds, or Stones/pounds and Pounds alone where there is likely to be a transatlantic audience for a British boxer.

[edit] POV problems

This article had some serious POV problesm, and I think it mostly fixed it. I know it's not perfect so feel free to make stuff look right.

if anyone has some serious griefs with my expressing pounds as weight as the de facto standard, lets discuss itMcKay 08:33, 13 Nov 2004 (UTC)

Hi McKay -- Could you explain more about what you mean? I'm actually fairly happy with the article as it stands. I'm not sure it's accurate to say that layment consider it a unit of weight; laymen actually don't understand the distinction between mass and weight. --Bcrowell 01:54, 15 Nov 2004 (UTC)

How much do you weigh? It's a completely serious question. I doubt that you would express your answer in newtons or say that your mass is 42 kilos. While some (women) won't want to tell you, or will lie. Any answer you get (in the United States), scientist or not, will be expressed in pounds. That's basically it. The Pound as a unit of weight is the de facto standard.

You also make the claim that the layman doesn't know the difference between mass and weight, and while there are a whole lot of people who don't, I would say that most "laymen" do. They teach this stuff in elementary school science classes. My little sister of 10 knows the difference, but she doesn't think that pounds are a unit of mass. When I was in elementary school science classes, I did a report on Saturn. At that time I could tell you how much you weighed on Saturn. (I forget the multiplier now, it might be in the Saturn article. I don't care to check. Mars is 0.6, Moon is 1/6? ) Such a distinction requires knowledge of the difference, or at the very least, a knowledge of the proper understanding of the weight concept (even if the mass concept is unknown). McKay 03:42, 15 Nov 2004 (UTC)

Hmm...I teach college physics, and I wish all my students understood this distinction, coming into my class, from elementary school science. My experience is that almost none of them do. If you ask someone in the U.S. what his weight is, he'll answer in pounds. If you ask someone elsewhere in the world, he'll answer in kilograms. Since the kilogram is undeniably a unit of mass, not weight, I think that demonstrates that the typical person does not understand that there is even a distinction between the two quantities. As a physicist, I think the current state of the article does a fairly good job of discussing how these terms are understood by physicists. What I think would help immensely would be if we could get some contributions from someone who is an engineer in the U.S., and does calculations using the fps system; they are basically the last people in the world who actually calculate things using Newton's laws in the fps system. The NBS article is, to my mind, almost irrelevant, because I know it doesn't represent a clear consensus among physicists, and I suspect it doesn't represent a consensus among U.S. engineers either. A government proclamation can't change the meaning of a word unless it actually matches the way people use the word. I'm still a little unclear about what you meant by POV issues; to me this does not seem to be an issue relating to POV/NPOV, but maybe I'm misunderstanding you. --Bcrowell 19:34, 15 Nov 2004 (UTC)

Just as pressure and stress have different meanings in physics class from what they mean in a psychology class, weight has different meanings in different fields. Sure, in physics and engineering weight means "gravitational force", but in commerce and law it means "mass". When something is sold by weight or by the pound, it's mass and the pound-mass that are being used: it's the amount of the substance that's of interest, not how hard it presses against the ground. Likewise when someone measures body weight to assess health or attractiveness, it's how much matter is in the body that is concerned: being overweight would be just as unhealthy in a low-gravity environment. Body weight is measured in pounds-mass. In fact I can't think a "layman" use of pounds that are pounds-force (except if you consider torque in foot pounds and pressure in pounds per square inch as "layman" uses). It would end a lot of ambiguity if everybody quit using the word weight completely, replacing with "gravitational force" or "mass" as appropriate, but that's not likely to happen. Just as a government can't change the meaning of a word, neither can authors of physics textbooks change the meaning of word outside their field. Indefatigable 23:06, 15 Nov 2004 (UTC)

You see the facts pretty well, Bcrowell--you just appear to have some great difficulty understanding what you know. Yes, kilograms are indeed used for body weight throughout the world, including many hospitals in the United States. And they are indeed the proper SI units for this purpose, as NIST tells us in the external reference on the article page, at [1]

Thus the SI unit of the quantity weight used in this sense is the kilogram (kg) and the verb "to weigh" means "to determine the mass of" or "to have a mass of".

