Talk:Kilogram/Archive 2

message: Bravo to User:Greg L for doing some needed heavty-duty article improvement in the past days.   I do have one suggestion; I know it is generally accepted to start with a History section, but it feels to me as if this article jumps in too hard and too fast to details most people will skip right over.   I suggest a different organization.  How about we start first with what is now "Link with weight," rename it to something like "Common use" and put the lead section approximate weight and some other example masses (like gram does) in this new section.  How does this sound?  
On a side note, do the current "examples" in "link with weight" belong in "SI multiples?"  Enuja 19:06, 11 August 2007 (UTC)
replies: text: Thanks for the ‘attaboy’ Enuja. I saw all that disorganized stuff below (“Ugh” factor) and let it lie. I had already spent more time than I bargained for making the computer-generated ray-tracing and editing all that text. Given your prompting, I waded in again. Fixing the rest necessarily entailed the removal of some rather spurious writings, which I am loath to do as it often results in revertings that undoes a lot of hard work. I’ve revised and reorganized everything from the opening definition through “Stability of the International Prototype Kilogram.” I think the article reads better now; it’s certainly makes more accurate and factual statements.  Greg L (my talk) 18:01, 12 August 2007 (UTC)
thread_title:  Bravo & a proposal 

message: Wikipedia’s official policy is that the spelling convention used by the first major contributors should be retained. The Kilogram article is written throughout with American spelling (kilogram instead of kilogramme, liter instead of litre). Note the following passage, taken from Wikipedia:Manual of Style:
Note that “liter” is the proper American spelling. Note further that two other instances of liter are elsewhere on the page. Please also take note of another common-sense policy from Wikipedia:Manual of Style:
Accordingly, your insistence at “correcting” this one instance just makes the article non-harmonious. It would be highly inappropriate of you — and against Wikipedia policy — to go through the entire article to change the rest of the article to British spelling.
As regards consistency from article to article within Wikipedia, there is none. Note the Pressure article. It uses British spelling throughout. Further, if you click on a link in the article spelled centimetre (of water), you go to an article titled Centimetre of water wherein the spelling within the article uses the “centimeter” spelling!
Wikipedia’s policy (that the spelling convention used by the first major contributors should be retained) seems a good one. It encourages contributors to begin or substantially expand articles. Further, it reduces frustrations for contributors such as when someone later wades into an article (like the Kelvin article, which uses American spelling throughout) and changes “color” to “colour.”
Please adbide by these policies.
P.S. On a final note, I’m not entirely ‘hung up’ on American conventions. For instance I used the European date convention of “7 April 1795” in the History  section. It is such a steaming logical way of doing it and eliminates a comma. And although I am an American engineer, I do all my primary design in SI units and only convert to inches etc. at the last step when generating prints for machine shops or writing an owners manual. (19:09, 13 August 2007)
Greg L (my talk) 18:41, 13 August 2007 (UTC)
replies: text: *Thank you. I appreciate your flexibility. Our recent edit/edit/edit, while rarely enjoyable, resulted in an improved opening definition.  Greg L (my talk) 19:09, 13 August 2007 (UTC)
thread_title: Spelling: National conventions

message: a quantity "having originally been defined relative to this volume of water" could have been "relatively" defined as half that volume. More information is conveyed by the statement (similar to one long included in this article) - that it is "almost exactly equal to" the mass/weight of 1 L of water.
:JimWae: You're right. Done.  Greg L (my talk) 20:45, 13 August 2007 (UTC)
thread_title:  having originally been defined relative to this volume of water. 

message: Wow, I go away on a measly 3 day vacation to (the excellent) Zion National Park, and this article improves by leaps and bouds!  How exciting.  Honestly, I've only had it watched to keep it from getting any worse; although this article certainly needed serious work a week ago, I wasn't planning on doing any of it.  Bravo again to Greg L for doing so much work on this! 
Philosophically, I think that this article should do a quick sketch of the mass v. weight issues, and direct readers over to weight.  However, the current mass v. weight section has some details and approaches that are better than the treatment at weight.  Personally, I think that User:Greg L should put that section in his user space, we should re-organize this article, and Greg L should edit his stuff into weight to make it excellent as well. 
Here is a proposal for the organizational scheme: 
  ==Common Use==
 ===Mass versus weight=== link to main article (weight, yes?) contents of current "the distinction between the two" subsection
 ===Converting mass to weight === contents of "unit of measure for weight" and current subsections, shortened and put together
 ==History== (complete with current subsections)
 ==Stablity of the International Prototype Kilogram==
 ==Proposed future definitions== (complete with current subsections)
 ==SI multiples ==
 ==See also==
 ==References==
 ==External links== 
This would remove the current section "The nature of mass" and the contents of the subsections "Effect of bouyancy" and "Types of scales and what they measure," and I'd also like to work on streamlining much of the new content to be a short and readable as possible.  How does this organization sound to everyone?
I'm also going to play around with the lead section; everyone, feel free to revert me or fiddle with it.  I tried to do a long talk page post last night with lots of detailed wording proposals, but the computer I was using restarted in the middle of the process, so I'm just going to try doing before talking.  I'm very willing to talk after doing.  Enuja 23:45, 15 August 2007 (UTC)
thread_title:  Proposed organization 

