Talk:Curved mirror

Comments

I liked this article. It was very useful. Thai Phan 11:26, 7 March 2007 (UTC)

does anyone have any uses for convex mirrors???

Physics whizz!(not really)—The preceding unsigned comment was added by 86.131.225.86 (talk • contribs) 14:07, September 26, 2006 .

Yep. As mentioned in the article, the passenger-side mirror on a car is typically convex. Convex mirrors are also used for telescopes and lasers.--Srleffler 02:19, 27 September 2006 (UTC)

Also for the security mirrors in 24-hour stores.--Cronholm¹⁴⁴ 14:07, 2 July 2007 (UTC)

There is a question that I was hoping this page would answer that it did not. If you enlarge something greatly using a curved mirror, does the image not become darker than the original as the same quantity of photons is spread over a greater surface area? Do the colors become more muted or pale (desaturated)? — Preceding unsigned comment added by 99.48.46.142 (talk) 06:50, 24 September 2012 (UTC)

The image gets darker, as you would expect. The colors won't change unless the mirror absorbs some of the light. (Common glass is very slightly greenish, so reflections from a typical silvered glass mirror are very slightly greener than the original object. The same is true when you look through a window.)--Srleffler (talk) 17:29, 24 September 2012 (UTC)

Very useful article.....i liked it Neer kakade (talk) 15:34, 15 September 2016 (UTC)

Pictures and references

I am going to remake the pics on this article, just an FYI. Also this article needs some love in the form of a copy edit and references.--Cronholm¹⁴⁴ 14:07, 2 July 2007 (UTC)

I need help.

My dad told me to find out why a spoon gives an upsidedown reflection, I know the answer is on this page some where but I dont understand it.SzilardII 16:10, 12 July 2007 (UTC)

The spoon acts as a concave mirror, so it can actually reflect a real inverted image and a right side up non-real image, depending on the position of the reflected object. Go the the reference desk next time.--Cronholm¹⁴⁴ 22:57, 12 July 2007 (UTC)

New images

I must say that I dislike the new images. While they are pretty with their gradient-shaded mirrors, they have some flaws:

• In some of them, the mirror surfaces appear not to be spherical (i.e. the image does not show a circular cross-section).
• The radius of curvature of the reflecting surface must be twice the focal distance, centered on 2F. This does not appear to be the case in some of the figures.
• The curvature of the non-reflecting surface (and the fact that the mirrors taper to points at the ends) is bizarre. To better reflect real curved mirrors, the non-reflecting surface should either be flat, or should have the same radius of curvature as the reflecting surface (with center of curvature offset by the thickness of the mirror).
• The reflecting surface should be clearly distinguished from the non-reflecting surface in each figure. This could be accomplished by a bolder line on that surface. Having flat non-reflecting surfaces would probably be sufficient for the context of this article.

--Srleffler 04:26, 8 September 2007 (UTC)

I am sorry you dislike them, I followed in the form of what was there before. I can remake them again, but I am rather busy with real life right now. If you would like to change them yourself using inkscape, that would be really helpful. I will try to finish the new ones tomorrow, but if not, I won't be able to work again until next weekend. Cheers—Cronholm¹⁴⁴ 08:53, 9 September 2007 (UTC)

Lens

Can you make a new section about concave and convex lens, please? because the rules differ with them i think... and i want to know if i've got the concepts right. KdN+91 (talk) 00:58, 15 November 2008 (UTC)

Try Lens (optics).--Srleffler (talk) 09:33, 15 November 2008 (UTC)

Spherical reflector

Spherical reflector redirects to this article (Curved mirror). This is incorrect since not all spherical reflectors are mirrors (for example the Arecibo Radio Telescope[1]). Spherical reflectors, both mirror and non-mirror, have specific applications[2][3]. The redirect should be taken down and that article expanded. This would be a counterpart article to Parabolic reflector. Fountains of Bryn Mawr (talk) 22:38, 22 November 2008 (UTC)