Examples: the child's weight is 23 kg

the briefcase weighs 6 kg

Net wt. 227 g

It is your failure to understand that the pounds also used for this purpose in the United States, when used in either the medical sciences or in sports--the primary reasons we weigh ourselves--are the pounds legally defined as units of mass equal to 0.45359237 kg exactly.

Naturally, if you have been miseducated (as your students likely have been), told that pounds are not units of mass, you have to resort to such a faulty explanation. You imagine a discordance between the use of pounds for weight and the use of kilograms for weight which does not exist. Your major problem is a failure to understand the simple fact that "weight" is an ambiguous word, and it is compounded by your failure to understand the simple fact that pounds are and always have been primarily units of mass, not force. (The pound force is such a recent bastardization that it is uniquely identified by that name. There is no troy pound force, for example. There is no metric pound force.)

The Body Mass Index is also properly named. It is weight in kilograms divided by the square of height in meters. Or you often see it expressed in terms of weight in pounds and height in inches, with a conversion factor added. That conversion factor is always a constant (because of rounding, different people might use different values--but each author only uses one value). The exact number used in the Wikipedia article at the time I write this is 703.07, which is clearly too many digits to be used for pounds force without specifying a location--but one correct to that many digits for the pounds we do use. Nobody ever uses a variable dependent upon latitude and altitude in this context, which it would have to be if your mistaken belief that the pounds used for this purpose in the medical sciences are pounds force were true.

Note also that hospitals which have scales which can measure in either pounds or kilograms (it is often the same scale) do not use different methods to calibrate them for the measurement in pounds from the methods they use to calibrate them for the measurement in kilograms. It is a constant conversion factor between the two, whether it is accomplished by flipping the bar on a balance beam to get a different set of detents for the movable weights, or a constant conversion factor programmed into a microchip.

Note that the pennyweight, like the troy ounce or troy pound, is always a unit of mass. Similarly, the hundredweight (even for those who think hundred is written in digits as "112") and the stone (1/8 of a long hundredweight, still used for body weight in the U.K.), unlike the pounds on which they are based, have not spawned units of force of the same name.

Here's American Society for Testing and Materials, Standard for Metric Practice, E 380-79, ASTM 1979: "3.4.1.2 Considerable confusion exists in the use of the term weight as a quantity to mean either force or mass. In commercial and everyday use, the term weight nearly always means mass; thus, when one speaks of a person's weight, the quantity referred to is mass. . . . When the term is used, it is important to know whether mass or force is intended and to use SI units properly as described in 3.4.1.1, by using kilograms for mass or newtons for force."

BTW, it is also not true that kilograms are "undeniably units of mass, not weight" because the kilogram is usually a unit of mass when it is a unit of weight. But furthermore, changing your last word to "force" wouldn't matter either. The kilogram-force was a quite legitimate unit (also known by another name even, the "kilopond") before the introduction of SI in 1960. There were even coherent systems of units devised with the kilogram force as a base unit of force, with the derived unit of mass the kgf s^2/m, known by several different names such as hyl, TME from a German acronym, metric slug, or mug, because this wonderful invention recurred to several different people bound and determined to show that those using metric units can be every bit as silly as those using English units. We still see far too many vestiges of the use of these obsolete kilograms force--but rarely for anything called "weight" in anybody's book, in any of the various different meanings of this ambiguous word. We see them used for thrust of jet and rocket engines, for tension of bicycle spokes even in the U.S.A., for pressure gauges in "kg/cm²", for torque wrenches in "meter-kilograms", etc. Nobody calls those forces weight. OTOH, the kilograms that are used for body weight of humans, or of other animals as well in fields such as zoology and veterinary medicine, and the kilograms that are used for "net weight" of anything are always units of mass, not force. ("Net weight" is not a physics term.)

The worst of it, however, Bcrowell, is that I suspect that you are not merely a physics teacher, but also a textbook author--of a textbook distributed primarily on the Internet, no less--who has spread his misconceptions in this field far beyond his own classroom.

Gene Nygaard 17:26, 6 Dec 2004 (UTC)

I agree with Gene Nygaard here. The entire section added about force, weight, and mass confuses the issue, and is very poorly written. And of course the pound is only a unit of mass, and has been clearly defined as only a mass by all standards bodies and legislative definitions in all countries for well over a century. I'd recommend that the entire force, weight, and mass section be removed. It's meandering, wrong, and only comes from one person's very confused misconceptions.

