Editing Diffraction grating (section)

===Natural gratings===
[[File:Iridescent biofilm on a fishtank.JPG|thumb|A [[biofilm]] on the surface of a fishtank produces diffraction grating effects when the bacteria are all evenly sized and spaced. Such phenomena are an example of [[Quetelet rings]].]]
[[Striated muscle]] is the most commonly found natural diffraction grating<ref>{{cite journal|last1=Baskin |title=Light diffraction study of single skeletal muscle fibers|pmc=1328609 |pmid=318066|doi=10.1016/S0006-3495(79)85158-9|volume=28|issue=1|date=October 1979|journal=Biophys. J.|pages=45–64|bibcode = 1979BpJ....28...45B |first1=R.J.|last2=Roos|first2=K.P.|last3=Yeh|first3=Y.}}</ref> and, this has helped physiologists in determining the structure of such muscle. Aside from this, the chemical structure of crystals can be thought of as diffraction gratings for types of electromagnetic radiation other than visible light, this is the basis for techniques such as [[X-ray crystallography]].

Most commonly confused with diffraction gratings are the [[iridescent]] colors of [[peacock]] feathers, [[mother-of-pearl]], and [[butterfly]] wings. Iridescence in birds,<ref name="stavenga">{{Cite journal | doi = 10.1016/j.matpr.2014.09.007| title = Thin Film and Multilayer Optics Cause Structural Colors of Many Insects and Birds| journal = Materials Today: Proceedings| volume = 1| pages = 109–121| year = 2014| last1 = Stavenga | first1 = D. G. | doi-access = free}}</ref> fish<ref>{{Cite journal | doi = 10.1073/pnas.1216282109| title = High levels of reflectivity and pointillist structural color in fish, cephalopods, and beetles| journal = Proceedings of the National Academy of Sciences| volume = 109| issue = 50| pages = E3387| year = 2012| last1 = Roberts | first1 = N. W.| last2 = Marshall | first2 = N. J.| last3 = Cronin | first3 = T. W.|bibcode = 2012PNAS..109E3387R | pmid=23132935 | pmc=3528518| doi-access = free}}</ref> and insects<ref name="stavenga"/><ref>{{Cite journal | doi = 10.1242/jeb.098673| title = Coloration principles of nymphaline butterflies - thin films, melanin, ommochromes and wing scale stacking| journal = Journal of Experimental Biology| volume = 217| issue = 12| pages = 2171–2180| year = 2014| last1 = Stavenga | first1 = D. G.| last2 = Leertouwer | first2 = H. L.| last3 = Wilts | first3 = B. D. | pmid=24675561| doi-access = free}}</ref> is often caused by [[thin-film interference]] rather than a diffraction grating. Diffraction produces the entire spectrum of colors as the viewing angle changes, whereas thin-film interference usually produces a much narrower range. The surfaces of flowers can also create a diffraction, but the cell structures in plants are usually too irregular to produce the fine slit geometry necessary for a diffraction grating.<ref>{{Cite journal | doi = 10.1111/nph.12808| pmid = 24713039| title = Iridescent flowers? Contribution of surface structures to optical signaling| url=https://www.researchgate.net/publication/261515138 | format=PDF| journal = New Phytologist| volume = 203| issue = 2| pages = 667–73| year = 2014| last1 = Van Der Kooi | first1 = C. J. | last2 = Wilts | first2 = B. D. | last3 = Leertouwer | first3 = H. L. | last4 = Staal | first4 = M. | last5 = Elzenga | first5 = J. T. M. | last6 = Stavenga | first6 = D. G. | doi-access = free | bibcode = 2014NewPh.203..667V}}</ref> The iridescence signal of flowers is thus only appreciable very locally and hence not visible to man and flower visiting insects.<ref>{{cite book |first=David W. |last=Lee |title=Nature's Palette: The Science of Plant Color |url=https://books.google.com/books?id=M3e5wyFJY-8C&pg=PA255 |date=2007 |publisher=University of Chicago Press |isbn=978-0-226-47105-1 |pages=255–6 }}</ref><ref>{{Cite journal | doi = 10.1111/nph.13066| pmid = 25243861| title = Is floral iridescence a biologically relevant cue in plant-pollinator signaling?| url=https://www.researchgate.net/publication/265912479| format = PDF| journal = New Phytologist| volume = 205| issue = 1| pages = 18–20| year = 2015| last1 = Van Der Kooi | first1 = C. J. | last2 = Dyer | first2 = A. G. | last3 = Stavenga | first3 = D. G. | doi-access = free| bibcode = 2015NewPh.205...18V}}</ref> However, natural gratings do occur in some invertebrate animals, like the [[Maratus|peacock spiders]],<ref>{{Cite journal|last1=Hsiung|first1=Bor-Kai|last2=Siddique|first2=Radwanul Hasan|last3=Stavenga|first3=Doekele G.|last4=Otto|first4=Jürgen C.|last5=Allen|first5=Michael C.|last6=Liu|first6=Ying|last7=Lu|first7=Yong-Feng|last8=Deheyn|first8=Dimitri D.|last9=Shawkey|first9=Matthew D.|date=22 December 2017|title=Rainbow peacock spiders inspire miniature super-iridescent optics|journal=Nature Communications|language=En|volume=8|issue=1|pages=2278|doi=10.1038/s41467-017-02451-x|pmid=29273708|pmc=5741626|issn=2041-1723|bibcode=2017NatCo...8.2278H}}</ref> the antennae of [[seed shrimp]], and have even been discovered in [[Burgess Shale type fauna|Burgess Shale fossils]].<ref>{{harvnb|Lee|2007|p=41}}</ref><ref>{{cite web |title=Colouring in the fossil past |date=15 March 2006 |work=News |publisher=Natural History Museum |url=http://www.nhm.ac.uk/about-us/news/2006/mar/news_7834.html |access-date=14 September 2010 |archive-url=https://web.archive.org/web/20100812044454/http://www.nhm.ac.uk/about-us/news/2006/mar/news_7834.html |archive-date=12 August 2010 |url-status=dead }}</ref>
 
Diffraction grating effects are sometimes seen in [[meteorology]]. [[Corona (optical phenomenon)|Diffraction coronas]] are colorful rings surrounding a source of light, such as the sun. These are usually observed much closer to the light source than [[halo (optical phenomenon)|halos]], and are caused by very fine particles, like water droplets, ice crystals, or smoke particles in a hazy sky. When the particles are all nearly the same size they diffract the incoming light at very specific angles. The exact angle depends on the size of the particles. Diffraction coronas are commonly observed around light sources, like candle flames or street lights, in the fog. [[Cloud iridescence]] is caused by diffraction, occurring along coronal rings when the particles in the clouds are all uniform in size.<ref>{{cite book |first=G. P. |last=Können |title=Polarized Light in Nature |url=https://archive.org/details/trent_0116300226960 |url-access=registration |year=1985 |publisher=Cambridge University Press |isbn=978-0-521-25862-3 |pages=[https://archive.org/details/trent_0116300226960/page/72 72]–73}}</ref>