Vis kilden til Bruker:Phidus/sandkasse-25

==Fargeblanding==
[[Fil:Sintesi additiva per proiezione di verde rosso e blu.jpg|thumb|300px|[[Additiv fargeblanding]] av [[rødt (farge)|rødt]], [[grønt]] og [[blått]] gir [[sekundærfarge]]ene [[cyan]], [[magenta (farge)|magenta]] og [[gult]].]] 

'''Fargeblanding''' eller '''fargesyntese''' kan skje på flere forskjellige måter. Ved [[additiv fargesyntese|additiv syntese]] adderes lys fra to [[lyskilde]]r og blandingen blir lysere. Derimot ved [[subtraktiv fargeblanding|subtraktiv blanding]] fjernes én eller flere [[farge]]r fra en lyskilde slik at den gir opphav til en annen [[kulør]] eller farge som da vil være mørkere. Fargen til de fleste gjenstander som omgir oss, fremkommer på denne måten.

Disse to blandinger er de viktigste. Hver av dem vil avhenge av hvilken [[fargemodell]] som benyttes. Det vil vanligvis være bestemt av hvilke [[primærfarge]]r som er valgt. For additive blandinger er disse oftest [[rødt (farge)|rødt]], [[grønt]] og [[blått]], mens for subtraktive blandinger benyttes vanligvis [[gult]] istedenfor grønt.

En tredje, mye mindre brukt  blandingsmetode er basert på gjennomsnittet av flere farger. Den fremkommer for eksempel ved å rotere en [[fargesirkel]] eller en skive med flere påmalte farger. Metoden ble benyttet allerede av [[Isaac Newton]] i hans [[Newtons fargeskive|fargeskive]] da han for første gang systematisk prøvde å forstå fargenes egenskaper basert på syv primærfarger. En tilsvarende, roterende skive ble benyttet nesten to hundre år senere av [[James Clerk Maxwell]] da han la grunnlaget for en kvantitative beskrivelse av additive fargeblandinger basert på tre primærfarger.

===Bakgrunn===

Mens [[Isaac Newton|Newton]] trodde at [[lys]] besto av små partikler, viste [[Thomas Young (forsker)|Thomas Young]] på begynnelsen av 1800-tallet at det kunne beskrives som [[bølge]]r. Han målte også [[bølgelengde]]n til hver [[farge]] i det [[Visuelt spektrum|synlige spektret]]. Ved å kombinere flere slike farger, kunne han skape nye farger. For eksempel vil gult og blått lys tilsammen gi en grønnfarge, men denne vil da ikke ha en bestemt bølgelengde. I stedet må denne blandingen beskrives ved en «spektralfordeling» som tilsvarer at dets spektrum inneholder flere bølgelengder.<ref = name>.J.C.D. Brand, ''Lines of Light'', Gordon and Breach Publishers, Luxembourg (1995). ISBN 978-28-8449-1624. [https://books.google.no/books?id=sKx0IBC22p4C&printsec=copyright&redir_esc=y#v=onepage&q&f=false Web Archive].</ref>

Undersøkelsene til Young ble vidreført av [[Hermann von Helmholtz]] og sammenfattet i en [[trikromatisk teori]] for [[Persepsjon|fargepersepsjon]]. Den er basert på antagelsen at alle fargenyanser eller [[kulør]]er kan fremkomme ved å kombinere kun tre [[primærfarge]]r som hver for seg inneholder vidt adskilte bølgeengder.  Tilsammen skal disse tre fargene gi [[hvitt]] lys. Young og Helmholtz kom frem. til at disse måtte være [[rødt (farge)|rødt]], [[grønt]] og [[blått]]. Den fysiologiske begrunnelsen for denne antagelsen var basert på at [[øye]]t ineholder tre forskjellige [[tapper]] som er spesielt følsomme for bølgelengder i disse tre områdene av det synlige spektret.

Ved å opplyse en flate samtidig med en rød (R) og en grønn (G) lampe eller lyskaster, blir den gul (Y). Likedan vil kombinasjonen av grønt og blått (B) gi en ny farge. Den blir ofte omtalt som [[cyan]] (C) elller [[turkis]]. En tilsvarende blanding av rødt og blått gir en nyanse av [[lilla]] som vanligvis kalles [[magenta (farge)|magenta]] (M). De tre primærfargene [[RGB]] gir på denne additive måten opphav til de tre [[sekundærfarge]]ne CMY som. inngår i [[CMYK|CMYK-systemet]].<ref name = Hecht> E. Hecht, Optics, Addison-Wesley, Reading, Massachusetts (1998). ISBN 0-201-30425-2.</ref>

===Formell addisjon av farger===

De tre primærfargene <math> \text{R}, </math> <math> \text{G}, </math> og <math> \text{B} </math> må være valgt slik at de til sammen gir [[hvitt]] <math> \text{W}, </math> lys. Det kan formelt uttrykes som

: <math> \text{W} = \text{R} + \text{G} + \text{B} </math>

På denne måten kan man da skrive <math> \text{Y} = \text{R} + \text{G}</math> for at rødt og grønt gir gult når de adderes sammen. Det betyr at 

: <math>  \text{Y} +  \text{B} = \text{W} </math>

To farger som til sammen gir hvitt, sies å være [[Komplementærfarge|komplementære]]. Av samme grunn er derfor cyan <math>  \text{C} =  \text{B} +  \text{G} </math> komplementær til rødt og magenta. <math>  \text{M} =  \text{B} + \text{R} </math> er komplementær til grønt.