In addition, I bristle at any article that says "but physicists/laymen/(insert other confused group) take it to mean something different" and then explain only their own confused, baseless misunderstandings. All such parts should be removed. People don't come to Wikipedia to find out about what some clueless people believe--they come to find out what's actually right. The standards bodies (and even legislatures) that created these definitions well over a century ago clearly understood the difference between mass and weight, and differentiated them unambiguously. Too bad those who teach our kids don't. --Eliasen 08:22, 9 Jan 2005 (UTC)

Sounds fine with me. Elf | Talk 18:48, 9 Jan 2005 (UTC)

Eliasen, you know darned well that pounds are also units of force. Why are you trying to bury your head in the sand?

Most of the information on the pound-force and its definitions and use belongs in the article of that name, but it needs to be mentioned here as well.

It is very important to retain discussions involving the ambiguous word weight. There are far too many people who have gotten the mistaken notion that because a pound is a unit of weight it cannot be a unit of mass (a notion totally contrary to the fact that of all the pounds used throughout history, only one was also used as a unit of force to any significant extent). OTOH, we also have the confused people of Eliasen's class, insisting the opposite: that pounds are not units of force (even though from what I have seem, he or she appears not to understand the ambiguous nature of the word weight so the previously mentioned confusion would seem more probable).

There are also far too many confused science professors in our colleges and universities, and high school teachers and the authors of some of the textbooks they use, filling the heads of students with the nonsense idea that they should measure "their weight" in newtons rather than kilograms or pounds. (And most everybody gets somewhat confused about this—and quite understandably so—failing to understand that the pounds used for this purpose in medicine and sports are units of mass, and that the pounds used for this purpose in many science textbooks, science museum exhibits, and other discussions of "your weight on other planets" are pounds-force.)

There are far too many professors and textbook authors who imagine themselves to be cheesemongers or purveyors of sugar, potatoes, bananas, or whatever, who do not understand that the kilograms used for that purpose—and, most important to this article, the pounds and ounces which appear right alongside them on labels in the United States—are units of mass, not units of force. I guess they must think that talking about the sale of cheese in a physics class can somehow magically change the rules—and they are the proper rules—governing its sale. (Of those who think the pounds are units of force, some think the kilograms are units of force as well, and others imagine some weird statement of measurements of two different quantities on the labels.) Gene Nygaard 13:40, 11 Jan 2005 (UTC)

Let me be clear. The pound is a unit of mass. The pound-force is a unit of force, but that is not the pound. I have never said otherwise. Gene, do you have references by any standards body from any country in the past century that says that the pound is a force? If so, please produce it, otherwise, we should drop the whole force sections, which are in error. I don't want a confused colloquial usage, nor an industry shorthand, but an official standard by a national or international standards body. Say, since 1878 in the UK or 1893 in the U.S.? If so, we can maybe re-open this discussion, but it's been quite clear for a long, long time to all standards bodies (and even legal bodies, except for a minor confusion in Canada's legislative heading of the section of law that defines the pound.) Again, I have placed further references for a wide variety of countries and standards bodies [here]. Do you dispute any of these countries' definitions?

Gene, why do you say that people shouldn't measure their weight in newtons? That is, in fact, totally appropriate. Do you not agree that a newton is a force and that is indeed what is measured by almost all scales? If they're indicating their mass, it should be in kilograms or pounds. Weight is, obviously, not invariant under different accelerational frames, but newtons (or pounds-force) are quite appropriate to measure this varying quantity. I don't know where the confusion lies in your understanding.

I agree that discussion of the pound-force should be in this article. In fact, I believe I put discussion of the pound-force in originally and linked to the pound-force article. It was simple, concise, and sufficient to show the difference. I will reiterate my opinion that any encyclopedia should focus unambiguously on correct usage, not confuse the issue with enumerating the endless permutations of incorrect colloquial usage. That isn't what an article on the pound should be about.

I do believe that if people are confused about the difference between force/weight and mass, then that should be an entirely separate article, and not crammed into the article about the pound, otherwise it will be duplicated among all articles about mass or weight. This article needs cleanup badly. --Eliasen 08:29, 17 Jan 2005 (UTC)

I'll number my comments to correspond to your paragraphs 1-4.

1. Even if standards bodies had defined a "pound-force" that would not mean that pounds are not units of force. Any time you define something as a noun-adjective combination, it is logical and reasonable to expect that the adjective will sometimes be dropped.

