Commons:Featured picture candidates/Image:Light dispersion conceptual.gif
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Image:Light dispersion conceptual.gif - not featured
[edit]- Info created by Kieff - uploaded by Kieff - nominated by SvH
- Support Phantastic!--SvonHalenbach 22:57, 20 January 2007 (UTC)
NeutralI like this way of showing light refraction and dispersion. However the size of the animated picture is too small and the light "corpuscules" of diferent wave lengths are too big. Alvesgaspar 00:19, 21 January 2007 (UTC)- Wow, I wasn't expecting this to be nominated! And I uploaded it just a few hours ago! Anyway, since this is now a FP canditate, then I guess we do need it at a larger size. It is now 450px wide (that should be enough), and the "photons" are a bit smaller too. I don't want them too small, otherwise the rainbow effect won't be very effective. — Kieff | KieffWikipedia | Talk 05:03, 21 January 2007 (UTC)
- Another suggestion: the stream of "photons" should be continuous from the begining of the animation, the feeling of motion wouldn't be lost. - Alvesgaspar 11:58, 21 January 2007 (UTC)
- Done. Purge your browser caches. I also made it 700px wide, the photons slower and even smaller. The file is actually smaller now as well, I just needed 8 frames for the animation. — Kieff | KieffWikipedia | Talk 17:06, 21 January 2007 (UTC)
- Neutral Agree with the above. Hope that it would not be too difficult to fix. What software did you use? It would be a good idea to write that down as well. Anyways, it is amazing that it was put up as an FP candidate so quickly after upload. Freedom to share 13:23, 21 January 2007 (UTC)
- Not at all, I still have the code, it's just a matter of changing the parameters :) ... I actually did this (and several other animations for Wikipedia) using mIRC. I love how it's so easy and quick to code graphics ("picture windows") on it, so I use it all the time. I won't be releasing the code, though. Can't be bothered to clean it up and write a documentation for it :P ... And I don't really see anyone being seriously interested on it anyway.... — Kieff | KieffWikipedia | Talk 17:06, 21 January 2007 (UTC)
- Support Bom trabalho, acho que está bastante melhor agora (good work, I think it is much better now). Só uma pergunta: as relações entre as velocidades de propagação associadas a cada uma das cores são as reais, ou houve algum exagero para tornar a animação mais clara ? (just one question: the ratio between the velocities of propagation of the various colours is the correct one, or was it exaggerarted to make the animation more clear?)- Alvesgaspar 18:39, 21 January 2007 (UTC)
- They were exaggerated and fine-tuned for effect, otherwise there wouldn't be a noticeable difference and the model wouldn't be as effective. — Kieff | KieffWikipedia | Talk 19:05, 21 January 2007 (UTC)
- Support - nice work! - MPF 22:44, 21 January 2007 (UTC)
- Support --Digon3 01:21, 22 January 2007 (UTC)
- Support Well done! Jnpet 18:07, 22 January 2007 (UTC)
- Support --Ziga 18:56, 22 January 2007 (UTC)
- Support -- Husky 20:52, 22 January 2007 (UTC)
- Support --Jeses 23:11, 22 January 2007 (UTC)
- Oppose I really, really like this illustration since it is very nice and clear, but I have to oppose due to physical reasons. Let me explain:
- The dots indicate that light consists of particles, which is not right. Light is electromagnetic radiation (although there is the w:Wave–particle_duality). I would like to see waves behind all the dots or even just waves.
- The dots (indicating the light) move with different speed inside the prism, but the speed of electromagnetic radiation does not depend on the frequency/wavelengths.
