User talk:Rmo13

Thanks for the article on Jerzy Petersburski. I was about to write it myself... Halibutt 13:28, 10 February 2006 (UTC)


 * Hi there! I replied to your questions at Talk:Rzeczpospolita. BTW, you might want to sign your posts next time you make a comment at the talk page. To do this just write four tildes at the end ( ~ ) and the wiki will convert that to your name and exact date. Halibutt 18:06, 22 February 2006 (UTC)

Tide
Dear Rmo13, At Tide, you added:
 * Atmospheric tides are the dominant dynmics from about 80 km to 120 km where the molecular density is too small, and are both gravitational and thermal in origin.

Hmm? Too small for what? -- JEBrown87544 15:51, 21 March 2007 (UTC)

Earth radius; oblique curvature
Hiya Rmo13! Nice addition to Earth radius! P=) I particularly like your touching on the rhumb/Pythagorean relationship to radius of curvature——though there does need to be a distinction made between spherical ("globoidal") azimuth, denoting here as $$\widehat{\alpha}\,\!$$, and the (local) elliptical/geodetic azimuth, $$\tilde{\alpha}(\phi)\,\!$$:


 * $$R_c=\frac{{}_{1}}{\frac{\cos(\tilde{\alpha}(\phi))^2}{M}+\frac{\sin(\tilde{\alpha}(\phi))^2}{N}}=\frac{(M\cos(\widehat{\alpha}))^2+(N\sin(\widehat{\alpha}))^2}{M\cos(\widehat{\alpha})^2+N\sin(\widehat{\alpha})^2},\,\!$$

as $$\tilde{\alpha}(\phi) =\arctan\left(\frac{N(\phi)\sin(\widehat{\alpha})}{M(\phi)\cos(\widehat{\alpha})}\right) =\arctan\left(\frac{N}{M}\tan(\widehat{\alpha})\right).\,\!$$

In your relating $$D\cos\widehat{\alpha}\approx Md\phi\,\!$$ and $$D\sin\widehat{\alpha}\approx N\cos\phi d\lambda\,\!$$, you miss a more profound relationship:


 * $$\begin{align}D&\approx\sqrt{(Md\phi)^2+(N\cos(\phi)d\lambda)^2},\\

&=\sqrt{(M\cos(\widehat{\alpha}))^2+(N\sin(\widehat{\alpha}))^2}\sqrt{(d\phi)^2+(\cos(\phi)d\lambda)^2},\\ &=\frac{\sqrt{(d\phi)^2+(\cos(\phi)d\lambda)^2}}{\sqrt{(\frac{\cos(\tilde{\alpha}(\phi))}{M})^2+(\frac{\sin(\tilde{\alpha}(\phi))}{N}})^2},\\ &=\widehat{\overline{O}}(\widehat{\alpha},\phi)\sqrt{(d\phi)^2+(\cos(\phi)d\lambda)^2},\\ &=\tilde{\overline{O}}(\tilde{\alpha}(\phi),\phi)\sqrt{(d\phi)^2+(\cos(\phi)d\lambda)^2};\end{align};\,\!$$

Thus,


 * $$\begin{align}R_o=O&=\widehat{\overline{O}}(\widehat{\alpha},\phi)=\tilde{\overline{O}}(\tilde{\alpha}(\phi),\phi),\\

&=\sqrt{(M\cos(\widehat{\alpha}))^2+(N\sin(\widehat{\alpha}))^2} =\frac{1}{\sqrt{(\frac{\cos(\tilde{\alpha}(\phi))}{M})^2+(\frac{\sin(\tilde{\alpha}(\phi))}{N}})^2};\end{align}\,\!$$

With those relationships in mind, would O be considered the "oblique radius of curvature" (i.e., radius of plane curve arc, or "radius of arc", or "arcradius"), and the curvature, itself, "oblique curvature" (i.e., plane curve arc), as north-south curvature is "meridional curvature" and east-west curvature is "normal curvature", with their respective radii, M and N? ~Kaimbridge ~19:40, 28 March 2007 (UTC)

Water: To do list
I see that you were the editor who added the 'scope' or 'purpose' to the to do list. I can't find any discussion of this however. Is it just something you added without discussion, or did I miss it? Richard001 08:12, 1 August 2007 (UTC)

RE: References
Hola! Aren't references, like in List of North American ports suppose to be EXTERNAL?

I could create an article, then put in rubbish, then go to other articles and cite that article....

Citing sources and also Citing sources/example style

207.69.139.139 21:00, 18 September 2007 (UTC)

ArbCom elections are now open!
MediaWiki message delivery (talk) 13:03, 23 November 2015 (UTC)

File:Tide type.gif listed for discussion
A file that you uploaded or altered, File:Tide type.gif, has been listed at Files for discussion. Please see the to see why it has been listed (you may have to search for the title of the image to find its entry). Feel free to add your opinion on the matter below the nomination. Thank you. Magog the Ogre (t • c) 00:22, 28 January 2017 (UTC)