However, since standards bodies haven't bothered to define pounds-force, even that is irrelevant. The existence of the pound as a unit of force, whether it is called just a pound, or by the old name "pound-weight" (which at least one old engineering textbook used to mean the geepound or slug, a unit of mass, instead), or the "pound-force" is determined by usage, not by standards bodies who have not acted. Various standards bodies have, of course, recognized the existence of pounds force. See, for example, the footnote 24 in NIST's appendix of conversion factors in SP811, giving a conditional definition of the pound-force. [2]

The main reason I brought that point up was to make sure that those reading this Talk page know what you know. You had written it like you were a dummy who didn't know pounds-force exist; whereas you merely intended to write it like a dummy who didn't know that they are called "pounds."

2. Show us some examples of the use of pounds-force for body weight (keeping in mind that you are the one claiming that pounds are not units of force if they are not identified as such). Better yet, show us all the examples you can find, from all around the world, of people using newtons rather than kilograms for body weight of humans, or of other animals as well in the veterinary or zoological sciences, for that matter.

"[M]easured on almost all scales?" So what happens when you get serious about your weight, and go to the doctor's office or the gym, and weigh yourself on one of those platform-type beam balances? Isn't that a better indication of what you want to measure, than a substitute considered acceptable in many homes because it is cheaply made? Furthermore, those cheap bathroom scales didn't even exist until 1937, well within the lifetime of many people living today. Those spring scales are no more accurate in measuring force than they are in measuring the mass at the location in which they are used.

How about those old scales that used to be seen in public places, where you could put in a penny and get your fortune told, as well as your Honest Weight: No Springs?

"[M]easured on almost all scales?" In a hospital, where they are concerned about not having discrepancies between the scales in different departments, or when someone is transferred to a different hospital, how are those scales calibrated?

Here are some of your "standards bodies" on this point. American Society for Testing and Materials, Standard for Metric Practice, E 380-79, ASTM 1979:

3.4.1.2 Considerable confusion exists in the use of the term weight as a quantity to mean either force or mass. In commercial and everyday use, the term weight nearly always means mass; thus, when one speaks of a person's weight, the quantity referred to is mass.

NIST Guide for the Use of the International System of Units (SI), section 8.3

Thus the SI unit of the quantity weight used in this sense is the kilogram (kg) and the verb "to weigh" means "to determine the mass of" or "to have a mass of."

Examples: the child's weight is 23 kg

3. You don't even have any clear-cut, universal rules for the use of pounds force (or, for that matter, of English units in general), and not much from any standards organizations in the way of any guidance in their use, so even though I disagree with your philosophy here, it is irrelevant.

4. The confusion most often seen in this regard, the confusion specifically mentioned by many standards organizations, is the confusion you seem to share (based on your "force/weight" and "mass" dichotomy, as well as your discussion about teachers in an earlier comment) with many (other?) science teachers—the failure to understand the simple fact that weight is an ambiguous word, one with several different meanings. Just remember this to help keep it straight in your mind: in the troy system of weights there are no troy-ounces-force and no troy-pounds-force.

You've seen on this talk page, and on edits to the article itself, how this confusion about weight is the root cause of many peoples' beliefs that pounds cannot be units of mass. Even if it is discussed adequately (and relatively permanently, by Wikipedia standards) in another article, a good, strong summary accompanied with a link to that discussion is important in this article.

Gene Nygaard 15:02, 17 Jan 2005 (UTC)

McKay, I hope that little sister runs into better teachers. Soon.

Maybe you could point her to the discussion on this page.

Gene Nygaard 10:43, 8 Dec 2004 (UTC)

...which is a dimensionless constant, defined as 32.17405 lb ft/(lbf s2) and approximately equal to the typical acceleration of gravity on Earth, in ft/s2.

Is the use of the word dimensionless appropriate here?

