User talk:62.49.16.208

Why are you changing numerous occurances of "centigrade" to "celcius". Whether or not you think the latter is correct, such a change should be discussed on the talk page before doing so. -- Finlay McWalter | Talk 17:06, 8 Feb 2004 (UTC)

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Hey - watch it! It is fine to add metric values to articles, but DO NOT reverse the order of things. If US standard units are given then leave them and place the metric values in parenthesis (and the other way around for that matter). All converted values must be in parenthesis and calculated values need to be outside of parenthesis. Otherwise you are introducing rounding errors into articles and getting accuracy and precision confused. --mav 09:30, 16 Feb 2004 (UTC)

Thank you! :) Much better --mav

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In planetary science, the density of objects is always presented in CGS, not SI, because 1.0 is the density of water. I've never seen it professionally presented in SI (MKS), it looks extremely weird to me. Can you please change back to CGS for density? Thanks! -- hike395 07:42, 9 Mar 2004 (UTC)

I don't know why you have never seen kg/m3 because it is common enough. Just try searching google with the key 'planetary density kg' or any other suitable key. Here are a few examples: http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html http://geosci.uchicago.edu/classes/natsci102/supplemental.html http://www-k12.atmos.washington.edu/k12/modules/fact_notes.html http://www.bradley.edu/las/phy/astronomy/venus.html http://www.psigate.ac.uk/newsite/reference/planets.html http://www.shef.ac.uk/physics/exampapers/2001-02/phy106.pdf http://hyperion.cc.uregina.ca/~astro/ast201/hand_pm/Constants.doc http://www.astro.uu.se/grundutb/labdir/Planetmodeller/README.txt

However, on the basis of your request, I am not planning to make any more changes of this specific kind. I do not plan to search through the ones that I have done and undo them. But if you wish to change them back, feel free, I will not object. I hope that is acceptable to you. Thanks for your welcome feedback.

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Celsius vs. centigrade

Centigrade was changed to Celsius around 1949. I don't think any discussion about making that change is required at all.

I agree. Secretlondon 20:47, 9 Mar 2004 (UTC)

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Please stop turning 'pounds' to 'pound' when we're talking about quantities of multiple pounds, as you did on, say Pratt & Whitney Wasp Major. When 'pounds' is spelled out in full, the plural is DEFINITELY grammatically required in such cases. We do not say 'I weigh 68 kilogram', either. We would use 'kilograms' in that case.

If an abbreviation for a unit is used, then arguably the abbreviation should not be pluralised; this is definitely the case in metric (we never say '300 kgs' because of the confusion with 's' for 'seconds'). However, it is common and not incorrect to use 'lbs' as an abbreviation for quantities of multiple pounds. —Morven 20:43, 9 Mar 2004 (UTC)

Response from 62.49.16.208 You make a fair point with your verbal example. I will no longer remove the plural 's' for units written in full. However with abbreviations (or symbols) as you say, the plural 's' can be mistaken for seconds in and is therefore banned from metric units in symbol form. Although there is no authority that can or has imposed such a ban for non-metric abbreviations, the same logic is reasonable and consistent. Thanks for your feedback.

Thanks for the quick response; that's a version I can live with, since I don't care either way about whether it's 'lb' or 'lbs'. Neither is per se wrong, but if you wish to standardise on the former that's fine with me! —Morven 21:51, 9 Mar 2004 (UTC)

It is not fine with me. Please stop changing lbs. to lb. It may be metric usage but it is not standard English system usage. It is not going to be confused with lb/s (notice the slash and lack of period). Even the U.S. military which uses Metric lists it as lbs. Rmhermen 14:32, Mar 10, 2004 (UTC)

Response from 62.49.16.208 No, it is definitely not 'standard' to pluralise abbreviations of English units(if 'standard' means the vast majority). Try a survey. Wikipedia reports 153 hits for 'lbs' and 216 for 'lb', 11 for 'gals' and 91 for 'gal', 1 for 'length ft ins' and 238 for 'length ft in'. Far from being a 'standard', it may even be the minority style. Interesting debate though, I had never even thought about it till now.

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Are all these changes really necessary? When there are 2 words meaning the same thing, you may as well just leave the original one. Evercat 01:22, 11 Mar 2004 (UTC)

Response from 62.49.16.208 If you are talking about 'micron', it is not very well recognised outside the US (and has not been officially supported and has been officially discouraged since 1968). The word 'micrometre' is recognised throughout the world because of the two easily recognised components 'micro' and 'metre' just as the compound terms microsecond, microvolt, microgram, microfarad are.