* [[Fargeblanding]] 
* Her med addisjon a la Hecht mens komponent-addisjon spesielt på RGB

* Tysk WP, [https://de.wikipedia.org/wiki/Farbmischung Farbmischung]
* Italiensk WP, [https://it.wikipedia.org/wiki/Mescolanza_additiva Mescolanza additiva], lang og '''meget god'''
* Naturfag, [https://www.naturfag.no/forsok/vis.html?tid=2052004 ''Newtons fargespekter''], med Ormestad-Øgrim demonstrasjon fra 1986
* N.K. Rossing, [https://www.forskerfrø.no/artikkel/vis.html?tid=2129762 ''Fargede skygger og blanding av farget lys''], Forskerfrø, NTNU (2015).

==Next==
[[Fil:AdditiveColor.svg|thumb|240px|Additive colors for [[RGB]].]]
[[Fil:CMYK Color Swatches.svg|thumb|240px|Subtractive colors for [[CMYK]].]]
[[Fil:Sintesi additiva per proiezione di verde e rosso.jpg|thumb|300px|Eksempel på additive fargeblanding for [[additiv fargesyntese]].]]
[[Fil:Tartan Ribbon.jpg|thumb|240px|The first permanent color photograph, taken by Thomas Sutton in 1861 using James Clerk Maxwell's proposed method of three filters, specifically red, green, and violet-blue]]
* Engelsk WP, [https://en.wikipedia.org/wiki/Subtractive_color Subtractive color and RYB]
* [[Fargesirkel]]
* [[Goethes fargelære]], [[Ittens fargelære]]. På engelsk tilsvarer blir [[fargelære]] omtalt som [https://en.wikipedia.org/wiki/Color_theory color theory], which gives good  background
* Nynorsk WP, [https://nn.wikipedia.org/wiki/Fargesirkelen Fargesirkelen]
* Svensk WP, [https://sv.wikipedia.org/wiki/Färgcirkel Färgcirkel], inkluderer NCS-sirkel basert på 4 primærfarger. Forklart i [[Natural Color System]] 
* Engelsk WP,  [https://en.wikipedia.org/wiki/Color_wheel Color wheel], good with useful figures for illustrrations
* Ann Richmond, [https://annrichmanart.com/blog/goethes-color-theory?format=amp ''Goethe's Color Theory''], god oversikt
* Medium, [https://medium.com/hipster-color-science/a-beginners-guide-to-colorimetry-401f1830b65a Introduction to CIE Colormetry], SUPER good
* UiO Mail, [https://www.uio.no/tjenester/it/e-post-kalender/apple-mail-og-kalender/hjelp/oppsett/applemail.html Oppsett]
* NN, [http://www.compilerpress.ca/Competitiveness/Anno/Anno%20Goethe.htm Goethe Color Theory]
* SNL, [https://snl.no/farge Farge], skrevet av Torger Holtsmark som visste mye om dette
* S.K. Shevell (Ed.), [https://books.google.no/books?id=-fNJZ0xmTFIC&q=color-circle+wavelengths+newton+purple&pg=PA4&redir_esc=y#v=snippet&q=color-circle%20wavelengths%20newton%20purple&f=false ''The Science of Color''], Elsevier, Oxford (2003). ISBN 0-444-512-519. About Newton, Young, Helmholtz and Maxwell p. 28
* David Briggs, [http://www.huevaluechroma.com/062.php#historical Primary Colours], about RYB and Itten secondary colours 
* Svensk WP, [https://sv.wikipedia.org/wiki/Färgcirkel Färgcirkel]
* Italiensk WP, [https://it.wikipedia.org/wiki/La_teoria_dei_colori_(Goethe) Goethes fargelære], very good
* Nederlandsk WP, [https://nl.wikipedia.org/wiki/Kleurencirkel Fargesirkler], med interessante eksempel
* Tysk WP, [https://de.wikipedia.org/wiki/Farbkreis Farbkreis], veldig bra!
* Italiensk WP, [https://it.wikipedia.org/wiki/Spettro_visibile Spettro visibile], godt utgangspunkt med god innføring i Goethes tenkning
* Matthew Schwartz, [https://scholar.harvard.edu/files/schwartz/files/lecture7-music.pdf Music], Harvard lectures
* C.B. Boyer, ''The Rainbow: From Myth to Mathematics'', Princeton University Press, New Jersey (1987). ISBN 0-691-02405-7. 376 pp.
* SHIPS, [https://web.archive.org/web/20140929225102/http://www1.umn.edu/ships/updates/newton1.htm Newton's Colors], '''very useful'''
* J.C.D. Brand, [https://books.google.no/books?id=sKx0IBC22p4C&printsec=copyright&redir_esc=y#v=onepage&q&f=false ''Lines of Light'',] Gordon and Breach Publishers, Luxembourg (1995). ISBN 978-28-8449-1624. ([https://web.archive.org/web/20241004082507/https://books.google.com/books?id=sKx0IBC22p4C&q=light+wavelength+color++young+fresnel&pg=PA30#v=snippet&q=light%20wavelength%20color%20%20young%20fresnel&f=false Web Archive]) about Young measuring spectral wave lengths in 1802 - from observation of Newton's Rings
*  G. Waldman, [https://books.google.no/books?id=PbsoAXWbnr4C&q=Newton+color+Indigo&pg=PA193&redir_esc=y#v=snippet&q=Newton%20color%20Indigo&f=false ''Introduction to Light: The Physics of Light, Vision, and Color''], with simple adding and subtracting primary colours, pp 195. Also little history of 3-color theory, starting with Mariotte at time of Newton

[[Fil:Linear RGB color wheel.png|left|thumb|200px|Linear RGB color circle]]