It could probably be worded better (mea culpa), but it is indeed dimensionless though it is not unitless. See dimensional analysis (a link to that in connection to the quoted statement might be helpful). As that says, a dimension is "the type of unit needed to express it"; for example, feet and meters have the same dimension, something that in this context is usually called "length", often symbolized L. Other dimensions involved here can be called "time" T and "mass" M (other "dimensions" could be chosen, for example force rather than mass, with the same end result). Let's do the dimensional analysis of those units:

unit                   dimension
lb                       M
ft                       L
lbf = 32 lb·ft/s²        M L T^-2
s²                       T²

and then combining them for overall dimensions, lb ft/(lbf s²) = lb ft lbf^-1 s^-2, so the dimensions are:

(M¹)(L¹)(M^-1 L^-1 T⁺²)(T^-2) =

M⁰ L⁰ T⁰ (i.e., dimensionless)

Now do the dimensional analysis of a formula involving this g_c and you will see that the units as they are expressed in the quote above are indeed the correct units. Note the distinction made in the article between this conversion factor used in formulas, something called g_c, and the standard acceleration of gravity, g_n = 32.174 ft/s², which has dimensions of acceleration, or L T^-2. Gene Nygaard 14:16, 27 Jan 2005 (UTC)

You're right, of course. Thank you for the explanation. Having been brought up on SI I'm not used to these conversion numbers. Somehow, it feels a bit less dimensionless than some numbers, though. ;-) Possibly the wording could be improved by changing ...and approximately equal to the typical acceleration... to ...and numerically equal to the typical acceleration.... I was confused by the units on the acceleration and assumed that the units on g_c cancelled to the same.

I added a note about actual use in some applications. I've never seen anyone in my chosen field of study (structural engineering) use pound as a unit of mass. Because of this, a lot of textbooks and references (including the AISC and ACI building codes) use "lb" by itself as a unit of force and slugs as mass, since carrying around g_c is an invitation to disaster. I think that it's useful to tell people that regardless of what standards bodies say lb "should" be, they will run into situations where convention is almost exclusively in the other direction. As an aside, I'd like to know what fields use lb as a unit of mass. I'd been under the impression that civil and mechanical engineering are just about the only scientific fields left that use the imperial system in places where the distinction matters (having to convert between weight and mass). I know that civils usually use lb for force, and have heard anecdotally that mechanical engineers generally do the same.

I don't know if the note should be moved to another place, maybe under the discussion of force vs. mass, but I felt that since it's primarily discussing the labeling issue, I put it where it is.

J. W. Prusi, 03 OCT 2005

[edit] Gram-force

RE: Egil 07:55 Mar 26, 2003 (UTC)

Yes, a metric gram is abbreviated to g; this refers to mass. And, there is no force equivalent because one gram of force is a thousanth of a newton. (N= kg*m/s²) Since this is clear and obvious to even people with only a high-school level of scientific knowledge (most people, although perhaps not most wikipedians) and since the majority of the world now use the metric system, why not stick to it instead of getting into petty quarrels over the history of a redundant unit? --220.238.255.204 04:54, 2 August 2005 (UTC)

No, a gram-force is 9.80665 millinewtons, about a hundredth of a newton, not a "thousandth of a newton" or 1 mN. Guess you aren't among those people with a "high-school level of scientific knowledge", right? Gene Nygaard 05:46, 2 August 2005 (UTC)

[edit] "Dimensionless" constant can't have dimensions

My correction removing the word "dimensionless" was reverted. I've re-read the talk page on this, and I can see how the word can be defended, but the sentence in is unclear this way, as it still states the number has units. I've made what I hope is a clarifying change.--Jeepien 19:45:27, 2005-08-25 (UTC)

[edit] Requested move

Talk:Pound--Pound→Pound (disambiguation)
Pound (weight)→Pound

This is a three-way request, please discuss at Talk:Pound. Gene Nygaard 16:30, 17 November 2005 (UTC)

[edit] Pound (mass) should be Pound (weight)

I dunno about you guys, but every physical science class I've ever sat through has made the distinction that the pound is a unit of weight and the kilogram is a unit of mass. It's always been very clear-cut for me. If I'm on Earth, I weigh 135 lbs. If I'm on the Moon, I'll weigh 22.4 lbs. If I'm on Earth or the Moon, I'll be 61.4 kg.

