Talk:Refraction

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This seems lacking. Where're the history and mechanism? lysdexia 13:49, 27 Oct 2004 (UTC)

Contents

[edit] Category

in what category would this article be placed in?

Well I've put it in optics. it might need to go in other categories too though. Theresa Knott (Tart, knees hot) 21:51, 14 Nov 2004 (UTC)

[edit] Image Changes

Hi, this article looked weird on a wide monitor (1920 pixels). The "See Also" section appeared to the right of the eye image, and the whole thing looked cluttered and confusing.. It wasn't clear what image the "In this diagram..." text referred to. On Safari or Firefox, it looked completely broken; the "In this diagram..." text overlapped the eye image. So, I moved the "In this diagram..." text to the image caption, and moved the image to the right. I removed the ripple tank image because it didn't seem that helpful, and there are too many images for the amount of text. Before reverting anything, please look at the old page on a wide monitor on safari or firefox... Pfalstad 8 July 2005 03:41 (UTC)

[edit] improvement

I think this article needs more technical content. 203.98.102.12 19:22, 13 January 2006 (UTC)

[edit] Question About Content

how can the wavelength increase or decrease, yet the frequency remain the same, given that frequency has an inverse relationship to wavelength?

The wave's velocity is altered at the boundary between the two media. velocity of wave = frequency * wavelength. Frequency remains the same, but wavelength and velocity are both different in the two media. Pfalstad 17:27, 23 October 2006 (UTC)
Indeed, the wavelength has to change, because light travels slower in a medium than it does in vacuum (or a sparse medium like air). One can imagine the wavefronts "bunching up" as they move into the medium where light propagates slower—the wavelength becomes shorter in the denser medium.--Srleffler 22:30, 23 October 2006 (UTC)

"The waves (water waves) travel more slowly in the shallower water." Why?

[edit] Incorrect use of the term Velocity in the first line

The first line says:

"Refraction is the change in direction of a wave due to a change in its velocity."

BUT velocity is a vector quantity, meaning it has a magnitude and a direction. Therefore, the use of velocity is incorrect. To my understanding the sentence should either:

1. "Refraction is the change in direction of a wave due to a change in its speed."

or

2. "Refraction is the change in direction component of a wave's velocity due to a change in its speed component." (or words to that effect, as that is poorly worded).

may be wrong just though I'd point it out.—The preceding unsigned comment was added by Annannienann (talk • contribs) 14:00, November 6, 2006.

It's not outright wrong, but isn't good wording.--Srleffler 20:08, 6 November 2006 (UTC)

[edit] Shouldn't wave refraction in the sea (water waves) get a look in?

we have nothing on the refraction of water waves. When I work out what it is, i'll write up on it (included in this article or seperate?)TDN 22:26, 23 November 2006 (UTC)

It's already in there. There is a paragraph on it, and two pictures.--Srleffler 05:46, 24 November 2006 (UTC)

Is it? I'll have a lookTDN 12:09, 10 December 2006 (UTC) Oh, it is. I wasn't looking carefully enough, but anyway, should there be a separate article about it? It is a different subject, coastal erosion, headlands, bays, beaches, etc. TDN 12:13, 10 December 2006 (UTC)

I'm not sure that wave refraction in water waves needs its own article. Look around carefully, you may find that there is already a lot of information on the behavior of water waves. Check out Ocean surface wave, Surface wave, and Gravity wave for various approaches to the subject. Coastal erosion may also be of interest.--Srleffler 20:08, 10 December 2006 (UTC)

[edit] Way too many vague images

At the moment, the images actually make the article appear more sporadic -- there's no real need to have the whole gamete of refraction if there's not that much expansive information. Also, the soda straw thing DOES demonstrate refraction, but it's definately a more finite example of virtual imagery. James S 19:50, 12 December 2006 (UTC)

[edit] Change in the speed of light

I got really puzzled trying to understand how could the speed of light be altered while reading this article, as I had long thought of it as the only universal measure. And took an hour thinking and searching to get the answer. Maybe linking this topic http://en.wikipedia.org/wiki/Speed_of_light#Interaction_with_transparent_materials somewhere could make it easier for people to understand it.

edit: Also, pure light would never undergo refraction or alteration of its speed? Sorry for not signing and editing this maybe not the way I should, I'm used to only reading wikipedia. thanks.

—The preceding unsigned comment was added by Japaa (talk • contribs) 23:09, 10 February 2007 (UTC).

"Pure light"? Photons, as opposed to electromagnetic waves?

The universal-measure part is only light in a total vacuum--I don't have a definite reason why light slows down in a medium (since it doesn't seem to lose energy), but...yeah. 24.16.140.208 (talk) 04:44, 15 February 2008 (UTC)

[edit] Only when it hits the boundary at an angle

Assuming that refraction is only observed when the wave changes direction (rays change velocity) why does it not mention that it is only observed when it reaches a boundary (at which a speed change is observed) at an angle? anybody? —Preceding unsigned comment added by 89.218.46.165 (talk) 14:58, 22 October 2007 (UTC)

[edit] Blue Jays/Indigo Buntings are black

Someone should add that somewhere. I don't see that anywhere! ;) --HoopoeBaijiKite 18:29, 26 June 2007 (UTC)

[edit] Momentum of a refracted ray

Apparently there is a paradox here some say could be p= nE/c (Hermann Minkowski 1908)

Or p= E/(nc) (Max Abraham 1909)

where n= refractive index, E energy of light quantum, c= speed of light in vacuo.

Rudolf Peierls raises this in his "More Surprises in Theoretical Physics" Princeton (1991). Discussed in Nature vol 444 14 December 2006 p823-824 including experiments to resolve.

It's rare for physics to fall clearly and absolutely flat on its face and a discussion of this problem by an expert should be included in the main article.--Nick Green 19:55, 9 October 2007 (UTC)

[edit] No equation?

This article needs some equations. —Ben FrantzDale 02:30, 4 November 2007 (UTC)

[edit] Geometrical Optics

Do we need a more scientific explanation of this? Saying light changes direction due to a change in speed doesn't really explain the processes involved (and is effectively incorrect as the velocity only appears to change). I'm not suggesting an in depth essay with reference to quantum electrodynamics, but the oscillating dipole model could feasibly be included. Doctorp9999 (talk) 23:12, 23 November 2007 (UTC)

[edit] Refraction effect

There is a very popular effect called Refraction, by the magician David Penn. In case someone is looking for it, I thought I should add it to the the article as a disambig link. It is a commercial effect, so I will understand if someone wishes to remove it, as potential spam. However, I understand it is the fourth best selling magic DVD in the world at the moment (though I have yet to find a valid source to confirm it). I should add that I am not benefiting from the sale of these DVDs, nor do I advertise these. I am just trying to help Wikipedia expand. StephenBuxton (talk) 18:27, 6 December 2007 (UTC)

KY3R4N —Preceding unsigned comment added by 78.149.111.200 (talk) 21:45, 27 January 2008 (UTC)

[edit] The 'Refraction in a Perspex (acrylic) block.' picture

It might be just me, but I think this picture is too vague, I can barely see what's the light source (I guess it's coming from the left side). I think we should get another picture like this (http://www.phys.ufl.edu/demo/6_Optics/A_GeometricOptics/HalfCircleRefraction.jpg sorry can't get a nice linkey) picture 131.155.108.56 (talk) 11:18, 9 May 2008 (UTC)