Talk:Capillary wave

message: OK, whichever the criticism it seems clear that the derivation provided was too technical. I have followed the style of Feyman's book, and just pointed out the main assumptions made. No equations. This is probably for the better. Additional references to standard books on fluid dynamics and ocean science would be great. Best. --Daniel (talk) 09:12, 14 April 2008 (UTC)
thread_title:  New "derivation" 

message: The fact that, on average, U=T, is relevant and interesting. But I doubt this can be called "equipartition". Afak, the later refers to the fact that every degree of freedom that enter quadratically in the Hamiltonian ends up contributing (1/2) kT, in classical statistical physics. See equipartition. (This is very important for thermal capillary waves, by the way.) But I may be wrong...--Daniel (talk) 07:21, 17 April 2008 (UTC)
replies: text: Yes, it can, see Equipartition#Potential energy and harmonic oscillators. For water waves, this goes back to Rayleigh in the 19th century. Only in nonlinear water waves, this is not valid anymore. Crowsnest (talk) 16:14, 17 April 2008 (UTC)
replies: text: Still, I think this would only apply when temperature is taken into account, in the common sense of the word. Equipartition#Potential energy and harmonic oscillators says just that: a harmonic oscillator contributes a quadratic term just like a kinetic term, and therefore contributes (1/2)kT. Anyway, this is perhaps not so important since the article explicitly says that the important result is that <U>=<T>.--Daniel (talk) 07:38, 18 April 2008 (UTC)
replies: text: I removed the link to the thermal equipartition theorem, and added a reference to Rayleigh. Crowsnest (talk) 09:03, 18 April 2008 (UTC)

text: I have come across this equipartition term in an article on waves (F Behroozi, Eur. J. Phys. 25 115-122 (2004) ), so its use seems to be established. I have reintroduced the term back, but still do not dare to link to equipartition, where only the sense from statistical mechanics is discussed. I guess it is equipartition which would need some rewriting   --Daniel (talk) 13:06, 23 April 2008 (UTC)
replies: text: It is well established: linear wave systems in continuum mechanics have that the Lagrangian is zero at the critical point, so equipartition of average kinetic and potential energy (of the oscillatory motion, subtracting the "static" mean value of the potential energy). But it is different from the equipartition article for statistical mechanics. Rather than changing the equipartition article, a new article on equipartition in linear wave systems would be better, in my view. Crowsnest (talk) 18:29, 23 April 2008 (UTC)
replies: text: Indeed. Then, a disambiguation should be added at the beginning of the existing entry on equipartition.--Daniel (talk) 10:14, 24 April 2008 (UTC)
thread_title:  Equipartition? 

message: Is it really the case that the picture "Ripples on Lifjord" shows capillary waves? After all, the article states that "The wavelength of capillary waves is typically less than a few cm." So, although there is no scale on the image I have the impression that the ripples have longer wavelengths. Zebu1973 (talk) 14:46, 25 May 2011 (UTC)
replies: text: I think you are right. Perhaps it is best to remove the image from this page.--Daniel (talk) 14:32, 27 August 2011 (UTC)
thread_title:  Picture "Ripples on Lifjord"