===Eksterne lenker===

* David Briggs, [http://www.huevaluechroma.com/072.php#origin ''Artists Colour Wheels''], liten del av fllere websider.
* The Public Domain Review, [https://publicdomainreview.org/collection/colour-wheels-charts-and-tables-through-history/''Colour Wheels, Charts, and Tables Through History''], mange gode eksempel.
* Sarah R. Clark, [https://www.youtube.com/watch?v=yRQmV4XYmqI ''RYB vs. CMY Color Wheels''], YouTube video

* Color Wheel Artist, [https://color-wheel-artist.com/basic-color-wheel/ Basics about Color Wheels], good introduction for knit ladies

===Newtons faargeskive===
[[Fil:Newton_original_disk.svg|thumb|240px|Se mer på  [https://fr.wikipedia.org/wiki/Disque_de_Newton fransk WP].]]
* Vitensenteret, [https://vitensenteret.com/modeller/mod248.pdf ''Regnbuens farger blir til hvitt''], demonstrasjon med. Newtons skive
* Engelsk WP, [https://en.wikipedia.org/wiki/Newton_disc Newton disc], med god historie

===Color mixing===

* Youtube, [https://www.youtube.com/watch?v=ygUchcpRNyk ''Additive Color vs. Subtractive Color''], a simple but effective demonstration:. Using (110) etc coordinates. Explanation in words given by [https://www.handprint.com/HP/WCL/color5.html HandPrint]
*  The Visual Center, [https://www.youtube.com/watch?v=-b2pAEHEQZc ''Color Models Explained (Additive & Subtractive)''], Youtube video about RGB and CMYK mixing and making shadows.

===Kolorimetri===

* Nynorsk WP, [https://nn.wikipedia.org/wiki/Fargemåling Fargemåling] eller '''kolorimetri'''
* Nynorsk WP, [https://nn.wikipedia.org/wiki/Kolorimeter_for_fargeavgjersle Kolorimeter for fargebestemmelse]

==Referanser==
<references/>

{{Infoboks enhet
| navn = Candela
| enhetssystem = [[SI baseenhet]]
| enhetssymbol = cd
| oppkalt_etter = 
| enhet1 = [[Normallys]]
| innenhet1 = ≈&thinsp;{{val|1.02}} [[Normallys|cp]]&thinsp;
| enhet2 = Hefner Kerze
| innenhet2 = ≈&thinsp;{{val|1.11}} [[hefner lamp|HK]]&thinsp;
}}

