User talk:AxelBoldt

Please add new comments at the bottom. I will reply on this page. If I wrote something on your talk page, please reply there. The idea is to make quoting easy and keep conversations in their logical order.

Older talk can be found in User_talk:AxelBoldt/Archive.

Dear Axel,

I think your revisions of the hyperventilation article have improved it generally. Thank you. I do have one reservation though. I would like to somehow restore the information that breathing is the primary pH regulation mechanism both because it gives some perspective on how hyperventilation can get pH out of whack, and because this important fact is not easy to find. What do you think?

--AJim 01:26, 2 Jan 2005 (UTC)

Oh yes certainly, I didn't really mean to cut that. Please restore. (Perhaps one could also mention this function of breathing in the respiration article.) Maybe you have also something to say regarding my question on Talk:Hyperventilation. Cheers, AxelBoldt 18:57, 3 Jan 2005 (UTC)

Contents

1 Barnstar 2 Santorum 3 Gyrocompass 4 New Mathematics Wikiportal 5 |Closeup of a house fly 6 hydrogen chloride and hydrochloric acid 7 Mathematics Project Participants List 8 fictitious force 9 small groups 10 Retina article - perception of red blood cells 11 IfD 12 Antibody 13 Ladder paradox

Barnstar

Hello Axel. I don't know what you think about the barnstars that are often awarded for outstanding contributions to Wikipedia, but I have taken the liberty of placing one on your user page after being amazed that there weren't a whole string of them there already. Feel free to move it to a more convenient location, change the caption, or remove it altogether as you wish. And keep up the good work! — Trilobite (Talk) 03:13, 7 Jan 2005 (UTC)

Thanks a lot, I'm flattered! AxelBoldt 06:54, 7 Jan 2005 (UTC)

Santorum

You deleted useful information about the neologism usage, replacing it with a wikilink to a nonexistent article. Are you creating or planning to create such an article? If not, the Santorum page should go back to its previous state. JamesMLane 06:56, 24 Jan 2005 (UTC)

I agree that the information was useful, but it was a duplication of the material at Savage Love. Since duplication is bad and disambiguation pages aren't supposed to contain much information anyway, I directed the reader to that article. Then I realized that an article santorum (word) already exists which currently redirects to Savage Love. So pointing to santorum (word) seemed the most logical: if we ever decide to take the material out of Savage Love and place it in its own article (which I'm currently not planning to do), then the disambiguation page at santorum will still point to the right place. Cheers, AxelBoldt 07:10, 24 Jan 2005 (UTC)

I don't think duplication is bad if it makes the information more accessible to the reader. (If it creates too much clutter, of course, then duplication makes the information less accessible.) In this instance, I think the setup that's most useful to readers is that someone who enters "Santorum" in the search box gets a listing of the different meanings and can find elaboration on either without getting bogged down in the Savage Love stuff, which may well be irrelevant to this reader. That could be done with a separate article at Santorum (word), but, like you, I'm not planning to create it. It's borderline whether it merits a separate article. Absent such an article, I think giving the information in the dab page is the way to go.

Meanwhile, I see that someone else reverted, unaware of the discussion here. I guess I should have put my comment on the article talk page instead of here, but I thought you might be doing a separate article, so I wanted to be sure you saw my question. JamesMLane 17:20, 24 Jan 2005 (UTC)

I continued on Talk:Santorum. AxelBoldt 19:19, 24 Jan 2005 (UTC)

Gyrocompass

Hi Axel,

I came across your article on the gyrocompass.
I'm curious: do you agree that the physics involved in how a gyrocompass works corroborates a hardly known aspect of general relativity? Many books on general relativity, especially books that popularize science, claim that all acceleration is as relative as the relativity between inertial velocities. If that would be true, the gyrocompass would violate general relativity. So a proper interpretation of general relativity must contain that angular velocity can be measured locally, without reference to other local matter.
An observer can measure an anisotropy in the Cosmic Background Radiation, presumebly that is the closest he can come to measuring his velocity with respect to the part of the universe visible to him. But it appears to me that a gyrocompass measures its own rotation with respect to the universe by comparing itself with local space-time.
I noticed the link to Reflections on Relativity, at mathpages.com, that's where I get most of my information on relativity. Cleon Teunissen 19:27, 27 Jan 2005 (UTC)

