Talk:Gegenschein

Physics of light[edit]

As a physicist, I question the statement exlaining the gegenschein: "(b) the backscattering geometry leads to constructive interference." A randomly positioned set of dust particles won't cause constructive interference of backscattered light. -Spirko 20:53, 23 March 2006 (UTC)[reply]

I agree. My understanding of physics suggests that Gegenschein is more aptly described as an interplanetary analog of the 'solar glory' http://en.wikipedia.org/wiki/Glory_(optical_phenomenon) or an anthelion http://en.wikipedia.org/wiki/Anthelion . --tadchem 10:09, 24 October 2008 (EDT) 131.81.200.92 (talk) 14:11, 24 October 2008 (UTC)[reply]

Actually, if the particle density depends on the distance to the sun (or to earth), then a randomly positioned set of dust particles can cause cunstructive interference. —Quilbert (talk) 17:32, 30 October 2008 (UTC) … theoretically, but considering the wavelengths, this is nonsense; you are right. —Quilbert (talk) 17:40, 30 October 2008 (UTC)[reply]

"The intensity of gegenschein is (relatively) enhanced because each dust particle is seen in full phase."

That would give a very broad patch of light (50% of peak intensity at 90 degrees) - this is narrower. Dust is generally retro-reflective because the particles, seen from the light source, do not cast their shadows on each other. You can sometimes see the effect in uniform fields of grass or cereal crops. Heiligenschein is the dew equivalent, Opposition effect in dry conditions.

--87.194.174.252 (talk) 12:41, 23 September 2009 (UTC)[reply]

If we agree, please remove the similar sentence from Zodiacal light, too ! --87.194.174.252 (talk) 13:39, 23 September 2009 (UTC)[reply]

counterglow on the net[edit]

Exactly what relevance does the link to the counterglow website have to do with this entry. It seems to be a webportal. Rozzychan 05:06, 3 August 2006 (UTC)[reply]

Its actually a forum (follow the link to community) but feel free to remove the link if you wish. --Spartaz 21:40, 3 August 2006 (UTC)[reply]

German pronunciation[edit]

It's pronounced gay-geyn-shine. —Preceding unsigned comment added by Beowulf1978 (talk • contribs) 04:45, 3 November 2007 (UTC)[reply]

As a German I can assure you that the German pronounciation is ˈgeːgənʃaɪn, not ˈgeɪgənʃaɪn (provided that I have found the correct symbol from the special characters list). As far as I know there is no English equivalent to the german eː. However, I do not know whether there is a convention about a more "anglified" pronounciation in English.--SiriusB (talk) 08:50, 7 May 2008 (UTC)[reply]

Categories[edit]

"Atmospheric optical phenomena" is incorrect since this occurs in interplanetary space outside the atmosphere. 69.72.27.25 (talk) 19:13, 17 November 2012 (UTC)[reply]

Second figure, caption issue[edit]

Although the caption provided comes from the description in Wikimedia Commons provided by the original photographer Yuri Beletsky, I believe there is an error. The "band running diagonally from top left to lower right" is the zodiacal light, whereas the gegenschein is the enhancement of the zodiacal light at 180 degrees from the sun. In the photo, this occurs at the center in the left/right direction, along the band (vertically above the silhouetted flat-roofed building).

I would suggest a change from the current caption "The Gegenschein is seen in this image as a band running diagonally from the top left to lower right." to perhaps "The Gegenschein is seen as an enhanced brightness in the band of zodiacal light running from top left to lower right, directly above the silhouetted flat-roofed building."

I am reticent to make the edit myself owing to the original description coming from the actual photographer, but I do believe it is wrong.

Here is a different photo of the full excursion of the zodiacal light with the gegenschein noted at the 180 degree location.

--Gscreol (talk) 02:36, 18 May 2013 (UTC)Gscreol[reply]

Gegenschein vs Gegen licht[edit]

Please see pictures if you google Gegen licht. It's means you see light behind the object, but this light is not from that it is a reflection. I think gegen is a wrong word for that. --Beyond silence 10:22, 26 February 2017 (UTC)[reply]

Not sure what you are looking for here. The word licht does not appear in this article. The German term Gegenlicht means backlit; see de:Gegenlicht. Gegen means against, among other things. Eric ^talk 13:59, 26 February 2017 (UTC)[reply]

incomplete[edit]

isn't there a period when gegenschein is no longer visible? Where's the info on that? 100.15.117.34 (talk) 19:05, 24 March 2023 (UTC)[reply]