==Farger==
[[Fil:Synthese+.svg|thumb|240px|Additive fargeblanding med RGB primærfarger]]
[[Fil:Farbkreis.png|left|thumb|200px|Fargesirkel med seks [[kulør]]er.]]
[[Fil:Synthese-.svg|thumb|240px|Subtraktiv fargeblanding med CMY primærfarger. Se  [https://da.wikipedia.org/wiki/Farvesystem dansk WP].]]
[[Fil:CIE-Normfarbtafel.png|right|240px|Brukt på tysk WP [https://de.wikipedia.org/wiki/Spektralfarbe Spektralfarbe].]]
* [[Farge]] er ganske bra, men kan forbedres. Har en lenke til [[fargespekter]] som ikke er lenket til andre språk og er forvirrende. Kan erstattes med [[visuelt spektrum]]. Også en side [[frekvensspekter]] som er omdirigert fra [[spektralfarge]]
* [[Fargesyn]] kan også gjøres bedre. Påstår at fargeTV basert på RYB, altså ikke RGB
* [[Kulør]] eller [[fargetone]] er det samme som engelske [https://en.wikipedia.org/wiki/Hue '''hue''']
* [[Dominerende bølgelengde]] definert i CIE-plot. Motsatt er '''komplementære bølgelengde''', relatert til [[komplementærfarge]]
* [[Grunnfarge]] er ikke lenket til andre språk og må erstattes av [[primærfarge]]
* [[Fargerom]] som er bra, men [[CIE 1931]] trenger påfyll
* HyperPhysics, [http://hyperphysics.phy-astr.gsu.edu/hbase/vision/cie.html Color space], with much more 
* HandPrint, [https://www.handprint.com/HP/WCL/color5.html Additive and Subtractive Color Mixing]
* HyperPhysics, [http://hyperphysics.phy-astr.gsu.edu/hbase/vision/addcol.html Additive color mixing]
* U. Wisconsin, [https://www.physics.wisc.edu/ingersollmuseum/exhibits/opticscolor/subcolormix/ Subtractive Color Mixing]
* CRS-group, [https://www.ccs-grp.com/guide/theory-light-color/15_color-mixing-1-additive-subtractive.html Additive and subtractive color mixing]
* NN, [https://www.rp-photonics.com/color_spaces.html Color spaces]
* T. Holtsmark SNL, [https://snl.no/farge farge] og [https://snl.no/fargelære fargelære]
* T. Holtsmark, [https://www.bokkilden.no/farger-og-fargeteori/goethes-farvelaere-johann-wolfgang-von-goethe/produkt.do?produktId=71348 ''Goethes farvelære''], Ad Notam Gyldendal, Oslo (1994). ISBN 978-82-4170-219-8. [https://www.nb.no/items/URN:NBN:no-nb_digibok_2015103006056?page=0. Nasjonalbiblioteket  online]
* Arne Valberg, [https://www.fagbokforlaget.no/Fargenes-verden/I9788251923743 ''Fargenes verden''], norsk bok
* Arne Valberg, ''Lys, Syn, Farge'', Tapir Forlag, Trondheim (1998). ISBN 82-519-1301-2. [https://www.nb.no/items/161ed8f95c81daf8d78f214a7b0a0d2a?page=0&searchText=arne%20valberg Nasjonalbiblioteket  online]. Angir p.152 that (r,g,b) koordinater i fargetrekant er '''trrilineære koordinater''', ikke barysentriske
* [[Goethes farvelære]] og [[Ittens fargelære]]
* [[Kolorimetri]] med vekt på kjemisk målinger
* [https://www.color.org/index.xalter CIE hjemmside], m/møte på Gjøvik i 2024!!!!
* Encyclopedia Britannica, ''Colours'', 11th edition (1911). [https://en.wikisource.org/wiki/1911_Encyclopædia_Britannica/Colour Online.] RGB colour triangle dates back to Thomas Young where colour of given point is given by its '''barycentric coordinates'''
* HyperPhysics, [http://hyperphysics.phy-astr.gsu.edu/hbase/vision/colspa.html#c4 Color Space], [http://hyperphysics.phy-astr.gsu.edu/hbase/vision/newtcol.html#c1 Newton Color Circle], [http://hyperphysics.phy-astr.gsu.edu/hbase/vision/addcol.html#c1 Additive] and [http://hyperphysics.phy-astr.gsu.edu/hbase/vision/subcol.html#c1 Subtractive Color Mixing] '''and much more'''
* HandPrint, [https://www.handprint.com/HP/WCL/color6.html Basics on Primary Colors], '''very detailed and excellent history'''
* A.O. Vistnes, [https://www.uio.no/studier/emner/matnat/fys/FYS2130/v09/komp12h.pdf Lys og farger], med kommentar om Goethe. Lagret i 2024
* Maxwell Foundation, [https://homepages.abdn.ac.uk/j.s.reid/pages/Maxwell/Legacy/MaxTri.html Maxwell Colour Triangle] and [https://clerkmaxwellfoundation.org/Colour_science_at_Aberdeen.pdf MORE]
* PublicDomain, [https://publicdomainreview.org/collection/colour-wheels-charts-and-tables-through-history/. Colour Wheels, Charts and Tables throughout History], lots of nice pictures!!
* Aftenposten innsikt, [https://www.aftenposteninnsikt.no/viten/fargeriket ''Fargeriket''] og psykologi (2021)
* N.K. Rossing, [https://www.naturfag.no/artikkel/vis.html?tid=2129788 Goethes fysiologiske farger], med illustrerende eksperiment med blyant... 
* SML, [https://sml.snl.no/fargesyn Fargesyn] samt [[Tapper]] og [[staver]]
* Dansk WP, [https://da.wikipedia.org/wiki/RGB-farver RGB-farver] som er god sammen med [https://da.wikipedia.org/wiki/Farvesystem farvesystem]
* R.P. Feynman, [https://www.feynmanlectures.caltech.edu/I_35.html Color Vision], Feynman Lectures, Volume I
* J.C. Maxwell, [https://www.sunyopt.edu/labs/Zaidi/CurrentProjects/Maxwell%20-%201860%20-%20On%20the%20theory%20of%20compound%20colours%20and%20the%20relations%20of%20the%20colours%20of%20the%20spectrum.pdf On the Theory of Compound Colours and the Relations of the Colours of the Spectrum], Edinburgh 1860. Stored in 2024.
* V. Roberti et al, [https://pubs.aip.org/aapt/ajp/article-abstract/90/10/787/2820286/Maxwell-s-color-box-Retracing-the-path-of-color?redirectedFrom=fulltext ''Maxwell's color box: Retracing the path of color matching experiments''], Am. J. Phys. '''90''', 787–794 (2022), '''including video'''. Extra stuff in '''Supplementary Materials''' in 2024
* V. Roberti and G. Peruzzi, [https://link.springer.com/article/10.1007/s00407-023-00317-x ''The Helmholtz legacy in color metrics: Schrödinger’s color theory''], Archive for History of Exact Sciences '''77''', 615–635 (2023) with '''Riemannian geometry.''' Stored in 2024