It depends on what your definition of mirror is. A reflector for radio waves could certainly be considered to be a type of mirror. Either way, I disagree with taking out the redirect. Mirrors are by far the dominant application. If a separate article is needed, we could add a dablink to the top of this article, pointing to the other article. It's not clear to me that a separate article is needed though.--Srleffler (talk) 02:46, 23 November 2008 (UTC)

Merge request

Could a contributor to this article (who is more knowledgeable in this subject matter than I) please check out Gaussian formula and merge any relevant content into this one, then redirect it appropriately? Thanks, Hermione1980 23:29, 7 December 2008 (UTC)

Done. There was little to merge. The formula is already here, and the derivation of the formula violates WP:NOTTEXTBOOK. All that was really missing was the fact that the formula is attributable to Gauss. --Srleffler (talk) 06:08, 8 December 2008 (UTC)

Field of view

I need help. I am looking for a formula to calculate Field of View of a convex mirror with known focal length/radius of curvature. —Preceding unsigned comment added by Yogdeepdesai (talk • contribs) 07:09, 28 January 2009 (UTC)

It's probably the same as for a lens of the same focal length. See Angle of view.--Srleffler (talk) 19:09, 28 January 2009 (UTC)

Hohlspiegel

Es wird ab Mai 2009 drei Spiegel geben mit 3,5 Meter Durchmesser mit 2,4 Meter Durchmesser mit 1,5 Meter Durchmesser.

Ehrlich, mir ist nicht klar wo da ein Unterschied sein soll, bei den Beobachtungergebnissen vielleicht machen sie jeweils je 1 Bild von der Sonne und je ein Bild von allen Planeten und kleine Planeten (Pluto Erdmond), wobei Beobachtungsbilder in scharz weiss entstehen (Die Farbfotos macht nur der Computer) . Mich interessiert auch wie genau die derzeitigen Positionen der Planeten sind, insbesonders ob die Planeten um die Sonne in konzentrischen Kreisen um die Sonne sich bewegen (habe da so meine Zweifel, der Mond und der Jupiter Saturn auf einer Konzentrischen Kreis um die Sonne?).

Nehmen Sie mal an, sie wuerden jedes dieser 3 Weltraumteleskope an den Uhrzeitpunkten 3 Uhr 6 Uhr 9 Uhr um die Sonne platzieren, dann haetten sie im Ruecken der Weltraumteleskope die Elektromagnetische Strahlung der Sonne immer . Wenn sie nun davon ausgehen, das sich diese Elektromagnetische Stralung der Sonne im Sonnensystem kugelfoermig ausbreitet , haben sie in 1.000.000 Kilometer von der Sonne entfernt eine kleinere kugelfoermige Beobachtungsform als in 10.000.000.000 km oder gar 1.000.000.000.000.000 km. Wie wollen sie unter diesen Vorraussetzungen einen Punkt mit den 3 Weltraumteleskopen (Beispiel Sonne ist moeglich --Stern--) den sie als Uruniversum oder Urknall bezeichnen finden, wissen sie denn wo sich dieser befindet? Hinter der Sonne in 30 Grad Nord in 100.000.000.000 km?

http://de.wikipedia.org/wiki/Hohlspiegel

Gehen Sie mal in das IMAX Kino am Potsdamer Platz (Potsdamer Platzakarden), dieses Kino besteht aus einer ausserlich Sichtbaren grossen Kugelform (in meiner Vorstellung sieht so mein Universum Urknall Weltraum Weltform Kosmos aus). Wobei nicht klar ist ob diese Kugelform einen Durchmesser von 1.000.000.000.000.000.000.000.000.000.000.000.000.000 Kilometer(Rechengrundlage ist die Lichtgeschwindigkeit und die Ausbreitungsform des Lichtes -- kugelfoermig--) hat.

