Talk:Wave propagation speed
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[edit] Factor of 1000
Factor of 1000 left out. Charles Matthews 18:51, 16 Oct 2004 (UTC)
Where's the maths on this page?! —Preceding unsigned comment added by 144.32.126.15 (talk) 13:51, 1 May 2008 (UTC)
- The maths for this topic is known as Telegraphers equations. Added link. --Catskineater (talk) 00:46, 22 August 2008 (UTC)
- The maths on the page were both confusing and incorrect. I have fixed the transmission line equation per Telegraphers equations and added a clarifying equation for non-transmission line situations. 12.174.19.210 (talk) 15:01, 23 February 2009 (UTC)
- Oops, I have incorrectly flipped the fraction. Reverted that equation. 12.174.19.210 (talk) 15:46, 23 February 2009 (UTC)
[edit] Merge?
From what I can gather, this is simply 1/refractive index. Should we merge to refractive index? Oli Filth(talk|contribs) 19:02, 27 May 2009 (UTC)
- No merge, please. Similarities can be seen in vacuum or in free air, but not for instance in electrical cables. Geof (talk) 13:18, 30 May 2009 (UTC)
- Why are cables a special case? They're just EM waveguides. Oli Filth(talk|contribs) 13:24, 30 May 2009 (UTC)
- Yes, but there's a lot things to be said about velocity of propagations in them. Group velocity, phase velocity, etc... What needs to be include here can be debated, but its certainly a distinct topic from refractive indices. Headbomb {ταλκκοντριβς – WP Physics} 15:55, 30 May 2009 (UTC)
- If this article had a wider scope, then I could agree with you. But as it stands, the examples you gave are already distinct articles, and not specific to EM in cables. This article isn't attempting to cover such a wide range of ideas, but simply the relationship between v and εr, and gives that relationship a name. This relationship is already implied by the first section of the Refractive index article. As such, I feel that the relationship between the two concepts would be made much clearer and compact if we merged the relatively trivial amount of content here into that article. Oli Filth(talk|contribs) 16:07, 30 May 2009 (UTC)
- I disagree. The refractive index page does not adequately cover the topic of wave propagation speed. It lists no equations and gives no "common" velocities. An explanation of (vp), or propagation velocity is required for an understanding of refractive index but they are not the same. --kf4yfd (talk) 15:24, 21 August 2009 (UTC)
- If this article had a wider scope, then I could agree with you. But as it stands, the examples you gave are already distinct articles, and not specific to EM in cables. This article isn't attempting to cover such a wide range of ideas, but simply the relationship between v and εr, and gives that relationship a name. This relationship is already implied by the first section of the Refractive index article. As such, I feel that the relationship between the two concepts would be made much clearer and compact if we merged the relatively trivial amount of content here into that article. Oli Filth(talk|contribs) 16:07, 30 May 2009 (UTC)
- Yes, but there's a lot things to be said about velocity of propagations in them. Group velocity, phase velocity, etc... What needs to be include here can be debated, but its certainly a distinct topic from refractive indices. Headbomb {ταλκκοντριβς – WP Physics} 15:55, 30 May 2009 (UTC)
- Why are cables a special case? They're just EM waveguides. Oli Filth(talk|contribs) 13:24, 30 May 2009 (UTC)
No Merge: Wave propagation speed is not equal to refractive index. Refractive index is simply the ratio of the speed of light divided by the propagation velocity (vp). Wave propagation velocity is not a very complex subject and therefore the page will never be as large as refractive index, but it is not required to be. That said, wave propagation speed could use a cleanup/rewrite.
--kf4yfd (talk) 15:24, 21 August 2009 (UTC)
Do not merge those are simply different notions, which might cross in a few formulas, not more. Materialscientist (talk) 05:38, 30 August 2009 (UTC)
- I agree that now the article title has changed, a merge may no longer be appropriate. Under its original title "Velocity of propagation" it was rather too focused on the ratio, which (AFAIK) really was refractive index under a different name. Oli Filth(talk|contribs) 10:08, 30 August 2009 (UTC)
[edit] Error in formula
It sais: where c is the speed of light, L is ... But there is no c in the formula, only C (the capacitance) —Preceding unsigned comment added by 84.197.182.66 (talk) 12:30, 2 June 2009 (UTC)
- That's because some anonymous dolt deleted the c without considering why it might be there, and no one caught it. I've reverted the change. 0x30114 (talk) 20:45, 27 August 2009 (UTC)
[edit] Ambiguity
There is some ambiguity present in the current definitions of "velocity of propagation". The first definition (1/sqrt(K)) is unitless, i.e. a fraction relative to the speed of light. The second definition (1/sqrt(LC)) is an actual velocity, in m/s. Which is correct? Oli Filth(talk|contribs) 19:12, 2 June 2009 (UTC)
- Well, the difference arose in the first place because of an inconsiderate anonymous edit, which I've reverted (see above section). But anyway, velocity factor seems like a much better term to me, although I don't know what's common among engineers. 0x30114 (talk) 20:48, 27 August 2009 (UTC)
[edit] Sources
I downloadad ARRL Handbook.pdf the 2010 --- i was unable to locate the Table in the file. The file is crappy so i was not able to search it, however chapter 19 begins on page 370, and does not contain such a table. The publication Year of ARRL Handbook and the page of the Table yould be great. ... or even other / better / free sources. —Preceding unsigned comment added by 88.215.113.163 (talk) 21:37, 8 March 2010 (UTC)