message: I have nominated Template:SI multiples (transcluded or subst'ed in this article) for deletion on WP:TFD. Han-Kwang (t) 16:07, 23 August 2007 (UTC)
thread_title:  SI multiples 

message: This section of the article is presently more about force than about either mass or kilogram. Nothing AFTER the 2nd sentence is about the "nature of mass".
1st sentence fine:
*The kilogram is a unit of mass.
Alternative 2nd sentences:
*Mass is an inertial property; that is, the tendency of an object to remain at constant velocity (which may be zero) unless acted upon by an outside force. 
*Mass is an inertial property; that is, the tendency of an object to remain at rest or at constant velocity unless acted upon by an outside force.
The rest is not about mass - and certainly not about the nature of mass: 
*An object with a mass of one kilogram will accelerate at one meter/second² (about one-tenth the acceleration of gravity) when acted upon (pushed by) a force of one newton (symbol: N). Note that the newton is the SI unit of force. In fact, the newton is defined by the kilogram: the newton is the force required to accelerate an object with a mass of one kilogram at a rate of one meter/second². Accordingly, if the mass of the International Prototype Kilogram were to change slightly, so too must the newton by a proportional degree.
--JimWae 06:04, 24 August 2007 (UTC)
replies: text: Whatever. Knock yourself out. I don't like battling over ever little edit. “([A velocity] which may be zero)” is precisely identical to “remain at rest.” Except that the latter certainly seems less awkward to me. It’s either moving (at a constant velocty), or it’s stationary.Greg L (my talk) 20:50, 24 August 2007 (UTC)
replies: text: I think Jim's point is that being at rest is a subset of moving at a constant velocity, not something different from moving at a constant velocity.  And I agree that it's important to avoid giving anyone the impression that being at rest is not moving at a constant velocity.  Enuja 23:30, 24 August 2007 (UTC)
thread_title:  The "nature" of mass 

message: Actually I do prefer the 1st to the 2nd. Saying "to remain at rest or at constant velocity" makes it seem like there are 2 separate possibilities - whereas saying "remain at constant velocity (which may be zero)" does not treat "at rest" as being somehow a separate state of affairs
--JimWae 06:04, 24 August 2007 (UTC)
replies: text: Whatever. Knock yourself out. I don't like battling over ever little edit. “([A velocity] which may be zero)” is precisely identical to “remain at rest.” Except that the latter certainly seems less awkward to me. It’s either moving (at a constant velocty), or it’s stationary.Greg L (my talk) 20:50, 24 August 2007 (UTC)
replies: text: I think Jim's point is that being at rest is a subset of moving at a constant velocity, not something different from moving at a constant velocity.  And I agree that it's important to avoid giving anyone the impression that being at rest is not moving at a constant velocity.  Enuja 23:30, 24 August 2007 (UTC)
thread_title: re alternative 2nd sentences

message: "The unit of weight" is not the kilogram-force, at least in the SI system.  A weight is a force, and therefore the SI unit of weight is the newton.  As its page says, the kilogram-force is non-SI.  Personally, I think it belongs in the article, but not in the lead.  Enuja 00:34, 25 August 2007 (UTC)
thread_title: SI Unit of weight