@Super- Mario "- hier gehts nicht um unser Sonnensystem sondern ums gesamte Universum - das ist der Teil des Alls, der noch weit hinter der Sonne liegt -"

Nun stellen sie sich in die Kugelfoermige Mitte des IMAX Kugelbaus und nehmen ein Kugelfoermiges Licht (Sonne) in einer Groesse mit einem Kugeldurchmesser von 1 Zentimeter, um diese 1 Zentimeter grosse Kugelsonne lassen sie ein kugelfoermige Erde mit einer Groesse von 1 Millimeter Bahnen um die Miniaturkugelsonne kreisen (Durchmesser dieses Kreises 300.000.000 Kilometer). Beim Sonnensystem (alle Himmelskoerper im Sonnensystem) sind sie schon in einer berechneten Entfernung von 15.000.000.000 Kilometer bis 20.000.000.000 Kilometer, wenn sie nun das Licht der Sonne zugrunde legen, die seit 4.570.000.000 Jahren (Erdumlaufbahnen um die Sonne, warum nicht die des Marses) scheint, kommen sie auf einen Sonnenlichtradius mit einem Kreisdurchmesser (Scheibe in einer Kugelform) von bis zu 10 hoch 43 Kilometer.

Die Sonne ist immer am gleichen Ort.

• http://www.welt.de/wissenschaft/weltraum/article3702138/Superteleskope-sollen-Mysterien-des-Alls-lueften.html?page=1#article_readcomments
• http://www.welt.de/wissenschaft/weltraum/article3716292/Riskante-Reparaturarbeiten-am-Hubble-Teleskop.html 87.194.122.68 (talk) 12:50, 11 May 2009 (UTC)

This is the English Wikipedia. You will find that you get more response to your message if you post it at Diskussion:Hohlspiegel, on the German Wikipedia.--Srleffler (talk) 22:31, 11 May 2009 (UTC)

Parabolic or spherical more common?

I do realize spherical mirrors are very common in telescopes, but mirror telescopes aren't everyday objects yet. I suppose shaving mirrors and automotive mirrors would be spherical too, but again not sure about how many of those there are in the world. Most people own quite a few flashlights though, and those all have parabolic mirrors. Does anyone have any hard data on how many car mirrors that are spherical there are, as compared to flashlights with parabolic reflectors? -- User:Cimon Avaro

Images

I noticed that people have been expressing their dissatisfaction with the images in the article, mainly because of the size, shape and curvature of the mirrors illustrated. I did a little digging on Commons and found the following images for convex mirrors, which look okay:

• Convex mirrors
• 
  File:Concavo 1.png
• 
  File:Concavo 1.svg
• 
  File:Concavo 2.png
• 
  File:Concavo 2.svg
• 
  File:Concavo 3 simplificado.svg
• 
  File:Concavo 3.png
• 
  File:Concavo 3.svg
• 
  File:Concavo 4.png
• 
  File:Concavo 4.svg

If I can find corresponding ones for convex mirrors and no one objects, I'll replace the ones in the article with these. --- — Preceding signed comment added by Cymru.lass (talk • contribs) 23:27, 6 March 2011 (UTC)

These look good. The svg versions are better than the png ones.--Srleffler (talk) 05:25, 7 March 2011 (UTC)

Parmigianino's self portrait

I think it might be relevant to show the image of self portrait of Parmigianino http://en.wikipedia.org/wiki/Self-portrait_in_a_Convex_Mirror — Preceding unsigned comment added by 195.50.169.234 (talk) 12:03, 2 September 2014 (UTC)

Help me!

Please help the Simple English Wikipedia. I am desperate for a page on this.Qwertyxp2000 (talk) 05:13, 21 November 2014 (UTC)

concave mirror

The difference position of source of light with respect to concave mirror in torches???????? Neer kakade (talk) 15:37, 15 September 2016 (UTC)

Ideally, a torch that uses an incandescent light bulb would have a parabolic reflector, with the filament of the bulb located at the focus of the reflector. If the light source were a point source located at the focus, the reflector would produce a perfect collimated beam. Since the filament is not a point source, the beam has some angular spread.--Srleffler (talk) 00:48, 16 September 2016 (UTC)

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