Talk:Conversion of units/Archive 2011

External links

I would like to add an external link to http://sooeet.com/index.php, an online converter for most of the units of measurement presented in this article. The tool additionally provides a very capable scientific calculator, which incorporates the unit conversion results via calculator memories, along with a fairly complete set of physical constants. I find the combination of features very useful in my work, and other users of Wikipedia would likely benefit as well. I have verified as accurate all of the important conversion factors for the physical quantities of length, area, volume, temperature, speed, weight, mass, angle, force, torque, acceleration, energy, power, and frequency, in relation to the factors presented in this article, and elsewhere on Wikipedia, including the annotated references, (i.e. the factors I use most often in my work.) I have also verified the accuracy of the scientific calculator results, using converted measurements via the memory feature, and many of the physical constants provided in the calculator. The tool additionally provides conversion factors not covered in this article, and although I have not verified the accuracy of all the conversion factors provided by the tool (only the ones I mentioned earlier), the fact that a significant portion of the tool delivers consistent accuracy, leads me to conclude that the entire tool is likely accurate to the same degree. Blakecity (talk) 02:40, 11 January 2011 (UTC)

Wikipedia isn't meant to be a link farm. I'd feel awfully silly sitting in a witness box testifying "Well, the two or three things I tried looked all right for the numbers I used and could remember, so I just naturally assumed the whole site was 100% accurate all the time. After all, it's on the Web!". People who need a Web app to do multiplication should be gently diverted to the sand table where they won't hurt themselves. --Wtshymanski (talk) 14:29, 11 January 2011 (UTC)

External links

For years this article has included several external references to entire directories of online conversion tools, or "Web apps" as described by Wtshymanski, presumably designed for conversion of measurement units, as implied by the link text of those external references. However, there is no indication in the article body, or in the discussion notes, that the referenced "Web apps" were vetted in any way, shape, or form by Wikipedia editors, or by anyone else for that matter, yet those external references have stood the test of time, and have remained in the article for years. To my knowledge, Wikipedia does not place a numerical limit on the number of external references that an article may contain, and so I proposed to add an external reference for a conversion tool that was indeed vetted, and directly addresses the topic of this article (http://sooeet.com/index.php). Wikipedia users should have the right to decide for themselves, whether or not a particular resource such as a "Web app", is appropriate for their needs. As such, Wikipedia should make resources available to users whenever those resources are appropriate to the article, and do not violate the written Wikipedia editorial guidelines. In other words, Wikipedia editors must exercise the editorial guidelines equitably, fairly, and reasonably, specifically avoiding arbitrary judgments and personal bias. With regards to vetting, the existing external references in this article, to directories of software and online conversion tools, are certainly not vetted scientifically. The well-known general-purpose directories currently referenced by this article, cannot and do not vet scientific references for accuracy, due to the large volume of submissions they receive, and due to the fact that they are not scientific institutions and do not employ scientists to vet their references. Their vetting is limited strictly to general editorial guidelines, which have nothing to do with scientific value, and only look to avoid certain prohibited content and practices. Therefore, as a Wikipedia editor, if you choose to block the inclusion of the vetted reference I proposed, please explain in objective, unemotional detail your reasons for blocking this reference, and on the other hand your reasons for endorsing, and not objecting to, the continued inclusion of entire directories of similar references that have not been vetted. When considering your reply, note that this discussion now transcends the topic of the article, due to the arbitrary and emotional objection by another editor (see "Wtshymanski (talk)"). That objection has opened the door to the larger question of the quality of editors at Wikipedia, and whether or not the editors are motivated by reason, by personal bias, or by pathological factors fundamentally inappropriate to editors. Blakecity (talk) 22:22, 11 January 2011 (UTC)

Too long, didn't read. Check out WP:EL. Vetting by a Wikipedia editor is about as valuable as vetting by the guy sitting on the next bar stool. And again, people who need to use the Internet to convert firkins to pottles are just going to find some other way to hurt themselves if we take away the external links here. --Wtshymanski (talk) 22:36, 11 January 2011 (UTC)

I cannot respond to Blakecity (talk), like Elvis -- he came, he saw, he went - see [1]

Removal of variable suggestions

I have removed the variable suggestions for several reasons.

