Wikipedia:Featured picture candidates/Composite light wave dispersion

Composite light wave dispersion[edit]

Voting period is over. Please don't add any new votes. Voting period ends on 11 Nov 2010 at 22:09:06 (UTC)

Reason: High EV as evident in articles. Properly demonstrates several phenomena of physics using a ubiquitous image. Technically, it is free of defects, has an appropriate resolution (though an animated SVG would be the optimal format), is simply styled and loops at a comprehensible pace.
Articles in which this image appears: Prism (optics), Optics, Electromagnetic radiation, Transparency and translucency, Spectroscopy
FP category for this image: Wikipedia:Featured_pictures/Sciences/Others under Animations (or Wikipedia:Featured_pictures/Diagrams,_drawings,_and_maps/Diagrams may also be suitable)
Creator: Lucas V. Barbosa (Kieff)

Support as nominator --nakomaru (talk) 22:09, 2 November 2010 (UTC)[reply]
Support Hypnotising! Aaadddaaammm (talk) 07:00, 3 November 2010 (UTC)[reply]
- Withdraw my support until we clear up if it's physically accurate. Aaadddaaammm (talk) 07:27, 4 November 2010 (UTC)[reply]
  - OK I trust you ;) Support Aaadddaaammm (talk) 12:45, 7 November 2010 (UTC)[reply]
Support surprisingly informative. Nergaal (talk) 07:59, 3 November 2010 (UTC)[reply]
Support as above. J Milburn (talk) 11:11, 3 November 2010 (UTC)[reply]
Oppose White light isn't split into seven different wavelengths but every colour of the rainbow. Straight lines would better reveal the different angles due to the varying refractive indicies with wavelength. I much prefer something like File:Dispersive Prism Illustration by Spigget.jpg. Noodle snacks (talk) 01:42, 4 November 2010 (UTC)[reply]

That image is wrong, because inside the prism the light is not diffracted yet (still white). I said that this image is surprisingly informative specifically because the wavelengths are graphically depicted, which GREATLY aids a non-expert understand why is the light actually diffracting that way. I just love that the animation CLEARLY shows that different wavelengths have different speeds inside the medium (which is actually the origin for the prism effect). The animation File:Light dispersion conceptual.gif shows lines, and might be more clear; but I do believe that the nominated animation is just great. Nergaal (talk) 05:11, 4 November 2010 (UTC)[reply]

Noodle snacks, if I understand correctly you have two issues regarding its characterization of the phenomena.

First, that the true physics of white visible light is not a composition of merely 7 discrete wavelengths, but a continuous spectrum. This is true (until we begin to talk about quantization). However, I believe that it is not misleading for two reasons: a) the caption explicitly states this, and b) it is also explicitly stated (and implicit) that this is a schematic - a tool used to comprehend the underlying principles. Discretization of the continuous spectrum into several components, be it seven or however many, is the very thing that allows us to meaningfully compare the different speeds, directions and wavelengths. The imagery that everyone knows is simple and beautiful, and is suitable for an introduction picture, but it doesn't teach us about why it is happening, just that it is happening.

Second, that straight lines would better reveal the angle differences. I agree, but then we wouldn't see the speed change. I believe the discussion moves to comparing the particle version with the wave version by the same author.

Both the speed and angle differences in the particle version is very obvious, whereas in this version it is obvious but slightly less so.

It is very clear that the wave version is used more in articles. I believe the particle version was used previously and replaced with the wave version two years ago. The editors seem to think the wave version has higher EV.

The particle version loses the comparison between wavelengths. In fact, the wavelength is the principle characteristic of light which causes the speed change in different media which causes the angle change which causes dispersion. The wavelengths are more important than the color in this picture.

The wave version gives a strong impression that the components are -bending- as they change media.

The wave version illustrates the in-phase and out-of-phase quality of white light. As you stare at the first incident, the wave peaks will converge and diverge. The particle version loses this hypnotizing effect, and its loop time is much quicker as a result.

As Nergaal states, the illustration that you posted is physically inaccurate because it doesn't show the dispersion happening within the prism. To Aaadddaaammm: I believe this schematic to be physically accurate and correctly representing what it says it is. I don't believe its accuracy was called in to question, just the method it uses to characterize the phenomena. nakomaru (talk) 09:06, 4 November 2010 (UTC)[reply]

NS: Any further thoughts? Nergaal (talk) 09:01, 9 November 2010 (UTC)[reply]

You can think the white beam is 7 superposed lasers. Grinatyou (talk) 12:44, 9 November 2010 (UTC)[reply]

Oppose ack. Noodle snacks. --Alchemist-hp (talk) 08:55, 5 November 2010 (UTC)[reply]

Please understand that the caption has always explained the difference between the reality and the schematic. "The white beam represents many wavelengths of visible light, of which 7 are shown, as they travel through a vacuum with equal speeds c." There is absolutely nothing inaccurate about this schematic that anyone has mentioned. nakomaru (talk) 01:22, 7 November 2010 (UTC)[reply]

I'm no physicist. Consider my support withdrawn until people are happy that this is accurate. J Milburn (talk) 13:06, 5 November 2010 (UTC)[reply]

Not Promoted --Makeemlighter (talk) 00:54, 12 November 2010 (UTC)[reply]