* MacTutor, [https://mathshistory.st-andrews.ac.uk/Projects/Johnson/chapter-5/ Maxwell and Colours]
* R. Heesen, [https://philarchive.org/archive/HEETYT Helmholtz-Maxwell and Young color dispute]
* [https://scholar.harvard.edu/schwartz/teaching Matthew Schwartz], [https://scholar.harvard.edu/files/schwartz/files/lecture17-color.pdf Lecture on Color], '''excellent''' and stored in 2024 together with similar lecture on [https://scholar.harvard.edu/files/schwartz/files/lecture7-music.pdf '''music''']
* Engelsk WP, [https://en.wikipedia.org/wiki/Young–Helmholtz_theory Young–Helmholtz theory] of colours and [https://en.wikipedia.org/wiki/Grassmann%27s_laws_(color_science) Grassmann's laws] for '''colour addition''' 
* V. Barsan and A. Merticariu, [https://www.tandfonline.com/doi/full/10.1080/23311983.2016.1145569#references-Section ''Goethe’s theory of colors between the ancient philosophy, middle ages occultism and modern science''], Cogent Arts & Humanities, '''3''', 1145569 (2016). On Goethe's opposition to Newton's theory, stored in 2024
* S.L. Jaki, [https://pubs.aip.org/aapt/ajp/article-abstract/37/2/195/1048188/Goethe-and-the-Physicists?redirectedFrom=fulltext ''Goethe and the Physicists''], Am. J. Phys. '''37''', 195–203 (1969)
* M. Treisman, [https://www.researchgate.net/profile/Michel-Treisman/publication/14181851_Why_Goethe_Rejected_Newton's_Theory_of_Light/links/557aaf3208aeacff200431a7/Why-Goethe-Rejected-Newtons-Theory-of-Light.pdf Why Goethe rejected Newton's Theory of Light], Perception '''25''', 1219-1222 (1996). Stored in 2024
* Medium, [https://medium.com/the-quantastic-journal/how-did-a-colour-scientist-come-up-with-linear-algebra-e4e1a568c4e8 Grassmann and his color triangle]
* Medium, [https://medium.com/hipster-color-science/a-beginners-guide-to-colorimetry-401f1830b65a Elementary CIE Colorimetry], '''probably the best'''
* Luminus, [https://luminusdevices.zendesk.com/hc/en-us/articles/4414846186253-What-is-the-CIE-Color-Space-What-s-the-difference-between-CIE-1931-and-CIE-1976#:~:text=The%20tristimulus%20curves%20graph%20the,of%20that%20color%20is%20strongest. CIE Collor Space] and X,Y and Z values
* Engelsk WP, [https://en.wikipedia.org/wiki/Newton_disc Newton disc], with good history leading to Maxwell wheel, i.e. [https://en.wikipedia.org/wiki/Color_wheel Color wheel]
* Engelsk WP, [https://en.wikipedia.org/wiki/Color_wheel Color wheel], with many figures and references, also [https://en.wikipedia.org/wiki/Color_triangle colour triangle]
* Engelsk WP, [https://en.wikipedia.org/wiki/RGB_color_model RGB color model] på norsk WP som [[RGB]] som bør utvides, mens [[CMYK]] er bedre
* Engelsk WP, [https://en.wikipedia.org/wiki/RYB_color_model RYB color model], with many figures and references together with [https://en.wikipedia.org/wiki/Color_space color space]
* [[Additiv fargesyntese]] eller [[RGB]] og [[subtraktiv fargesyntese]] eller [[CMYK]]
* Engelsk WP, [https://en.wikipedia.org/wiki/CIE_1931_color_space CIE 1931 color space] på norsk WP [[CIE 1931]]. Se også [https://en.wikipedia.org/wiki/LMS_color_space LMS color space] and discussion page
* Aberdeen, [https://homepages.abdn.ac.uk/j.s.reid/pages/Maxwell/Legacy/MaxTri.html Maxwell Colour Triangle]
* Engelsk WP, [https://en.wikipedia.org/wiki/Theory_of_Colours ''Theory of Colours''], summary of book content
* J.W. Goethe, [https://archive.org/details/goethestheoryco01goetgoog/page/n6/mode/2up?view=theater Theory of Colours], London (1840) sammen med [https://www.amazon.com.be/-/en/Johann-Wolfgang-von-Goethe/dp/0262570211 Theory of Colours: Introduction by Deane B. Judd], Amazon Book
* J.W. Goethe, ''Theory of Colours'', Dover Publications, New York (2006).
* Naturfag NTNU, [https://www.naturfag.no/artikkel/vis.html?tid=2129788 Goethes «fysiologiske farger» – induserte farger]
* Morten Eide, [http://www.abelie.no/PdfFiler/StrukturGoethe.pdf Strukturen i Goethes fargelære], fra Steiner-skole perspektiv. Med ''''dobbeltforhold''' matematikk. Lagt i 2024
* PublicDomain, [https://publicdomainreview.org/collection/colour-wheels-charts-and-tables-through-history/ Colour Wheels, Charts, and Tables Through History], populær
* J. Gage, [https://books.google.no/books?id=EU74cB7kMMsC&printsec=frontcover&hl=no&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false ''Color and Meaning: Art, Science, and Symbolism''], University of California Press, Berkeley (1999). ISBN 0-520-22611-9.
* Aaron Fine, [https://www.google.no/books/edition/Color_Theory/81suEAAAQBAJ?hl=en&gbpv=1&pg=PR3&printsec=frontcover ''Color Theory: A Critical Introduction''], Bloomsbury, London (2021). ISBN ....
* W. D. Wright, ''The Measurement of Colour'', '''looks like very relevant book...'''
* Print, [https://www.printmag.com/color-design/wonderful-color-wheel-part-2/ History of colour wheels], says that Maxwell got it all right and originator of todays RGB system.
* J.J. Koenderink, [https://books.google.no/books?id=VrofEAAAQBAJ&printsec=copyright&redir_esc=y#v=onepage&q&f=false ''Color for the Sciences''], MIT Press, USA  (2010). ISBN 978-0-262-01428-1. Maxwell's investigations led to Grassmann to develop his laws p.20. Grassmann's laws p.65
* S.J. Williamson and H.Z. Cummins, [https://archive.org/details/lightcolorinnatu00will/page/n5/mode/2up ''Light and Color in Nature and Art''], J. Wiley & Sons, New York (1983). ISBN 0-471-08374-7. Best recommendation from HyperPhysics and section on why '''Maxwell triangle''' must be curved

