Wikipedia talk:WikiProject Measurement

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WikiProject Measurement (Rated Project-class)
WikiProject icon This page is within the scope of WikiProject Measurement, a collaborative effort to improve the coverage of Measurement on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
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Article alerts[edit]

This is a notice to let you know about Article alerts, a fully-automated subscription-based news delivery system designed to notify WikiProjects and Taskforces when articles are entering Articles for deletion, Requests for comment, Peer review and other workflows (full list). The reports are updated on a daily basis, and provide brief summaries of what happened, with relevant links to discussion or results when possible. A certain degree of customization is available; WikiProjects and Taskforces can choose which workflows to include, have individual reports generated for each workflow, have deletion discussion transcluded on the reports, and so on. An example of a customized report can be found here.

If you are already subscribed to Article Alerts, it is now easier to report bugs and request new features. We are also in the process of implementing a "news system", which would let projects know about ongoing discussions on a wikipedia-wide level, and other things of interest. The developers also note that some subscribing WikiProjects and Taskforces use the display=none parameter, but forget to give a link to their alert page. Your alert page should be located at "Wikipedia:PROJECT-OR-TASKFORCE-HOMEPAGE/Article alerts". Questions and feedback should be left at Wikipedia talk:Article alerts.

Message sent by User:Addbot to all active wiki projects per request, Comments on the message and bot are welcome here.

Thanks. — Headbomb {ταλκκοντριβς – WP Physics} 09:23, 15 March, 2009 (UTC)

I need your help[edit]

Hi metrologists, I ask for your help. I am stalked by two Chemists that unfortunately have no clue about metrology. I try to make sure that articles are written in correct metrological terminology. Now they are planing to ban me again (see here User_talk:Kkmurray/1). I hope you guys can see that his article Kendrick mass is full of incorrect language (even though it is all taken from reviewed papers) and that my article Kendrick (unit) is better.

Here you find the whole story of the current argument: Talk:Kendrick_mass.

We had an argument before on which they achieved to have me banned for one year. I still think this ban was incorrect. The argument was about a physical quantity in mass spectrometry, the mass-to-charge ratio. Some in the chemistry branch of mass spectrometry use a "dimensionless" m/z and my claim is that a mass-to-charge ratio by definition cannot be dimensionless and therefore needs a unit and that a symbol m/Q would be more appropriate. I partly won the argument because my article Thomson (unit) is still alive.

The deeper issue on this new argument is that many chemists seem not able to make the difference between a quantity Q = n * unit, and the numerical factor n of a quantity. Please check yourself and I would really appreciate your support here Talk:Kendrick_mass. Kehrli (talk) 31 October 2010

Comments on the article “Natural Units”[edit]

When we measure a value of a quantity with an object O we describe an objective property of that object that does not depend on our choice of unit. So, for instance, the mass of by body is the same in London, where an old fashioned system of units is used, and in Paris, where masses are expressed with the help of the unit kg. It is an objective property of my body.

Generally, values of quantities are elements of linear spaces, and as such, they can be written as linear combinations of basis elements. When we change the basis, the coefficients of the linear combination that describes a value will change contravariantly so as to keep the value invariant. In the special case of a one-dimensional quantity, the basis has only one element and this is called a unit. Our equations that describe physical laws relate invariant values of several quantities. Consequently these equations are also invariant. No change of unit will change the aspect of the equations and especially no constants will disappear with a special use of units.

So if we use the mass value mp of a proton as the mass unit, the mass value of a proton will be 1 mass unit and not the number 1, as is stated in the article. The symbol mp will not disappear from the equations. What eliminates constant values from the equations is not a special choice of units but a change or a redefinition of quantities. So if mO is the mass value of an object O , we can define a new quantity with numeric values such that the value attributed to the object O is m*O=mO/mp . This is a new quantity that describes a property of a pair of objects; <object O, proton>. But as long as we keep the second object fixed, this quantity can also be considered as a new definition of the mass. With this new definition of mass, the symbol mp will disappear from the equations. Coincidently, the reference object “proton”, which was used in order to define the new mass quantity, could also have been the object that defined the unit of the old mass quantity. But a redefinition of a quantity and a choice of unit are different things. Not always the redefinition of a quantity that eliminates constants needs a reference object. The redefinitions of quantities that make the symbols c (invariant speed) and hbar (Planck constant) disappear are not induced by a choice of reference objects. I shall discus the case c=1 as an example, because this case is an especially interesting one. Here I shall restrict my arguments to a space-time region where gravitational effects can be neglected and special relativity is sufficient to describe space-time geometry (the general case is discussed in Studies in History and Philosophy of Modern Physics 47, (2014) 107-116; http://dx.doi.org/10.1016/j.shpsb.2014.06.002).

