Discussione:Movimenti della Terra

Movimenti della Terra
Argomento di scuola secondaria di II grado
Materia	scienze della Terra
Dettagli
Dimensione della voce	4 244 byte
Progetto Wikipedia e scuola italiana

Domanda

Mi chiedevo se non si stia parlando della stessa cosa quando si citano nell'articolo la precessione luni-solare e la nutazione. Non sono la stessa cosa? --62.110.229.174 07:49, 16 mar 2007 (CET)

removed image

Pardon my english, I don't write Italian. This image, while quite beautiful, originally gave a completely wrong explanation for this phenomenon. As an example, it implied that the precession caused by the Sun on the Earth is constant throughout the year, when in fact it varies according to the sine of the Earth's orbital position. The misleading parts have been clumsily removed, but it is not very nice anymore. There is more discussion here. Please do not re-add this image. 216.239.45.4 (msg) 18:32, 14 set 2010 (CEST)

It is not balck or white, mathematically what you wrote could be correct, but for such simple illustrative image there is no differences and this is understandable from the discussion you indicated. Plus this italian voice is not focused on "Axial precession", but in a most general issue of earth movements. In other word: I am agree that 10/3 is not equal to 3.3, but at some approssimation 3.3 could be fine. Obvioulsy any costructive improvement is welcome, as a new image for instance.--Bramfab Discorriamo 19:30, 14 set 2010 (CEST)

Ah - thanks; I think a more fundamental problem here is that this image is being used to show the "I principali moti della Terra", when that is not what is in the image. That is, most of the arrows in the image are not "I principali moti della Terra" as defined in the article. 67.218.106.225 (msg) 19:06, 15 set 2010 (CEST)

The arrows are showing "movimenti" and forces acting on. Quite understandable by anyone having basic notions of physics and astonomy --Bramfab Discorriamo 19:10, 15 set 2010 (CEST)

But many of the arrows are not the movements described in the article. That is simply not the point of the image. Huh, I guess that is one way to settle an edit dispute that you are involved in. 67.218.106.225 (msg) 19:20, 15 set 2010 (CEST)

Please use File:Rotating_earth_(large).gif or a different image instead. I'm trying to delete the other one, since it is quite misleading to anyone who stumbles across it trying to figure out exactly how axial precession really works, and I can not delete it if you are using it. Thank you, 208.54.5.55 (msg) 19:33, 15 set 2010 (CEST)

By the way please settle your discussion on Commons, and the image in this page will folloow its fate. The gif you propose shows only the rotation of earth around its axis, this page is dealing about the combinations of more then 5 earth movements ! By the way I put a note to the astronomy project. --Bramfab Discorriamo 21:57, 15 set 2010 (CEST)

Commons generally will not delete images that are in use elsewhere in the project. 208.54.5.67 (msg) 22:24, 15 set 2010 (CEST)

And just to reiterate, the image shows many arrows that are "not" any of those 5+ movements, so it is very confusing in the context of this article. 208.54.5.67 (msg) 22:32, 15 set 2010 (CEST)

Every-day there are images used in it.wikipedia and deleted from Commons! Please continue your personal batte against this image in Commons, it seems that you want to delete here just to have a vantage in your discussion there. Otherwise please be able to explain correctly why this image is false and more convincing than propose a simple rotating earth image in lieu of a complex image. Somebody from Progetto:Astronomia will read by sure and give adivise or act directly in case.--Bramfab Discorriamo 22:36, 15 set 2010 (CEST)

"it seems that you want to delete here just to have a vantage in your discussion there" - Please assume good faith. I want to delete it here (and everywhere) because it is a misleading, and therefore harmful, diagram. I have explained why it is false above, and linked to here where consensus clearly concurs. I have tried to explain why it is unhelpful and confusing here in this article, I'll elaborate by pointing out that the orange, blue, and green arrows are not movements, and will confuse anyone who thinks they are relevant to this article. The point of the diagram is to explain why the axis precesses, not to demonstrate various movements of the Earth. It just doesn't work here. 208.54.5.57 (msg) 23:05, 15 set 2010 (CEST)

• Misleading ?:
  • red circle: moto di rivoluzione (approssimato in quanto sarebbe una ellisse, ma accettabile)
    • Right - the red one is fine, that isn't one of the ones I mentioned. 216.239.45.4 (msg) 19:10, 16 set 2010 (CEST)
  • blu circle: moto di rotazione
    • Nope, that blue donut is supposed to represent the equatorial bulge. It isn't even an arrow, so no. 216.239.45.4 (msg) 19:10, 16 set 2010 (CEST)
  • orange circle: Variazione dell'inclinazione dell'asse terrestre
    • No - The axis don't vary that way. See? It caused confusion. 216.239.45.4 (msg) 19:10, 16 set 2010 (CEST)
  • white & yellow circle: approssimazione grafica per rendere Precessione degli equinozi e Precessione anomalistica.
    • Yup, again, these ones aren't the problem, just the orange arrow, the blue(cyan) arrows, and green arrows(the earth doesn't move toward the sun!). And now that you mention it the blue circle is confusing too, since it is totally superfluous to this article. 216.239.45.4 (msg) 19:10, 16 set 2010 (CEST)

Ending this note: another admin had repeat to you what I wrote you above: let Progetto:Astronomia to analise the usefullness of this image for this page and see if their comments match the comments you received on Commons. --Bramfab Discorriamo 09:27, 16 set 2010 (CEST)

Ok, I look forward to their input, thanks for putting a note on that project (that's a good way to resolve a dispute, Bramfab - ask for outside assistance; thanks.) But I'll just note that the dispute here is not really the same as the dispute on commons. thanks,216.239.45.4 (msg) 19:10, 16 set 2010 (CEST)

"Periodo di tempo impreciso":

Cito il paragrafo "Moto di rivoluzione" dalla pagina per cui avvio questa discussione:

"Moto di rivoluzione: è il movimento della Terra attorno al Sole secondo un’orbita ellittica e dura 365 giorni, 5 ore, 48 minuti e 46 secondi e a causa di questo periodo di tempo impreciso ogni 4 anni è presente un anno bisestile per ristabilire quell'asse di tempo che ci indica che a giugno e a luglio farà caldo e che a dicembre e gennaio farà freddo. Determina anche il cambiamento delle stagioni causato anche dall'inclinazione dell'asse terrestre."

Ritengo che definire "impreciso" il periodo di tempo che la Terra impiega per compiere una rivoluzione completa sia fondamentalmente scorretto. Impreciso rispetto a cosa? Possiamo piuttosto dire che tale lasso di tempo non è conforme alle unità di misura del tempo convenzionali adottate dall'umanità.

Il paragrafo dovrebbe essere riformulato utilizzando un linguaggio più corretto.