User talk:Abmcdonald

Welcome!
Welcome to Wikipedia, Abmcdonald! I have been editing Wikipedia for quite some time. I just wanted to say hi and welcome you to Wikipedia! If you have any questions, feel free to leave me a message on or by typing helpme at the bottom of this page. I love to help new users, so don't be afraid to leave a message! I hope you like the place and decide to stay. Here are some pages that you might find helpful: I hope you enjoy editing here and being a Wikipedian! Oh yeah, I almost forgot, when you post on talk pages you should sign your name on talk pages using four tildes ( ~ ); that should automatically produce your username and the date after your post. If you need help, check out Questions, ask me on, or place helpme on your talk page and ask your question there. Again, welcome! Call me Bubba (talk) 01:58, 19 December 2008 (UTC)
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I am in a mess
I wanted to add a diagram to the feedforward page, and was under the impression that I had to place the diagram into WikiCommons. I did that but could not get the diagram appear on the feed-forward page. Then I discovered that I could load it directly into the page. So now there are two copies loaded. I then edited the diagram to remove some text and replaced the one directly linked to the feed-forward page. So the feed-forward pages is working OK.

But I am now being told I should select categories for my WikiCommons version. I can't find a list of the categories I am allowed to use, but probably the best solution would be to delete the Wikicommon version, which is now out of date, but I don't know how.

What should I do?

--A B McDonald (talk) 20:47, 23 April 2009 (UTC)


 * Hi -- so I see that there are two versions of File:Control Systems.png available: version #1 and the current version. Is that what you mean by the two versions that you uploaded?  And am I right that version #1 is the one that you described as being "out of date"? Tim Pierce (talk) 21:00, 23 April 2009 (UTC)

(edit conflict with the above)
 * Don't panic. No worries.


 * I moved this to the end; best to put new bits in a new section, at the end of your page.


 * Go to the commons version, edit it, and put db-user at the top. Sorted. Any more problems, please use another helpme at the end of this page, or talk to us live  Chzz  ►  21:03, 23 April 2009 (UTC)

Thanks, you got back to me faster than I expected. I should have said that there are three versions. A commons version which I loaded first, then version 1 which is the same as the commons version, then the current version. I am wondering if I should have loaded version 1 and then set up the commons version from it, instead of trying to do it the other way round and failing. I am worried about doing as you say in case I make the system even more confusing. A B McDonald (talk) 22:28, 23 April 2009 (UTC).


 * Don't worry about it; such things are taken care of automatically. Really, relax, it's all good.  Chzz  ►  23:12, 23 April 2009 (UTC)


 * Note to reviewers: this is part of the most recent block of 91.108.192.0/18 . It's not likely the range will be unblocked, so IPBE should be considered. --jpgordon:==( o ) 14:44, 9 September 2009 (UTC)

I have granted your account an exemption from IP blocking. This will allow you to edit through full blocks affecting your IP address when you are logged in.

Please read the page IP block exemption carefully, especially the section on IP block exemption conditions.

Note in particular that you are not permitted to use this newly-granted right to edit Wikipedia via anonymous proxies, or disruptively. If you do, or there is a serious concern of abuse, then the right may be removed by any administrator.

Appropriate usage and compliance with the policy may be checked periodically, due to the nature of block exemption, and block exemption will be removed when no longer needed (for example, when the block it is related to expires).

I hope this will enhance your editing, and allow you to edit successfully and without disruption. Daniel Case (talk) 15:09, 9 September 2009 (UTC)

Merging and automatic redirection
This suggestion is obviously well above my pay grade, but I would like to see the current fashion for merging topics not only ended but also items which have been 'lost' in mergers restored. Where the information for one topic is fully described in a second, then the fist article should be shortened to state on "See second topic" with a link. If a later editor finds that the second topic does not adequately describe the first then he can edit the first article, which is not possible at present.

Absorption coefficient has been redirected to Attenuation coefficient but they are not the same, being terms used in different sciences to describe items which have similar but not identical features. It is now impossible to explain how the Absorption coefficient is related to Einstein coefficient which has also been merged away, Grrrr.

Can anyone help me? A B McDonald (talk)


 * Nothing around here is permanent; somebody thought that merger was a good idea, he met no objections, so he did it.


