Talk:Transparency and translucency/Archive 1

Question
What properties of materials makes them transparent? —Preceding unsigned comment added by 82.33.131.54 (talk) 10:47, January 16, 2005
 * That depends on the structure of the electrons of the outer shells of the substance and in particular, how these electrons interact in the solid body being the material. There is a complicated theory "predicting" (calculating) absorption and its spectral dependence of different materials. —Preceding unsigned comment added by 145.64.134.241 (talk) 11:03, September 7, 2005

Induced transparency
Article should also discuss Induced Transparency, Electromagnetically Induced Transparency and transparent metals (aluminium can be made transparent). —Preceding unsigned comment added by Vinsci (talk • contribs) 18:36, March 17, 2005

Difference between transparency and translucency
May I sugest the following difference between TRANSPARENT an TRANSLUCENT:

A transparent body lets more or less light go through, BUT does not affect the information transmitted (imagine for example the dark glasses used to observe a  solar eclipse).

A translucent body, on the other hand, prevents the information to get through: there is light going through, but one can not distinguish what is on the other side.

—Preceding unsigned comment added by 82.155.116.184 (talk) 19:35, November 3, 2005

done
Induced Transparency, Electromagnetically Induced Transparency and transparent metals (aluminium can be made transparent). Are on the AMB page under Engineering. Mion 15:20, 22 January 2006 (UTC)

Still needs
There is a complicated theory "predicting" (calculating) absorption and its spectral dependence of different materials. Mion 15:20, 22 January 2006 (UTC)


 * I'd like to see more of a discussion of this. That is, what are the physics of transparency; what's happening with light waves/photons that allows them to pass through a transparent material. A brief discussion of other EM wavelengths would be nice too; i.e., noting how (for example) brick walls are transparent to longer radio waves, though not to microwaves. RedSpruce 13:54, 24 September 2007 (UTC)

done
Mion 15:27, 22 January 2006 (UTC)

Solids
What is the most transparent solid? Plexiglass lets more light through than glass, but it's still possible to see light reflecting off of it. Is there a solid that lets so much light through that it's almost impossible to tell that it's there?

general quality of discussion low
This page doesn't have a very cogent discussion of the physical processes (scattering and absorption) involved in making a material "transparent", "translucent", or "opaque"...52.128.30.23 20:09, 25 May 2007 (UTC)Jim

Pyrex not a plastic?
The phrase, "most glasses, and plastics such as Perspex and Pyrex" implies that both Pespex and Pyrex are plastic. Pyrex isn't a plastic. 140.147.160.34 (talk) 22:21, 2 January 2008 (UTC)Stephen Kosciesza

A Question from Children
Children have asked me, but I've never been able to answer: "How come light passes through glass which is hard and dense, and not through cardboard which is softer and less dense?" They want to know if in glass there are "tunnels" through the glass that let photons slip through unobstructed, or if its more like a chain reaction where a photon entering the glass bumps off another photon which bumps off another photon, etc., until a photon emerges out the other side. Can someone please answer this in a way that, let's say, a twelve-year-old, could understand? Skeppy (talk) —Preceding undated comment was added at 08:42, 8 October 2008 (UTC).

Skeppy:

This is basically a particle size effect.

When a ray of light strikes the surface of an opaque object, it is typically scattered in any nmuber of directions, especially if the surface possesses roughness or irregularities. We refer to this type of reflection as “diffuse reflection”, and is typically characterized by wide variety of reflection angles.

Most of the objects that you see with the naked eye are visible due to diffuse reflection. Another term commonly used for this type of reflection is “light scattering”. Light scattering from the surfaces of objects is our primary mechanism of physical observation.

But all light travels in waves -- and light scattering depends on the wavelength of the light being scattered. Visible lightwaves have a range of wavelengths from 0.3 to 0.8 microns (one millionth of a meter!). Thus, scattering centers (or particles) as small as one micron have been observed directly in the light microscope (e.g. Brownian motion of colloidal particles). But anything smaller than that will not be "seen" (or actually scattered) by the lightwave. It will just continue on past the object as though it did not even exist!

The carboard you refer to is composed primarily of wood pulp fibers which are MUCH larger than that. In fact, there is a close-up photo of paper which is actually used to describe the process of diffuse scattering on the following website:

http://sol.sci.uop.edu/~jfalward/physics17/chapter12/chapter12.html

Alternatively, the scattering centers in a typical glass are molecules, which are much smaller than the wavelength of visible light. Thus, most glasses are transparent to visible lightwaves.

Colloidal particles are right on the cusp. Therefore the new tranparent ceramic materials being produced are processed from nanoscale (from "nanometer", one billionth of a meter !) particles which are even smaller than colloids. This is why we call it "nanotechnology".

I hope this helps :-)

~ Professor Bob ~

logger9 (talk) 05:45, 21 January 2009 (UTC)

Merge with Transparent materials proposal
Since January this article has been tagged with a merger proposal template, suggesting to merge Transparency (optics) into Transparent materials. However, there does not seem to have been much discussion on the subject. I feel that this page should me merged, as the current page is of poor quality (too short, no refs) and repeats information found in the transparent materials article. Logger9 seems to agree with me, from out discussion on Talk:Transparent materials. What do other editors think? —fudoreaper (talk) 20:32, 8 June 2009 (UTC)
 * An update. In order to complete the merger, we just need to replace Transparency (optics) with a redirect to transparent materials.  The merger is essentially complete, without any objections, i may redirect this page on my own in the next few days.  Please comment. —fudoreaper (talk) 23:45, 10 June 2009 (UTC)
 * NOTICE: after 10 days with no objections, no comments at all, I am getting close to converting this page into a redirect. I will wait another few days, and then act.  —fudoreaper (talk) 01:44, 21 June 2009 (UTC)


 * No objections here. I already tried it once! Good luck with it :-) -- logger9 (talk) 06:47, 25 June 2009 (UTC)
 * It is done. I have converted Transparency (optics) into a redirect to Transparent materials.  Comments are still welcome, but please explain why you think a revert is appropriate if you disagree with Logger9 and I. —fudoreaper (talk) 19:38, 26 June 2009 (UTC)