===Kulører===
[[Fil:Goethe, Farbenkreis zur Symbolisierung des menschlichen Geistes- und Seelenlebens, 1809.jpg|thumb|240px|Goethhes fargesirkel fra 1809. Mer forklarende text følger med bildet. God fremstilling på [https://it.wikipedia.org/wiki/La_teoria_dei_colori_(Goethe) italiensk WP].]]
[[Fil:Newton's colour circle.png|thumb|240px|Newtons fargesirkel fra 1730, med forbindelse til noter og planeter]]
[[Fil:Newton's color circle.png|thumb|240px|Newtons fargesirkel fra 1704 i [[Opticks]], med forbindelse til noter og ]]

===YouTube===

* [https://www.youtube.com/watch?v=YeI6Wqn4I78&t=41s Color Theory Basics], color wheels and how to use them
* [https://www.youtube.com/watch?v=k5Dh35gejuc Maxwell's Color Science - AAPT Winter 2021], Color triangle and colour box
* [https://www.youtube.com/watch?v=x7tpOkfNIHE Additive and Subtractive], elementary about color mixing
* [https://www.youtube.com/watch?v=SEJQoEQxErs Understanding How to Use the Colour Wheel]

===Maxwell works===

* Maxwell, [https://archive.org/details/scientificpapers01maxw/page/n37/mode/2up The scientific papers of James Clerk Maxwell], his '''first published paper''' at the age of 14!!! Generalising definitions of ellipse and hyperbola to ovals PLUS curves with more foci. See [https://mathshistory.st-andrews.ac.uk/Projects/Johnson/chapter-4/ MacTutor]

* William Thomson, [https://archive.org/details/transactionsofro16roy/page/540/mode/2up?view=theater Account of Carnot's Theory of Heat], January 1849. First time that word '''thermodynamics''' is used. Preceeding paper by '''Maxwell - on rolling curves''', he was then 17 years old!!

* Daniel M. Siegel, [https://books.google.no/books?id=AbQq85U8K0gC&printsec=frontcover&hl=no&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false Innovation in Maxwell's Electromagnetic Theory: Molecular Vortices ...], Google Book

* Alfred M. Bork, ''Maxwell and the development of electromagnetic theory'', Am. J. Phys. '''92''', 498–510 (2024). '''EXCELLENT history of Maxwell Eqs, rewritten by Kirrk McDonald'''. Stored in 2024 as Maxwell EM Model

==Lumen og lux==
* [[Luminans]] og [[emittans]]
* Engelsk WP, [https://en.wikipedia.org/wiki/Luminance Luminance] og [https://en.wikipedia.org/wiki/Radiance Radiance]
* [[Lys]], [[lysstyrke]] = lysintensitet og [[lysfluks]] = lysstrøm
* [[Belysningsstyrke]] er samme som [[illuminans]], og ikkje [[luminans]]
* [[Lysutbytte]] ''V''(''&lambda;'') og [https://de.wikipedia.org/wiki/V-Lambda-Kurve tysk WP] med historie
* NN, [https://www.sciencedirect.com/science/article/abs/pii/S0038092X02001196 Black body] and [https://phys.libretexts.org/Bookshelves/Astronomy__Cosmology/Supplemental_Modules_(Astronomy_and_Cosmology)/Cosmology/Astrophysics_(Richmond)/06%3A_Blackbody_Radiation HERE] 
* Fransk WP, [https://fr.wikipedia.org/wiki/Efficacité_lumineuse_spectrale#handbook2  ''V''(''&lambda;'') ]
* Youtube, [https://www.youtube.com/watch?v=Ib3sC46VV6Y La candela, une touche d’humain dans les unités de mesure]
* NIST, [https://www.nist.gov/si-redefinition/candela Candela definition]
* NIST, [https://nvlpubs.nist.gov/nistpubs/bulletin/14/nbsbulletinv14n2p255_A2b.pdf Luminous flux from black body]
* Engelsk WP, [https://en.wikipedia.org/wiki/Luminous_flux Luminous flux], tysk WP [https://de.wikipedia.org/wiki/Lichtstrom Lichtstrom] hvor omregning er gitt ved ''V''(''&lambda;'') som på norsk faller under [[lysutbytte]], som er mye bedre på [https://nn.wikipedia.org/wiki/Lysutbytte nynorsk WP] eller [https://snl.no/lysutbytte SNL]
* [https://www.mn.uio.no/ibv/tjenester/kunnskap/plantefys/leksikon/l/lysmaaling.html ''Lysmåling''],  Institutt for Biovitenskap, UiO (2011).
* SNL, [https://snl.no/lysutbytte Lysutbyttet]. og [https://de.wikipedia.org/wiki/Photometrisches_Strahlungsäquivalent Tysk WP]
* M. A. Melvin, [https://pubs.aip.org/aapt/ajp/article-abstract/23/8/508/1035438/Blackbody-Radiation-and-Lambert-s-Law?redirectedFrom=fulltext''Blackbody Radiation and Lambert's Law''], Am. J. Phys. '''23''', 508–510 (1955). Stored in 2024
* NN, [https://www.thermopedia.com/content/66/ Intensity and Emissivity from Black Body]
* [[Varmestråling]] og [[emittans]]

* Engelsk WP, [https://en.wikipedia.org/wiki/Photometria Lambert's Photometria], med detaljert history
* Tysk WP, [https://de.wikipedia.org/wiki/Lambertsches_Gesetz Lambert Gesetz]
* Engelsk WP, [https://en.wikipedia.org/wiki/Lambertian_reflectance Lambertian reflectance]

