User:Kernigh/pound

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This page is part of a comment by Kernigh on Talk:Wikijunior Solar System/About gravity, mass, and weight.


Over at Talk:Guide to UNIX/Linux, from February 2005 to July 2005, there was a debate between the names "Linux" and "GNU/Linux", which describe a computer "kernel" or "operating system". Like "weight", "operating system" is ambiguous; like "pound", "Linux" might refer to two different but related things. There is also a Wikipedia article, w:GNU/Linux naming controversy, about that dispute.

  • Pound is force: Now let me bring your attention to w:slug (mass). Applying 1 pound of force to 1 slug accelerates it at 1 foot/s/s; this is similar to how applying 1 newton of force to 1 kilogram accelerates it at 1 meter/s/s. Thus in some contexts, "pound" is force and "slug" is mass. The book Physics for Scientists and Engineers, 5th edition, Volume 1 (ISBN 0-7167-0809-4) describes the pound: The pound was originally defined as the weight of a particular standard object at a particular location. It is now defined as 4.448222 N.
  • Pound is mass: In contrast, for the purposes of commerce in the United States, the definition written into the United States Code is exactly 0.45359237 kilograms to 1 pound. (Search the code for "pound kilogram" and look at "15USC Sec. 205. Authorized tables".) In fact, article 1, section 8, of the US Constitution gives to Congress (the federal legislature) the authority to define measurement units in the United States.
  • One-pound policy: For the two definitions to be consistent, the acceleration due to gravity must be 4.448222/0.45359237 m/s/s which is about 9.80663 m/s/s, or almost the same as the "standard value" of 9.80665 m/s/s found at w:Gravity. The two definitions are not consistent because this Wikijunior module attempts to give weights on the moon and planets where the acceleration is much different from 9.8. Thus, one possible approach is to debate whether "pound" refers to mass or weight and adopt a one-pound policy which requires that a pound only be mass, or only be weight, but not both. This is as if all references to "Linux" in the module must be changed to "GNU/Linux", or all "GNU/Linux" to "Linux". With this approach, there is one correct kind of "pound" and one incorrect kind.

The problem with that version of the one-pound policy is that it requires the determination that one kind of pound is incorrect. I disagree that one kind of pound is incorrect. A pound is a unit of mass sometimes and a unit of force sometimes, just as a certain operating system is Linux sometimes and GNU/Linux sometimes. Thus I support this version of the one-pound policy: There is only one pound, but it has two definitions. I have wasted five paragraphs to make a trivial assertion about a naming problem. I oppose the idea that references to pound as mass, or pound as weight, must be corrected. See User:Kernigh/pound for details. --Kernigh 03:28, 24 October 2005 (UTC)