Let A and B be two fixed points in the space of a given inertial reference frame. Imagine we install two identical atomic clocks CA and CB in these points and these clocks remain stationary at the respective points. We need two more atomic clocks of the same type, but these clocks will move in space with the kind of motion that is characteristic of free particles. The first of these traveling clocks passes through the point A and later through the point B. This clock will measure a certain traveling time τ between the events of reaching the points A and B. After the arrival of the traveling clock 1 at point B we send the second traveling clock in such a way that it passes through point B and afterwards through point A. The traveling speed of this second traveling clock shell be adjusted such that this clock will also show the same traveling time τ as the first one. Let tA1 be the time shown by clock CA when the first traveling clock passes point A. Let tB1 be the time shown by clock CB when the first traveling clock passes point B. And correspondingly, let tA2 and tB2 be the times shown by the respective stationary clocks at the respective passages of traveling clock 2. Then one can verify experimentally that:

(1) The value ((tA2-tA1-tB2+tB1)22)1/2 depends only on the points A and B. It does not depend on the traveling speed of the traveling clocks! If one measures this quantity for many pairs of points one may determine a function:

D(A,B) = ((tA2-tA1-tB2+tB1)22)1/2

(2) The function D defines a Euclidean metric in the space of the inertial frame.

(3) The ordinary distance d, which is defined with the usual measurement procedures using compasses, is proportional to D, that means the quotient d(A,B)/D(A,B) does not depend on A and B.

These observations allow us to substitute the ordinary distance d by the new function D. If one does that, other quantities such as the speed also get replaced. The new speed quantity will have values in the set of real numbers and the invariant speed c will have the value 1.

In this construction of new quantities no reference object has been used. Also the equality c=1 has absolutely no relation to a special choice of units. You may even use your old units second and meter. Ask the director of the museum in Paris for permission to measure the distance of the scratch marks on the meter bar with the atomic clock method. Probably you will get a value with considerable experimental uncertainty and the value will be something like 3.3×10-9s. Then you may call this a meter. But you may also define a meter to be 1m=1s/299792458. You may do with the units whatever you want; the relation c=1 does not depend on it.

So we see that “use of natural units” is an inadequate term for the procedure to eliminate certain constants from the physical equations.

The article gives the impression that scientists are cheating. The “setting a unite equal to one in parenthesis” without any explanation of the exact meaning gives this impression. We cannot simply set something equal to 1. The symbol “=” has a very definite meaning. One more comment concerning the fine structure constant: Let me first recall what the fine constant is: this constant is 2π times the electrostatic energy of two electrons separated by a macroscopic distance d , divided by the energy of a photon of wavelength d. This gives a measurable number and with electrons in our galaxy one finds 7.29735289(53)×10-3. The fact that 1=7.29735289(53)×10-3 is not a valid formula has absolutely nothing to do with the question which other constants one would like to set equal to one! 200.17.69.109 (talk) 18:59, 12 February 2016 (UTC) (Signature moved; Imaginatorium (talk) 03:48, 13 February 2016 (UTC))

WikiProject X Newsletter • Issue 7[edit]

WikiProject X icon.svg
Newsletter • February 2016

This month:

One database for Wikipedia requests

Development of the extension for setting up WikiProjects, as described in the last issue of this newsletter, is currently underway. No terribly exciting news on this front.

In the meantime, we are working on a prototype for a new service we hope to announce soon. The problem: there are requests scattered all across Wikipedia, including requests for new articles and requests for improvements to existing articles. We Wikipedians are very good at coming up with lists of things to do. But once we write these lists, where do they end up? How can we make them useful for all editors—even those who do not browse the missing articles lists, or the particular WikiProjects that have lists?

Introducing Wikipedia Requests, a new tool to centralize the various lists of requests around Wikipedia. Requests will be tagged by category and WikiProject, making it easier to find requests based on what your interests are. Accompanying this service will be a bot that will let you generate reports from this database on any wiki page, including WikiProjects. This means that once a request is filed centrally, it can syndicated all throughout Wikipedia, and once it is fulfilled, it will be marked as "complete" throughout Wikipedia. The idea for this service came about when I saw that it was easy to put together to-do lists based on database queries, but it was harder to do this for human-generated requests when those requests are scattered throughout the wiki, siloed throughout several pages. This should especially be useful for WikiProjects that have overlapping interests.