Yes, it appears to me that one can locally determine angular velocity with a gyroscope, and I don't think that contradicts any statements of general relativity (except maybe the simplified accounts you mention). However, I shouldn't be trusted on any of this; it has been too long that I studied GR. Cheers, AxelBoldt 18:47, 29 Jan 2005 (UTC)

Ah, you know, I think this is very ironical. I get the impression that some people take personal pride the idea that they have absorbed the highly counter-intuitive idea that all reference frames are indistinguishable, including rotating reference frames. Lately I have been involved in discussions with someone about these matters, and I wonder whether he may decide to take the stance that gyroscopes contradict general relativity. Cheers, Cleon Teunissen 19:49, 29 Jan 2005 (UTC)

New Mathematics Wikiportal

I noticed you've done some work on Mathematics articles. I wanted to point out to you the new Mathematics Wikiportal- more specifically, to the Mathematics Collaboration of the Week page. I'm looking for any math-related stubs or non-existant articles that you would like to see on Wikipedia. Additionally, I wondered if you'd be willing to help out on some of the Collaboration of the Week pages.

I encourage you to vote on the current Collaboration of the Week, because I'm very interested in which articles you think need to be written or added to, and because I understand that I cannot do the enormous amount of work required on some of the Math stubs alone. I'm asking for your help, and also your critiques on the way the portal is set up.

Please direct all comments to my user-talk page, the Math Wikiportal talk page, or the Math Collaboration of the Week talk page. Thanks a lot for your support! ral315 02:54, Feb 11, 2005 (UTC)

|Closeup of a house fly

Hi. The Image was on the commons, and got deleted because Stock.xchng images are not 100% free. I have uploaded it again to the english wiki. -- Chris 73 Talk 00:10, Feb 19, 2005 (UTC)

hydrogen chloride and hydrochloric acid

Hi, Axel,

you were the original one to create the [[hydrogen chloride] wikipage, to distinct it from hydrochloric acid, which is chemically correct. As the major product, the hydrochloric acid page has been up for review for some time, and now the question is asked whether it is optimal to re-combine the two or not. Would you please be so kind as to add to the discussion? Wim van Dorst 17:18, 2005 Mar 13 (UTC)

Mathematics Project Participants List

Hi Axel. After some discussion here, I've converted the "WikiProject Mathematics Participants List" into a table. It is now alphabetical, includes links to the participant's talk page and contribution list, and has a field for "Areas of Interest". I'm letting you know, so you can update your entry, if you want.

Paul August ☎ 22:41, Mar 18, 2005 (UTC)

fictitious force

Hi Axel,

I'd like an outside opinion on my article on fictitious force. Reading through early versions of the article and conversations on talk pages, I saw that a lot of people are struggling to make sense of it. I was a struggle for me too. My current article on fictitious force is rather long, and very detailed. I did that on purpose, knowing how confused many people are about it; I strive to dispell all confusion.

Can you please check out the article, and tell me whether you feel I have reached my objective? --Cleon Teunissen | Talk 13:44, 19 Mar 2005 (UTC)

Hi, I don't really know enough about physics to meaningfully evaluate the article, but nevertheless here are a couple of random observations:

• you need a link to force
• in the intro paragraph, you mention "the force he can measure" yet it is not clear which force that is or why he can measure it
• in the next section, the crucial role of the observer is never mentioned again
• in the car example, it's not clear which is the ficticious force: the one pressing from the seat towards my back, or the opposite one of my back pressing into the seat. This should be clearly related with the definition in the intro paragraph
• it's not explained in which direction the centripetal force acts
• both the sections on linear and circular acceleration have a couple of concluding sentences that are of a general nature and don't belong in those sections
• the general relativity section is not intelligible. At one point, it talks about a frame that's fixed relative to "the stars". The stars of our galaxy (which rotate around the galaxy's center), or those of distant galaxies? The repeated anthropomorphization with "know" is out of place.