Hmm. Well, fair enough, I suppose. Honestly though, I wouldn't worry about it. I think it will take you a long time to change every page... Evercat 01:32, 11 Mar 2004 (UTC)

Response from 62.49.16.208 There were only about a dozen or so and it took only a few minutes. All done now.

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Whoa there chief, no need to go absolutely crazy here. I mean, adding metric conversions to some things is great, and in a lot of cases its probably better to actually change standard to metric, but do we really need to know (or care) what the rating of a 1,000 hp WWII plane engine is in kilowatts?

More seriously though, in some cases (as others have noted) SI is not always the standard in all fields. In biochem or mol bio, Daltons are always used and always correct (more often expressed as kilodaltons); never amu, and never u. For that matter, I don't recall seeing u used instead of amu in other fields, but I can't make any claim to certainty on that. I would refer you to any (and I mean any) paper or textbook covering protein chemistry, or indeed to the very page you linked:

In the field of biochemistry, the unified atomic mass unit is also called the dalton, symbol Da.

-TimeLord mbw 17:55, 17 Mar 2004 (UTC)

Response from 62.49.16.208 (actually Bobblewik)
There is rarely universal geographical agreement about units, and which are local to a particular professional domain or a particular part of the world. The age of the system being described (e.g. a 60 year old aircraft) surely does not have any relevance to whether the reader of today understands the units in the text.

People outside the US definitely do value having metric equivalents so that they can understand what is being said. There is little reason to argue against providing metric information. I note that you seem to be making a similar point in your second sentence. However, if you are also suggesting that the unit 'watt' is not (or rarely) applied to engine power, or that amu is not (or rarely) used, then simply try the crude google test. A google search for

'engine kW OR kilowatt OR MW' returns 917,000 hits

'engine hp OR horsepower' returns 3,280,000

'atomic mass amu' returns 39,200 hits

'atomic mass Da OR kDa' returns 173,000 hits

That seems to indicate that the metric units are far from rare in those applications. They seem to be in widespread use, particularly considering that the web has a bias towards US sources.

In response to your comments, I have no further plans to focus on units of atomic mass. I hope that you will forgive me for continuing to provide people in the metric world with the benefit of watt values for power. I appreciate the discussion Bobblewik 17:36, 18 Mar 2004 (UTC)

As far as engine ratings, I don't doubt that kW are widely used outside the US, and may well be more familiar to some people, and should probably be included (at least as a conversion) in some circumstances. My problem with the particular instance I mentioned is that an engine rating is just that, a rating, not a measurement. I'm probably going to have a hard time expressing this exactly--742 kW implies a level of precision that 1,000 hp does not, a level of precision that is most likely not warranted.

If you'll excuse a hyperbolic analogy: If I tell you something's about six inches long, and then you report to another person that it's 15.24 cm long, then, while the conversion is technically correct, you're implying a level of precision that isn't warranted. Even if you say it's "about 15 and a quarter centimeters" or even "about 15 centimeters", that still implies something different than "about six inches". Put it this way, when I see 1,000 hp for an engine, I don't assume that the engine always produces exactly 1,000 hp. But if I see 742 kW, then I do assume that the true number is very close to that.

That said, if there are people who have a better "feel" for kW than hp, then the conversion may well be worth including, in which case I'm not sure how (or if there is a way) to fix the implied level of precision.

Back to atomic mass--to be honest, those numbers surprise me; I would not have expected Da to outnumber amu at all.  :-) I certainly never meant to imply that "amu" or even "u" were rare terms, or that "Da" is always preferred. I know from experience that "amu" is common outside of protein chemistry, and it may well be that "u" is beginning to supercede it, since it is now the preferred SI symbol.

What I took issue with was labelling "Da" incorrect, with the implication that "u" is always correct. I rarely say always, but protein masses really are always referred to in Daltons, and that usage is at least acknowledged by the SI. And regardless of SI approval, I think we would be doing a disservice to someone looking for information to give them the notion that "Da" is completely outmoded when (rightly or wrongly) it is the usage of choice in the modern literature of a particular (and important) field.

As far as generally substituting "u" for "amu"; I don't know, and don't pretend to be an authority. I would actually be interested to hear someone else speak on which is more commonly used in the present literature. However, I do strongly believe that substituting "u" for "Da" in reference to a protein mass would be a mistake (not that I've seen you or anyone do this; just a for instance).

As I said, in general, inserting metric conversions is useful for people who "think" in metric. However, I do worry that in some circumstances a "literal" conversion implies more precision than is warranted. I also question in some (mostly specialized, or historical) cases whether the conversion is necessarily useful to anyone. But, for the most part, bravo, and have at it. -TimeLord mbw 19:12, 18 Mar 2004 (UTC)

(Sorry for the massive post.)

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