• No reference was provided to show these were the correct variables to use.
• No explaination was provided to show these were variable suggestions.
• The variable used for a certain quantity can vary from one field to another.
• Some of the variables for scalar quantities were in boldface, which often is reserved for vectors.
• Most of the variables were in upright type, but variables are usually put in italic type. --Gerry Ashton (talk) 20:17, 22 January 2008 (UTC)

PLEASE CAN SOMEONE DO A USEFUL CONVERSION TABLE FOR THE LAY PERSON! I'm sorry that this comment may not belong here, but I didn't see where else to put is. Please let me know where would be better. I've been doing editing for Wikipedia for a number of years on different topics - certainly not mathematics.

But we REALLY need a USEFUL conversion table. I was simply trying to convert 120 ml to oz., and it is REALLY difficult with the current conversion table. (Actually, I'm not sure if it is even possible with the current table, which is pretty sad.)

Could someone please help?

Thanks very much.

Kris Wood sfbaybreezes@yahoo.com — Preceding unsigned comment added by Kristinamwood (talk • contribs) 21:49, 2 April 2011 (UTC)

Length conversions not adding up (1 mile = 1.609344 kilometers?)...

........It seems to me that the conversion to and from Standard and Metric should be fairly easy for things such as length. For example, a basic Standard unit is the inch, and a basic Metric unit is the centimeter. To convert between them, 1 inch equals 2.54 centimeters, and one centimeter equals .3937 (plus a tiny bit more) inches, and there doesn't seem to be any disagreement on this.

........There are 12 inches in a foot, and 5280 feet in a mile. So, one mile is 63,360 inches. One kilometer is 100,000 centimeters. 100,000 divided by 63,360 is 1.5782, so one mile should equal 1.5782 kilometers, and one kilometer should equal .6336 miles.

........So, my question is, where exactly do we get the figure of 1.609344 kilometers per mile? That isn't even close. The impetus for this post is that I was a short while ago attempting to calculate the circumference of VY Canis Majoris, which is ordinarily measured either in AUs, or in thousands of solar radii, and I've learned from experience that I unfortunately cannot trust the figures given on Wikipedia to be accurate representations of values given in miles. When you're dealing with converting thousands of solar radii to miles, the difference between 1.5782 and 1.609344 can add up very quickly. So, I'm just wondering, where is it that we get the latter value from, and why isn't it simply a matter of the multiplication and division of inches and centimeters to ascertain the conversion values for other Standard and Metric units? Any input or insight anyone can offer would be much appreciated. <smile> -=( Alexis ^(talk)23:17, 1 August 2011 (UTC) )=-

A mile is 63,360 in × 2.54 cm/in ÷ 100 cm/m ÷ 1000 m/km = 1.609344 km. JeffConrad (talk) 23:31, 1 August 2011 (UTC)

To follow up and expand on Jeff's answer, this is what you've done (hint: look at the units):

100,000 cm/km ÷ 63,360 in/mi = 1.5782 cm/km · mi/in

We can rearrange the units to display as

1.5782 cm/in · mi/km

To get to a miles/kilometers equivalence, we need to get rid of the cm/in, so:

1.5782 cm/in · mi/km × 1 in/2.54 cm = 0.62137 mi/km (roughly)

When we take a reciprocal of that, we get 1.609344 km/mi

(In short, you left out the inches-to-centimeters conversion.) BW95 (talk) 03:14, 2 August 2011 (UTC)

Um, no, I don’t think so: “63,360 in × 2.54 cm/in”. JeffConrad (talk) 03:48, 2 August 2011 (UTC)

I was addressing Alexis's original question. He or she had left out the cm/in conversion and ended up with the wrong number. BW95 (talk) 04:12, 2 August 2011 (UTC)

So I now see. JeffConrad (talk) 05:04, 2 August 2011 (UTC)

Conversion of RPM

can somebody please tell me the SI unit for R.P.M — Preceding unsigned comment added by 82.128.13.136 (talk) 09:38, 12 October 2011 (UTC)

RPM would be converted to hertz. Each revolution would be considered a cycle, so just divide the RPM by 60 to find hertz. If this is being done for an electric generator, keep in mind that one revolution of the rotor may produce several cycles of electric energy. Jc3s5h (talk) 14:27, 12 October 2011 (UTC)

External links

I came here from a site that have a complete list of online unit converters: http://www.webqc.org/unitconverters.php Would it be a good addition to external links or do we avoid them because of DMOZ reference which for some reason is missing it? ~~Julia — Preceding unsigned comment added by 75.208.35.32 (talk) 10:12, 16 December 2011 (UTC)