* [[Lux]] er enhet for [[belysningsstyrke]]
* [[Fargespekter]], [[frekvensspekter]], [[visuelt spektrum]] eller ganske enkelt ny side [[spektrum (fysikk)]]. Inneholder også lenke til [[grunnfarge]], men ikke til [[spektralfarge]] i motsetning til engelsk WP [https://en.wikipedia.org/wiki/Spectral_color spectral color]. [[Grunnfarge]] har ingen andre språk, men kan sannsynligvis lenkes opp mot [[primærfarge]]
* Lysstyrke er lysfluks i gitt retning, I = d\Phi/d\Omega og måles i [[candela]] = [[lumen]]/unit sr
* [[Luminans]] tilsvarer [https://nn.wikipedia.org/wiki/Radians radians] på nynorsk og omtales på dansk '''lystetthed''' ''B'', men ''L'' på engelsk. Definert som luminous flux per unit solid angle per unit projected source area. 
* AST UiO, [https://www.uio.no/studier/emner/matnat/astro/nedlagte-emner/AST1100/h09/undervisningsmateriale/lecture6.pdf Black body radiation]
* SNL, [https://snl.no/lysfluks Lysfluks] eller '''lystrøm''' er litt brukbar, Tilsvarer [[lysfluks]] '''som må gjøres mye bedre'''
* Blindeforbundet, [https://www.blindeforbundet.no/hjelpemidler-og-produkter/hva-er-lys ''Hva er lys?''], (2018).
* Engelsk WP, [https://en.wikipedia.org/wiki/Luminous_intensity Luminous intensity], measured in [[candela]]
* Engelsk WP, [https://en.wikipedia.org/wiki/Lambert%27s_cosine_law Lambert's law] '''is obeyed by radiation from surface of black body'''
* [https://nn.wikipedia.org/wiki/Hefnerlampe Hefner-lampe]
* Dansk WP, [https://da.wikipedia.org/wiki/Hefnerlys Hefnerlys]]
* NIST, [https://nvlpubs.nist.gov/nistpubs/bulletin/14/nbsbulletinv14n2p255_A2b.pdf Candela and Black Body Radiation], 1917
* [[NIST]], [https://www.nist.gov/si-redefinition/candela Candela], History and present definition (2019)
* arxiv, [https://arxiv.org/pdf/1311.3504 Candela from Planck spectrum]
* BIPM, [https://www.bipm.org/en/committees/cg/cgpm/9-1948/resolution-7 1948 Candela vedtak]]
* [[Det internasjonale byrå for mål og vekt|BIMP]], [https://www.bipm.org/documents/20126/41483022/SI-Brochure-9-EN.pdf ''The International System of Units''], definisjon av SI-enheter (2019).
* NN, [https://technology.matthey.com/content/journals/10.1595/003214086X3028495 Candela long history]
* N.R. Greene, [http://hst-archive.web.cern.ch/archiv/hst2005/part_sessions/chris/all3.pdf ''Shedding Light on the Candela''], The Physics Teacher '''41''', 409-414 (2009). Stored in 2024
* YouTube, [https://www.youtube.com/watch?v=kUwsCCBDAqU ''The Candela''], National Physics Laboratory
{{andrebetydninger2|SI-enheten Candela|den tidligere fotballspilleren|Vincent Candela}}
* [[Candela]]<ref> Gyldendals Store Konversasjonsleksikon, ''Hefnerlys'', Gyldendal Norsk Forlag, Oslo (1965).</ref>
* Svensk WP, [https://sv.wikipedia.org/wiki/Candela Candela]
* Eds. Malcolm Cooper and Jim Grozier, [https://iopscience.iop.org/book/edit/978-0-7503-1487-9/chapter/bk978-0-7503-1487-9ch0.pdf Precise Dimensions], IOP (2017). All about SI units and history - including '''candela'''

{{Infoboks Fysikalsk størrelse
| bilde = 
| bildetekst = 
| symbol = ''Φ''<sub>[[Luminosity function|v]]</sub>
| si-enhet = [[Lumen]]
| si-grunnenheter = [[Candela|cd]]⋅[[steradian|sr]]
| dimensjon = '''J'''
| avledet = 
}}