So why is this article titled Pound (mass)? It's not a unit of mass, it's a unit of weight. I have never heard differently until now, and I've sat through a lot of science classes... --Lantoka 05:49, 20 April 2006 (UTC)

Please see discussion above, and the section "Force, weight, and mass" in the article. Standards organizations today treat the pound as mass. Engineers and the general public often use the pound as a force (Google the phrase "pounds of thrust", for example). The general public generally does not distinguish between measurements of weight (using a spring scale) and mass (using a balance). High school physics teachers (and textbooks) who use the pound at all (as opposed to the metric system) seem to fall into two camps: those who use the pound as a unit of mass and the poundal or pound-force (lbf) as the unit of force; and those who use the pound as a unit of force and the slug as a unit of mass. Scientists and university physics classes don't really use the pound, so don't have an opinion. Personally, I think it's a bad idea to use the pound as a unit of force, but... by the principle of NPOV, WP should discuss all these uses, making clear which is appropriate when. So the article should probably be "Pound (unit)" and introduce the mass/force issue closer to the top. --Macrakis 14:02, 20 April 2006 (UTC)

The general public maybe doesn't generally distinguish, but the law does, and the usage of manufacturers and government regulators are totally uniform and consistent. The pounds used for "net weight" in selling goods by weight are, and should be, always units of mass, never units of force.

Same goes for human weight, as that is used in the medical sciences and in sports, always units of mass.

The pound-force quite deservedly has its own article. That helps keep the distinction straight; we can link to the correct article. Any mismash which discusses varying units of mass and force in one article would be counter-productive for this usage. Gene Nygaard 18:40, 3 May 2006 (UTC)

I'd support renaming the article to Pound (unit). I can accept that there are other points of view on this issue, but the title of this article just seems a blatant contradiction to me. Pound (unit) should appease everybody and lay the issue to rest once and for all. And it should be done soon, too, since new articles are created every day that link to the pound, and it's gonna be hell to fix all those links... —Lantoka ^{( talk | contrib)} 00:30, 21 April 2006 (UTC)

So, what's your rush? Sure, new articles are created every day. But of all the existing articles which link to either this article ("pound (mass)") or to pound-force, exactly how many can you show us where the link is to the wrong article? Even one? Sure, that's entirely possible. But not 1%, I'll bet. Gene Nygaard 18:45, 3 May 2006 (UTC)

After reading the entire article and talk page, obviously I'm not the first person to have this idea or complaint. This seems like an overly pedantic argument to me. A compromise should be reached so that we can put this issue to rest. What exactly are objections to "Pound (unit)" again? —Lantoka ^{( talk | contrib)} 00:42, 21 April 2006 (UTC)

"Pound (unit)" might work as, but is unnecessary for, renaming of the "Pound" disambiguation page, for the many units of currency as well as several different units of mass and one unit of force. Gene Nygaard 18:28, 3 May 2006 (UTC)

[edit] Pound mass vs weight.

I've been watching this page for a while, partially with disgust. The comment I posted 2 years ago, still doesn't have a response here (Textbooks saying that if you weighed 150 pounds on Earth, you would weigh 55 pounds on mars). I've "fixed" the article to present a NPOV. One that doesn't "favor" the scientists and the standards bodies.

I don't remember why I first came to this page, but I will admit that I have learned quite a bit about this topic since then (including some original research). Also, I have learned a lot about how wikipedia works over the past couple years, so I bring my knowledge to the table.

A comment was made above about laymen not knowing the difference. I have done some 1st class research on this area (blind surveys), and I have found that laymen do know the difference.

Another comment was made above about coming to wikipedia for what is right, not what people think. This is also incorrect. If a (large) group of people think it, it should be represented in Wikipedia. If only what was said here were true, the articles on Relational Database Management System, Relational Model, Relational Database, and virtually every other article with the term "relational" in it would be a lot different, and a lot simpler. Only showing the "techinically correct" side of things is a POV.

All in all, I stand by this edit, and I think that it shows technical correctness, as well as the laymens perspective in the correct light. If you have any further questions, let's work this out.McKay 05:24, 6 August 2006 (UTC)

You raise interesting points. I think the basis of the issue is twofold. First, the pound arose before the difference between weight and mass was understood. And second, that nowadays it is used to mean different things - sometimes as a unit of mass and sometimes as a unit of force.

I too have been told by physics and math professors that the pound is a unit of force, and have even been made to work exercises with "pounds" (units of force) and "pounds-mass", and "slugs" and other odd creatures. I must admit that this now troubles me, since one of the most common real-life usages of the term - in supermarkets - is exclusively as a unit of mass. So as people are being educated, they use pounds as mass, and then are taught pounds as force.