The newsletter this month is fairly brief; not a lot of news, just checking in to say that we are hard at work and hope to have more for you soon.

Until next time,

Harej (talk) 01:44, 24 February 2016 (UTC)

”Natural units” is a misnomer for the process to remove constants from the equations.[edit]

When we measure a value of a quantity with an object O we describe an objective property of that object that does not depend on our choice of unit. So, for instance, the mass of by body is the same in London, where an old fashioned system of units is used, and in Paris, where masses are expressed with the help of the unit kg. It is an objective property of my body.

Generally, values of quantities are elements of linear spaces, and as such, they can be written as linear combinations of basis elements. When we change the basis, the coefficients of the linear combination that describes a value will change contravariantly so as to keep the value invariant. In the special case of a one-dimensional quantity, the basis has only one element and this is called a unit. Our equations that describe physical laws relate invariant values of several quantities. Consequently these equations are also invariant. No change of unit will change the aspect of the equations and especially no constants will disappear with a special use of units.

So if we use the mass value mP of a proton as the mass unit, the mass value of a proton will be 1 mass unit and not the number 1, as is stated in the article. The symbol mP will not disappear from the equations. What eliminates constant values from the equations is not a special choice of units but a change or a redefinition of quantities. So if mO is the mass value of an object O we can define a new quantity with numeric values such that the value attributed to the object O is m*O = mO/mP . This is a new quantity that describes a property of a pair of objects; <object O, proton> . But as long as we keep the second object fixed, this quantity can also be considered as a new definition of the mass. With this new definition of mass, the symbol mP will disappear from the equations. Coincidently, the reference object “proton”, which was used in order to define the new mass quantity, could also have been the object that defined the unit of the old mass quantity. But a redefinition of a quantity and a choice of unit are different things. Not always the redefinition of a quantity that eliminates constants needs a reference object. The redefinitions of quantities that make the symbols c (invariant speed) and "hbar" (Planck constant) disappear are not induced by a choice of reference objects.

I shall discus the case c = 1 as an example, because this case is an especially interesting one. Here I shall restrict my arguments to a space-time region where gravitational effects can be neglected and special relativity is sufficient to describe space-time geometry (the general case is discussed in Studies in History and Philosophy of Modern Physics 47, (2014) 107-116; http://dx.doi.org/10.1016/j.shpsb.2014.06.002).

Let A and B be two fixed points in the space of a given inertial reference frame. Imagine we install two identical atomic clocks CA and CB in these points and these clocks remain stationary at the respective points. We need two more atomic clocks of the same type, but these clocks will move in space with the kind of motion that is characteristic of free particles. The first of these traveling clocks passes through the point A and later through the point B. This clock will measure a certain traveling time τ between the events of reaching the points A and B. After the arrival of the traveling clock 1 at point B we send the second traveling clock in such a way that it passes through point B and afterwards through point A. The traveling speed of this second traveling clock shell be adjusted such that this clock will also show the same traveling time τ as the first one. Let tA1 be the time shown by clock CA when the first traveling clock passes point A. Let tB1 be the time shown by clock CB when the first traveling clock passes point B. And correspondingly, let tA2 and tB2 be the times shown by the respective stationary clocks at the respective passages of traveling clock 2. Then one can verify experimentally that:

(1) The value [(tA2 - tA1 - tB2 + tB1)2/4 - τ2]1/2 depends only on the points A and B. It does not depend on the traveling speed of the traveling clocks! If one measures this quantity for many pairs of points one may determine a function:

D(A,B) = [(tA2 - tA1 - tB2 + tB1)2/4 - τ2]1/2

(2) The function D defines a Euclidean metric in the space of the inertial frame.

(3) The ordinary distance d, which is defined with the usual measurement procedures using compasses, is proportional to D, that means the quotient d(A,B)/D(A,B) does not depend on A and B.

These observations allow us to substitute the ordinary distance d by the new function D. If one does that, other quantities such as the speed also get replaced. The new speed quantity will have values in the set of real numbers and the invariant speed c will have the value 1.