- I'm not a physicist, but this is my state of knowledge as electrical engineer. Probably most of wikipedia users won't recognise that, but I think that featured pictures should be absolutely correct. I will love supporting, if this is done. norro 18:13, 23 January 2007 (UTC)
- Well, that's why I called it conceptual. It's not meant to be entirely accurate, it's just a simple model to explain a certain concept. Like I've stated before, my goal was to show how different wavelengths (colors) of light behave as they travel through a medium, and how that's related to the phenomenon of refraction and dispersion. The dots serve this purpose pretty well, I think. I understand it can be misleading, but if this image is used in an article, and if it has a decent explanation on the image page (gonna work on that now), it should be enough to avoid most of that misconception. I could (and I will) make a similar version involving little waves, but I'll have to find some time for that one, since it'd be a bit more complicated. Also, light DOES slowdown when travelling through a medium, and the shorter the wavelength, the slower it will travel. The only place where light (of any wavelength) travels always at the same speed is in vacuum. Things can travel faster than light in a medium, though, and that's where Cherenkov radiation comes from. But back to the model, you can see that once the "photons" leave the prism to the black vacuum, their speeds are once again the same, so the model is correct in that aspect as well. — Kieff | KieffWikipedia | Talk 21:37, 23 January 2007 (UTC)
- Also, see the alternate image posted here. Nothing against it or anything, but I must admit, I think it conveys little information about dispersion except the fact that it happens! There are little clues in the angle of light while it is inside the prism (though it gets wrong on the exit), but you just can't expect someone to look at it and understand what's going on, especially if the person isn't already familiarized with refraction and dispersion. For all educational purposes, it's just as good as a static image. This is what I was trying to avoid. I wanted something to show, conceptually, what goes inside the prism, and for that I needed individual parts moving, so I picked dots (mainly because it was easier to understand and follow - as well as code! - but also because I thought it would work reasonably well.) It works, but it is not entirely accurate. But again, isn't that how it usually goes? We always use simplified and inaccurate scientific models in order to teach people new concepts (Newtonian physics and gravity instead of General Relativity, frictionless systems, point masses and charges, electrons as particles in orbit, etc.)... I believe that as long as we make the inaccuracy clear, we shouldn't have a problem with them. I think this applies to this image. We teach a concept, and we filter out the inaccuracies later on with a more in-depth explanation. Anyway, I'll try making a version with little waves, but I don't think complaining about inaccuracy is a valid point against the model. It's nothing a bit more of insight can't fix, and by then the model will have done its purpose, and it would have done it well enough. — Kieff | KieffWikipedia | Talk 22:54, 23 January 2007 (UTC)
- What causes the dispersion of light in the prism is precisely the fact that different wavelengths have different refraction angles, due to small differences in phase velocity. Alvesgaspar 20:03, 23 January 2007 (UTC)
- Support pink floyd forever! ;-) --AngMoKio 19:30, 23 January 2007 (UTC)
- Oppose this gives the wrong idea that the photons (big and white) are split into smaller colored photons when entering the glass surface of a prism. wrong didactic image in that sense. --Diligent 23:49, 23 January 2007 (UTC)
- Oppose If I were to judge the mere beauty: Sure, the colors are nice, the idea with the dark background is both helpful and pretty. But I'm distracted by the little "dots", similarly to Norro. It's not that this picture is inaccurate in terms of "too rough", but inaccurate in terms of "abstracting into the wrong direction": If I see light, I don't see dots. If a model shows me dots, this is novel information that should be accurate (and meaningful). Looking forward to the wave version, Ibn Battuta 05:30, 24 January 2007 (UTC)
- Oppose ack other opposers -- Lycaon 13:50, 24 January 2007 (UTC)
- Oppose I, too, am concerned about the potentially inaccurate impression that this gives a viewer who doesn't understand the underlying physics. There's too much that will tend to mislead. But I do think it's a very nice idea. --MichaelMaggs 13:10, 25 January 2007 (UTC)
- Oppose--Prolineserver 15:14, 1 February 2007 (UTC)
- Oppose Ack other opposers, especially Diligent. --Leyo 15:31, 1 February 2007 (UTC)
- Support --medium69 23:27, 1 February 2007 (UTC)
10 support, 1 neutral, 7 oppose >> not featured Alvesgaspar 19:51, 5 February 2007 (UTC)