I suspect two possible reasons for this. First, perhaps these professors are familiar with industry practices (please do not laugh) in such areas as aerospace and engine manufacture, where the pound is used generally as a force, unlike most other uses. Or second, and perhaps more likely, is that instructors are keen to deprecate the pound since it is ambiguous, and originated when the difference between weight and mass was not widely understood. And in their zeal to assign every term to its rightful place, they ignore common usage and erroneously say, without reservation, that it is a unit of force.

That is just my speculation, of course. --Yath 15:39, 7 August 2006 (UTC)

Thanks yath, Where were you two years ago, when I tried stating that pounds was a unit of force and all I got was resistance. (of the force variety). Yes yath, I guess I do agree with the article as it's presented, mostly by pushing it elsewhere. So, I think that this means that my work here is done, of to Weight. McKay 06:58, 15 August 2006 (UTC)

On the other side of the "zeal" equation, we have wikipedia editors who will gleefully point out that professors are wrong, because the government defines it as a unit of mass. Of course that is just another example of cherry-picking facts, probably for the satisfaction of showing teachers up. --Yath 07:13, 15 August 2006 (UTC)

[edit] Pound (unit of mass) and other content

I have been bold, and restructured/reformatted the existing content so that it relates only to the topic of the pound as a unit of mass. In the case of the troy pound, I have limited the content to the pound: it seemed to me that other troy units of mass were better dealt with elsewhere. In the case of the distinction between 'mass' and 'weight' (and 'force') it seemed to me that was better dealt with elsewhere, rather than elaborated on in an article about the name of a specific unit of mass. In the case of the elaboration of the use of 'pound' as a unit of force, it seemed to me that it was better dealt with in the article on pound-force. I've put early pointers to these topics in the article. Fibula 16:47, 6 August 2006 (UTC)

I am highly in support of your moving of the irrelevant and misguided content, which did not serve to underline the proper definition of the pound. It needed to be done, as the content removed was only an attempt to reinforce some individuals' personal misinterpretations of the proper definition of the pound. --Eliasen 21:19, 7 August 2006 (UTC)

What I am trying to do is to have the initial part of the article deal with 'today's pound' and the latter part of the article deal with how we got to where we are today (the history and the pounds that have largely or totally fallen by the wayside over history). Fibula 19:56, 8 August 2006 (UTC)

[edit] Pound (weight) redirect

I have changed the Pound (weight) redirect to Pound (mass) from Pound-force. If you look at what links to Pound (weight) almost all the articles are referring to the pound used as a unit of mass (eg amount of stuff) rather than as a unit of force. Some of the articles no doubt are referring to force, but that is the lesser of the two evils. It will take a month of Sundays to go through the articles linking to Pound (weight) individually to make sure they are pointing towards the correct destination. Fibula 16:56, 12 August 2006 (UTC)

So many links are wrong (and need to be corrected anyway) and some are right. The logical redirect is to pound-force, because weight is a special kind of force (not mass). That’s one weak argument for your version of the redirect and one strong argument for mine in my eyes.

The misguiding links are probably to some degree a result of robots applying recent changes in the article title of what is currently pound (mass). They’ll probably change quicker if the result when clicked is unexpected. That would be another argument for a redirect to pound-force. I actually even wouldn’t mind if that article was moved to pound (weight).

I therefore will now revert. Christoph Päper 13:12, 15 August 2006 (UTC)

Actually, weight is a multipurpose term that can mean mass or force due to gravity. But the current arrangement of articles is pretty bad in any case. All we really need is pound (weight), which can describe the meaning of weight (briefly), and the role of the "pound" as a unit of mass or as a unit of force. It could also mention the specific term "pound-force", and voila all the bases are succinctly covered. --Yath 13:59, 15 August 2006 (UTC)

I do not agree, for the reasons set out below under 'Proposed rearrangement' and because I think this should be made User-friendly. In many day-to-day contexts, when people talk about 'weight' they really mean 'amount of stuff' (eg two pounds of cheese) rather than 'gravitational force'. If I were (say) a Frenchman reading an article about a 10-pound cat and I wanted to know what was a 'pound', I would be a little surprised when the (broken) link to 'Pound (weight)' took me to an article about force, when what I expect to discover is what meant by that unit of mass and hope to understand how it equates to the kilograms I use in my day to day lifeFibula 23:41, 17 August 2006 (UTC)

A couple of comments:

Most of the links to pound (weight) are merely remnants of changes made when some misguided soul moved the article now here at "Pound (mass)", which was then at a simple "Pound", to "Pound (weight)", before it was changed to "Pound (mass)". That's one of the reasons why all the links to "pound (weight)" are and should be redirected here. They just haven't been cleaned up yet.
The exact phrasing and word order and punctuation "pound (weight)" is mostly a Wikipedia phenomenon. That reduces the chance of somebody mistakenly using the term which redirects here when pound-force is intended.
Note also that the situation would be different for pound-weight (no parentheses), which arguably should redirect to pound-force. It is now a redlink, and has no articles linking to it. This particular usage was common in many textbooks around the first half of the 20th century. Nonetheless, since I doubt that it is common enough today to warrant it, and also because it might also mean the pound as a unit of mass just as the "pound (weight)" links do, that creating a redirect is desirable. If one is created, I'd say send it to the disambiguation page a "Pound" and let someone come along and figure out which one it should actually be sent to. But since there are no links to that redlink now, it would be better to leave it red and let the people who discover such a redlink determine which pound article it should go to. Gene Nygaard 14:59, 21 September 2006 (UTC)

[edit] Proposed rearrangement

The pound, as a unit of mass or force, needs just one article: pound (weight). Pound (mass) and pound-force should be redirects to it. This article can discuss the contexts in which a pound means mass, and in which it means force, and so forth. So what do folks think about this? By the way, if you're not sure about the use of the word "weight" to cover all meanings of "pound", see weight. Another reason for this change is that the pound-force article replicates some of the information currently in pound (mass). A combined article would nicely present all relevant information in one article of a sensible length. --Yath 13:59, 15 August 2006 (UTC)

The modern distinction between mass and weight, and its development over time, is discussed in the article on Weight. I do not think the proper place for a discussion of that distinction is in an article on one particular unit of mass or unit of force (even if those units, by reason of their long history, happen today to still share the same name). (I do think the articles on the pound (unit of mass) and pound (unit of force) should contain early pointers to that discussion.) Today and for many decades, the pound has been the name of a unit of mass and, in some specialised circumstances, the name of a (conceptually, quite different although not unrelated) unit of force. I would not support recombining Pound (mass) and Pound-force as it seems that some time and effort has gone into carefully separating them.Fibula 23:41, 17 August 2006 (UTC)

You are imaging a "modern distinction" which does not really exist, though it is indeed a figment of the imagination of many science teachers and the like. "Weight" is never a force, when anybody talks about "net weight", for example--and there are billions of examples of that usage today. Of course, "mass", like "weight", is also an ambiguous word, one with several different meanings, but "net weight" is never different from the meaning of mass common in physics jargon but a minority meaning in the usage of the word mass outside of physics. Gene Nygaard 15:06, 21 September 2006 (UTC)

over exaggerations do little to help your argument. (american) engineers and physicists alike will most likely tell you that "weight" is a force. as a physicist, i define weight as the force created specifically by gravitational attraction. in the category of force comes units of pounds and newtons. for a layperson such as yourself, i can understand the confusion for the need to make a distinction between weight and mass. however, it is a necessary distinction (especially in regards to engineering). just because weight is commonly used to denote mass does not make it accurate. —The preceding unsigned comment was added by 72.85.214.147 (talk) 21:37, 11 March 2007 (UTC).

I am new to this discussion, but have taken the time to read everyone's point of view. My opinion is that there should be just one article for these two units, as one is simply an extension of the other. Whether I'm talking about the force I exert on the Earth or the mass of my body, I am still 150 pounds either way. If both units are on one page, it will be easier to discuss the distinction between them than if they are on separate pages. In short, I agree with Yath. --Lasunncty 20:58, 18 September 2006 (UTC)

I'd very strongly oppose such a rearrangement. We need our links to take people to the proper article. We don't need another disambiguation page, which leaves it up to the people clicking on a link to guess which of the two distinct and separate units is being talked about. Gene Nygaard 14:40, 21 September 2006 (UTC)

[edit] Where does lb come from?

Why are pounds called lb in America?--64.121.1.55 20:52, 29 October 2006 (UTC)

They are more correctly abbreviated as lb. From the second line in the Historical origin section:

The word “pound” comes from the Latin word pendere, meaning “to weigh”. The Latin word libra means “scales, balances" and it also describes a Roman unit of mass similar to a pound. This is the origin of the abbreviation “lb” or “℔” for the pound.

MJCdetroit 21:48, 29 October 2006 (UTC)

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