In this construction of new quantities no reference object has been used. Also the equality c = 1 has absolutely no relation to a special choice of units. You may even use your old units "second" and "meter". Ask the director of the museum in Paris for permission to measure the distance of the scratch marks on the meter bar with the atomic clock method. Probably you will get a value with considerable experimental uncertainty and the value will be something like 3.3×10-9s. Then you may call this a meter. But you may also define a meter to be 1m = 1s / 299792458. You may do with the units whatever you want; the relation c = 1 does not depend on it. So we see that “use of natural units” is an inadequate term for the procedure to eliminate certain constants from the physical equations.

The article gives the impression that scientists are cheating. The “setting a unite equal to one in parenthesis” without any explanation of the exact meaning gives this impression. We cannot simply set something equal to 1. The symbol “=” has a very definite meaning.

The term “Natural Units” is widely used in literature and even top scientists use this expression. Therefore it makes sense to have an article called “Natural Units” in Wikipedia. But the article should explain that this term is really a misnomer.

Lesche~enwiki (talk) 11:56, 25 February 2016 (UTC)

WikiProject X Newsletter • Issue 8[edit]

WikiProject X icon.svg
Newsletter • March / April 2016

This month:

Transclude article requests anywhere on Wikipedia

In the last issue of the WikiProject X Newsletter, I discussed the upcoming Wikipedia Requests system: a central database for outstanding work on Wikipedia. I am pleased to announce Wikipedia Requests is live! Its purpose is to supplement automatically generated lists, such as those from SuggestBot, Reports bot, or Wikidata. It is currently being demonstrated on WikiProject Occupational Safety and Health (which I work on as part of my NIOSH duties) and WikiProject Women scientists.

Adding a request is as simple as filling out a form. Just go to the Add form to add your request. Adding sources will help ensure that your request is fulfilled more quickly. And when a request is fulfilled, simply click "mark as complete" and it will be removed from all the lists it's on. All at the click of a button! (If anyone is concerned, all actions are logged.)

With this new service is a template to transclude these requests: {{Wikipedia Requests}}. It's simple to use: add the template to a page, specifying article=, category=, or wikiproject=, and the list will be transcluded. For example, for requests having to do with all living people, just do {{Wikipedia Requests|category=Living people}}. Use these lists on WikiProjects but also for edit-a-thons where you want a convenient list of things to do on hand. Give it a shot!

Help us build our list!

The value of Wikipedia Requests comes from being a centralized database. The long work to migrating individual lists into this combined list is slowly underway. As of writing, we have 883 open tasks logged in Wikipedia Requests. We need your help building this list.

If you know of a list of missing articles, or of outstanding tasks for existing articles, that you would like to migrate to this new system, head on over to Wikipedia:Wikipedia Requests#Transition project and help out. Doing this will help put your list in front of more eyes—more than just your own WikiProject.

An open database means new tools

WikiProject X maintains a database that associates article talk pages (and draft talk pages) with WikiProjects. This database powers many of the reports that Reports bot generates. However, until very recently, this database was not made available to others who might find its data useful. It's only common sense to open up the database and let others build tools with it.

And indeed: Citation Hunt, the game to add citations to Wikipedia, now lets you filter by WikiProject, using the data from our database.

Are you a tool developer interested in using this? Here are some details: the database resides on Tool Labs with the name s52475__wpx_p. The table that associates WikiProjects with articles and drafts is called projectindex. Pages are stored by talk page title but in the future this should change. Have fun!

On the horizon
  • The work on the CollaborationKit extension continues. The extension will initially focus on reducing template and Lua bloat on WikiProjects (especially our WPX UI demonstration projects), and will from there create custom interfaces for creating and maintaining WikiProjects.
  • The WikiCite meeting will be in Berlin in May. The goal of the meeting is to figure out how to build a bibliographic database for use on the Wikimedia projects. This fits in quite nicely with WikiProject X's work: we want to make it easier for people to find things to work on, and with a powerful, open bibliographic database, we can build recommendations for sources. This feature was requested by the Wikipedia Library back in September, and this meeting is a major next step. We look forward to seeing what comes out of this meeting.


Until next time,

Harej (talk) 01:29, 20 April 2016 (UTC)

Move angular mil to milliradian[edit]

I hereby propose to move the page Angular mil to the page milliradian. Sauer202 (talk) 12:55, 27 May 2016 (UTC)

WikiProject X Newsletter • Issue 9[edit]

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Newsletter • May / June 2016

Check out this month's issue of the WikiProject X newsletter, featuring the first screenshot of our new CollaborationKit software!

Harej (talk) 00:23, 25 June 2016 (UTC)