message: JimWae: You originally had
While this isn't incorrect (with respect to “accelerating,”) it is misleading. That’s why I changed it to…
You reverted it by stating the following in the edit comment: “if velocity was constant at 90% c, mass would still be constant in that frame of reference”
OK. What you appear to be asserting is that the mass of matter not only increases as it approaches light-speed, but even though it has this relativisticly inflated mass, it is still a stable—though inflated—value. Why in the world would you write something so obscure in this article? It's already obscure enough in that it is an exception for relativistic effects but now you're trying to talk about variable relativistic effects!.
Note that anytime an object has no relativistic velocity with respect to an observer, it has normal “rest” mass. If the object is traveling with respect to an observer at a high, relativistic speed, its mass is substantially increased. To use your example of 90% the speed of light, the object would have a γ of 2.29415 and, accordingly, would have a mass (m) of over twice its rest mass (m0). This is more than an abstract, theoretical situation: the mass of muons entering a laboratory from high in the atmosphere display spuriously long lifetimes—and relativisticly high mass—due to their velocity. This is a reasonably important point to make, that high velocities changes the mass of matter. It logically follows that accelerating at near the speed of light is a variable amount of this mass dilation. Jumping over the first effect (traveling near the speed of light changes mass) and going directly to the next effect (accelerating near the speed of light has a variable change of mass) is just confusing. The whole point of technical writing is to educate, not confuse the typical reader with way-abstract points.
In hopes of achieving yet another compromise with you, I've changed it to “traveling near the speed of light.” It avoids nailing the issue down to just “velocity,” while dodging the potentially misleading added specificity of “accelerating.” Please also consider allowing the change from “object” to “matter.” This permits the deletion of “gaining atomic material” and similar caveats. As you can see, it conveys the same concept, just in a much more compact way.
As regards your wondering about this ‘newton thing’ (OMG!), that's the very definition of the kilogram. Along with the units for acceleration, it adds extra specificity to mass, acceleration, and force. It solidly deserves to be in this Wikipedia article.
Greg L (my talk) 04:18, 30 August 2007 (UTC)
replies: text: That's true. In fact, what I originally had in the paragraph is that the newton was actually defined by the kilogram. However, you deleted that because because you felt it made the section too much about the newton. What is writen there now is 100% true and is not misleading. It simply adds some much-needed specificity the basic concept that already there in the paragraph: that the kilogram has inertia and will accelerate only when acted upon by a force. Greg L
*objects travelling at a constant velocity have a constant mass - it is misleading to leave open the suggestion that mass is not constant at 90% c if velocity is constant - --JimWae 05:18, 30 August 2007 (UTC)
replies: text: That's an obscure argument that most readers will be mislead by. The mass of matter at 99.499% the speed of light has ten times its rest mass, but you want to say “But—though ten times greater—it’s still constant! Why would anyone want to put such an obscure point in the article?!? Greg L
*"constant velocity (including zero)" makes it clear that rest is just a special case of constant velocity, while "at rest or at constant velocity" can easily be interpreted (as I did when I forst heard this) as 2 separate possibilities - almost as if they could "jump" to one state or the other. Another editor has agreed on this point. Articles are not individual projects.--JimWae 05:31, 30 August 2007 (UTC)

text: That was a compromise because you had a problem with just “constant velocity” (which is the wording that any physics book uses and seems to communicate clearly enough to children). I restored it to the classic, textbook example children read. I just hope you don’t do what you did before: add “or decelerate” after  the word “accelerate.” The definition of words in physics shouldn’t have to change because JimWae says so. Greg L
*if we are going to have a section on "the nature of mass", then the fact that the mass of an object changes when it accelerates near c is something that should be noted in that section. Alo notable there is loss of mass when it is converted to energy in radioactive decay. --JimWae 05:44, 30 August 2007 (UTC)

text: Regarding the “radioactive decay”part (wherein energy is always radiated away): In that case, some of the matter has disapeared. That's the beauty of speaking in terms of “matter” instead of “an object.” “Matter” has constant rest mass. By using logical words, one avoids awkward caveats like “assuming it [an object] has not lost or gained any atomic material.” As regards the rest of the above statement, Enuja: Weigh in here. Please. Editors are asked to be mindful that Wikipedia policy (see Wikipedia:Lead section) is that articles on technical subjects, and in particular their lead sections, should be as generally accessible as possible for the subject matter. Now JimWae wants to add to a lead section about relativistic effects and how, if one changes their velocity at near-light speed, that this has a changing effect on relativisticly dialated mass. Good grief. Greg L (my talk) 17:12, 30 August 2007 (UTC)
thread_title: Relativity’s effect on mass

message: :Which weights [sic] more, a ton of lead or a ton of aluminum? Thanks. I corrected the spelling error. Greg L (my talk) 23:14, 1 September 2007 (UTC)
replies: text: * JimWae: Here’s an edit made today to the Mass vs. weight section by an unregistered editor (I.P. address-only): the difference.  In this case, the editor obviously read the section and appreciated it enough to spend the time addressing the very issue you raised.  Greg L (my talk) 22:05, 6 September 2007 (UTC)

text: * I retracted my ‘don’t care’ statement and added a better-articulated position. See above.  Greg L (my talk) 22:50, 6 September 2007 (UTC)
thread_title:  No source for .. 

message: Some rationale can be made for a section distinguishing mass from weight in the mass article, the weight article, and perhaps even in the kilogram article - but little if any case has been made for distinguishing 2 (or 3) types of weight (weight in vacuum, vs weight in air, vs weight in any fluid) in the kilogram article. Such distinctions belong in the weight article. Our new contributor continues to make massive edits (some good, several incorrect or misleading) to the article & ignores (per:"I'm not interested in what a (very) small group of regular editors feel") all pleas for sober second thought here. He justifies his editing of others' contributions with arguments he rejects when others try to apply those arguments to his edits --JimWae 18:00, 1 September 2007 (UTC)
replies: text: * I retracted my ‘don’t care’ statement and added a better-articulated position. See above.  Greg L (my talk) 22:50, 6 September 2007 (UTC)
thread_title: overall