Cheers, AxelBoldt 00:45, 20 Mar 2005 (UTC)

Thanks, I'll try and see what I can do about it. The general relativity section is only intelligable to people who are thoroughly familiar with general relativity. The only purpose of the general relativity section is to show that it is unnecessary to invoke general relativity. Earlier versions of the fictitious force article claimed erroneously that General Relativity proves that centrifugal force is just as much a force as gravity.
About the expression: relative to "the stars". I'm a physicist. To me, the rotation of our galaxy is negligably small compared to rotations that matter in daily life, so to me 'distant stars' is unambiguous. To a mathematician 'the distant stars' leaves room for ambiguity. --Cleon Teunissen | Talk 08:50, 21 Mar 2005 (UTC)

• in the next section, the crucial role of the observer is never mentioned again AxelBoldt 00:45, 20 Mar 2005 (UTC)

Well, in terms of physics, there is no role for the observer at all. The physics remains the same, independent of the perspective (and the physics understanding) of the observer.
The only role the observer can play is in his own mind, the observer may confuse himself. So I don't mention the observer in the case of linear acceleration, as people are usually not confused about that. The section on linear acceleration is meant as preparation for the next section. I aim to address the self-confusion in the case of circular motion, so in that section there is more focus on the observers mind.
Thanks again for your recommendations, I tried to work them into the article. --Cleon Teunissen | Talk 09:40, 21 Mar 2005 (UTC)

Hi

http://en.wikipedia.org/wiki/Wikipedia%3AVillage_pump_%28miscellaneous%29#Retrospective

Anthere 06:01, 21 Mar 2005 (UTC)

small groups

Hi - I wanted to construct a cycle diagram for one of the order 12 groups listed in the "list of small groups" article. Its the one with the following description:

the semidirect product of C3 and C4, where C4 acts on C3 by inversion

Can you give me a product table for this group? Thanks - PAR 15:52, 29 Mar 2005 (UTC)

I'd rather not write down the whole table with its 144 entries, but you should be able to construct it from the following information: take as elements the pairs (x,y) with x in {0,1,2} and y in {0,1,2,3} and define the group operation * by

(x₁,y₁) * (x₂,y₂) = ((x₁+ φ(y₁)x₂) mod 3, (y₁+y_{2) mod 4)}

where φ(y) is defined to be +1 if y is even and -1 if y is odd. The neutral element is (0,0). Cheers, AxelBoldt 23:54, 29 Mar 2005 (UTC)

Good, that worked - Thanks PAR 01:50, 30 Mar 2005 (UTC)

Hi again- I wanted to construct cycle graphs for all 16-element groups, but I don't have an exhaustive list or their product tables. I can figure out the ones that are composed of lower order groups, but I will have a hard time with the others. Do you have a least a list of all 16-element groups, and at best, an algorithm or table for the difficult ones? Thanks - PAR 23:17, 30 Mar 2005 (UTC)

I don't have a list -- most lists in text books stop at 15, since there are so many groups of order 16. I believe the software GAP includes a complete list though, and it can produce product tables, but I don't know the details of how to do it. AxelBoldt 00:46, 31 Mar 2005 (UTC)

Retina article - perception of red blood cells

Would you happen to have a citation handy regarding the cause of tiny moving dots in the field of vision? See my question at Talk:Retina. Thanks - mjb 08:44, 30 Mar 2005 (UTC)

IfD

Hi Axel,

Just to let you know that I have nominated for deletion the image Image:Death of Marat.jpg that you uploaded. It seems to have largely been obsoleted by Image:Death of Marat by David.jpg now. -- Solipsist 20:23, 23 Apr 2005 (UTC)

Thanks for letting me know! I'm not opposed to the deletion, but when comparing the two images I just noticed that they differ substantially in their color and in the inscriptions on the wood block and on the paper. Interesting! Cheers, AxelBoldt 18:44, 24 Apr 2005 (UTC)

Antibody

Are you sure antibodies are not glycoproteins? JFW | T@lk 08:03, 22 Jun 2005 (UTC)

Oops, you are right, they are. I'm reverting. Thanks, AxelBoldt 17:52, 22 Jun 2005 (UTC)

Ladder paradox

I noticed you contributed to the twin paradox in special relativity. I wonder if you would comment on the arguements going on on the ladder paradox page. We could really use your help. PAR 05:16, 23 Jun 2005 (UTC)