 * The way Wikipedia should work is described at WP:BOLD, revert, discuss cycle - if you see a change you think would improve the encyclopedia, be bold and make it; if it is then reverted, don't re-revert but discuss and try to reach consensus. It would be possible simply to reinstate separate articles, but you should probably start a discussion and try to reach a WP:Consensus about how to do it. I see a suggestion on Talk:Attenuation coefficient about treating acoustics separately.


 * The two users mostly involved seem to be and . From their contributions, both are still around but not editing very regularly. The talk page of WP:WikiProject Physics, where others interested in this field hang out, would be a good place to look for opinions.


 * My suggestion would be: draft a proposal in a user sub-page, say User:Abmcdonald/sandbox for how you think these articles should be organised, and ask for comments at WT:WikiProject Physics and from the two users I have listed.


 * Regards, JohnCD (talk) 23:17, 17 January 2013 (UTC)7

Thanks for that advice John. My problem was not lack of boldness. It was I did not and still do not know how to un-merge two topics. is it easy? It seems to me it needs editing the merged out page but how can I get to it if I am redirected when I try to go there?A B McDonald (talk) 14:30, 2 November 2015 (UTC)
 * When you click on a redirect page and get sent to the target page, if you scroll up to the top, beneath the title at top left it will say "Redirected from (source)". Clicking on that link will take you to the source page, showing the redirect, but all the earlier version of the source page are available via the "View history" tab. JohnCD (talk) 14:55, 2 November 2015 (UTC)

Thanks again. I have now discovered that there are two pages "Absorption Coefficient" and "Absorption coefficient" differing in only the case of the first letter of the second word which have both been redirected.

The first, "Absorption Coefficient", has been redirected to "Opacity (optics)#Extinction coefficient". but the tag/patagraph "Extinction coefficient" no longer exists, although the page "Extinction coefficient" does. Moreover, the extinction coefficient and the absorption coefficient are not the same thing. The extinction coefficient is equal to the absorption coefficient plus the scattering coefficient, a bit like the attenuation coefficient!

The second, "Absorption coefficient" has been redirected to "Attenuation coefficient".

Am I correct in saying that "Absorption Coefficient" is an illegal name for an article? If so, can you (or I) delete that page, and then I will tidy up afterwards, by reinstaing the "Absorption coefficient" page and referring (not redirecting) the "Attenuation coefficient" page to it. A B McDonald (talk) 21:58, 2 November 2015 (UTC)


 * Redirects are cheap, and having one from an incorrect capitalization, like Absorption Coefficient, generally doesn't hurt. You're welcome to create a new article on the absorption coefficient if you feel there's something to be said about that topic that isn't appropriately covered in exisiting articles. (Once an article on the absorption coefficient exists, that's what "Absorption Coefficient" should redirect to, of course.) Huon (talk) 22:38, 2 November 2015 (UTC)

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On the Kirchhoff's Law of thermal radiation page: https://en.wikipedia.org/wiki/Kirchhoff's_law_of_thermal_radiation the fourth Bibliographic item is : Kangro, H. (1970/1976). Early History of Planck's Radiation Law, translated by R.E.W Madison, with the cooperation of Kangro, from the 1970 German, Taylor & Francis, London, ISBN 0-85066-063-7. When I click on the ISBN number I am taken to the Book Sources page https://en.wikipedia.org/wiki/Special:BookSources/0850660637 and the ISBN number appears in the box labelled "Search for book sources". However when I click on Search no book is found. The same thing happened when I have tried this with other ISBNs. Is this a bug with the Book Source page. A B McDonald (talk) 14:47, 2 November 2015 (UTC)
 * I don't know what is the function of that top search box, and will ask at WP:VPT where the gurus hang out. Lower down that Book Sources page, you will find links that do work, giving results from sources like Worldcat. JohnCD (talk) 15:02, 2 November 2015 (UTC)
 * I have worked out myself, without benefit of guru, the point of that top search box: if you come directly to Special:BookSources, the box is blank. When you enter an ISBN and click "Search", it populates all the other searches lower down the page. The way you came to it, that had already been done, so clicking on the top "Search" again simply repeated the process and had no visible effect. Regards, JohnCD (talk) 22:53, 2 November 2015 (UTC)
 * Thanks again John. The additional information was scrolled off my screen so I had not realised it appeared when the button was clicked :-(

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