==Kilder til integrasjon==

* J.J. O'Connor and E.F. Robertson, [http://www-history.mcs.st-andrews.ac.uk/Biographies/Romberg.html ''Werner Romberg biography''], MacTutor, University of St. Andrews, Scotland.
* R.L. Burden and D.J. Faires, Numerical Analysis, Brooks/Cole, Boston (2005). ISBN 0-538-73351-9. '''Excellent''', contains also Romberg. Stored in iCloud.
* G. Hämmerlin and K-H. Hoffmann, [https://books.google.de/books?id=EZThBwAAQBAJ&pg=PA282&lpg=PA282&dq=integration+rule+simpson+kepler&source=bl&ots=aS6ns16NPF&sig=4DZ-Q1wuMkvcqujCyQ14RyDAfD0&hl=en&sa=X&ved=0ahUKEwjShK3ZlqLWAhWKPFAKHWelCOEQ6AEITjAI#v=onepage&q=integration%20rule%20simpson%20kepler&f=false ''Numerical Mathematics''], contains history which relates Kepler to Simpson-integration. Historien om Kepler mer detaljert på [https://de.wikipedia.org/wiki/Simpsonregel tysk WP].
* Atkinson, Kendall A. (1989). ''An Introduction to Numerical Analysis'' (2nd edition udg.). John Wiley & Sons. ISBN 0-471-50023-2. For numerical integration with error estimates.
* Tysk WP, [https://de.wikipedia.org/wiki/Werner_Romberg Werner Romberg], eneste Wikipedia artikkel!!!
* MacTutor, [http://www-history.mcs.st-andrews.ac.uk/Biographies/Romberg.html Romberg bio], long and detailed!!
* B. Owren, DKNV, [http://www.ntnu.no/ojs/index.php/DKNVS_skrifter/article/view/1458/1307 Werner Romberg, ''Vereinfachte numerische Integration'']
* Svare og Hemmer, [https://www.ntnu.no/c/document_library/get_file?uuid=657b9279-a301-42dd-972f-d2cbf7d6f6c5&groupId=10422 Teknisk fysikk hist - kort Romberg bio]
* Reinhard Siegmund-Schultze, [https://books.google.no/books?id=jBoEmGB3B3MC&pg=PA125&lpg=PA125&dq=werner+romberg+sweden+norway&source=bl&ots=4TqgLO-CMH&sig=I6GEGjUmtjHwYt-XLIYZ7MFZeE8&hl=en&sa=X&ved=0ahUKEwifyLzU17XVAhVCvhQKHSdoD28Q6AEIOjAD#v=onepage&q=werner%20romberg%20sweden%20norway&f=false ''Mathematicians Fleeing from Nazi Germany: Individual Fates and Global Impact''], detaljer om flukt fra Prag etc.
* Stefanie Harrecker, [https://www.utzverlag.de/assets/pdf/40691dbl.pdf Degradierte Doktoren - Die Aberkennung der Doktorwürde an der Ludwig-Maximilians-Universität München während der Zeit des Nationalsozialismus], innledning til bok? Funnet på tysk side om Romberg.
* Tore Håvie, ''Proceedings of the seminar held in honor of Werner Romberg at the University of Trondheim, Trondheim, December 8--10, 1988'', Skr. K. Nor. Vidensk. Selsk. 1989, no. 2. Tapir Akademisk Forlag, Trondheim, 1989. pp. i--viii and 1--135.
* J. Lambers, [http://www.math.usm.edu/lambers/mat460/fall09/ Lectures on Numerical Methods], '''excellent'''. Ends with FFT. Textbook used R.L. Burden and J.D. Faires, ''Numerical Analysis''.
* J. Lambers, [http://www.math.usm.edu/lambers/mat460/fall09/lecture29.pdf Romberg simply explained]
* J. Stoer and R. Bulirsch, [https://books.google.de/books?id=YJPkBwAAQBAJ&pg=PA142&lpg=PA142&dq=romberg+sequence&source=bl&ots=URdB6lCA4f&sig=n4LF4Mt338tjZ13VCaq6qQz0upA&hl=en&sa=X&ved=0ahUKEwjc9O-TwojWAhVEa1AKHRqNDa4Q6AEIVTAI#v=onepage&q=romberg%20sequence&f=false ''Introduction to Numerical Analysis''], p.141 simple example of integrating x^6 between 0 and 1.
* NN, [http://www.math.ubc.ca/~feldman/m256/richard.pdf Intro Richardson extrapolation]
* NN, [https://ub-madoc.bib.uni-mannheim.de/1674/1/130_1991.pdf History Richard extrapolation]
* NN, [http://nm.mathforcollege.com/anecdotes/romberg.html Romberg method rel. to Richardsons]
* NN, [https://www.math.vt.edu/people/qlfang/class_home/Lesson3.pdf Simplest numerical integrations]
* NN, Iowa, [http://homepage.divms.uiowa.edu/~atkinson/ftp/ENA_Materials/Overheads/sec_5-3.pdf Numerical integration], Gaussian and Romberg.
* J.H. Mathews, Fullerton, [http://mathfaculty.fullerton.edu/mathews/n2003/NumericalUndergradMod.html Numerical Integrations], all kinds of methods! Lots of examples.
* NN, [http://www.math.wsu.edu/faculty/genz/448/lessons/l5034.pdf Romberg integration] simply presented.
* NN, [http://wwwf.imperial.ac.uk/metric/metric_public/numerical_methods/integration/trapezium_simpson.html# Simplest Simpson integration]
* NN, [http://www2.math.umd.edu/~dlevy/classes/amsc466/lecture-notes/integration-chap.pdf Numerical integration with error estimate]
* NN, Iowa, [http://homepage.divms.uiowa.edu/~atkinson/ftp/ENA_Materials/Overheads/sec_5-2.pdf Errors in Trapezoidal and Simpson integration]
* NN, Pittsburgh, [http://www.math.pitt.edu/~trenchea/math1070/MATH1070_4_Numerical_integration.pdf Numerical integration] with error estimates for trapeze and Simpson.
* Young, UCSC, [http://young.physics.ucsc.edu/242/romberg.pdf '''Simpson and Romberg from trapezoidal integration'''] using Richardson extrapolation. Stored on Berliner Schreibtisch.
* Youtube, [https://www.youtube.com/watch?v=3S6CpBMcy_Y Richardson Extrapolation] used to calculate value of derivative.

===Litteratur===
* M.L. Boas, ''Mathematical Methods in the Physical Sciences'', John Wiley & Sons, New York (1983). ISBN 0-471-04409-1.
* M.J. Maron, ''Numerical Analysis: A Practical Approach'', Macmillan Publishing Company, ISBN 0-02-376210-1.

==Referanser==
<references />

==Kratzenstein sources==
* Tysk WP, [https://de.wikipedia.org/wiki/Durchschlagende_Zunge Durchschlagende Zunge], '''very good''' 
* Engelsk WP, [https://en.wikipedia.org/wiki/Christian_Gottlieb_Kratzenstein Christian Gottlieb Kratzenstein]. Tysk og dansk versjon mer fyldig.
* Engelsk WP, [https://en.wikipedia.org/wiki/Fluid_theory_of_electricity Fluid theories of electricity], w/refs to other papers at Princeton.
* Video, [https://www.awesomestories.com/asset/view/Discovering-Electricity-Lightning-in-a-Bottle Discovering Electricity by Lightning in a Bottle]
* Awesome Stories, [https://www.awesomestories.com/asset/view/Discovering-Electricity Discovering electricity], Hawskbee generator, Franklin, Leyden jar, ....
* Awesome Stories, [https://www.awesomestories.com/asset/view/Frankenstein-The-Monster-Lives0 Frankenstein and his Monster]
* M. Fowler, Virginia, [http://galileoandeinstein.physics.virginia.edu/more_stuff/E&M_Hist.html History of electricity], Franklin, Galvani, Volta, Napoleon....
* Tysk WP, [https://de.wikipedia.org/wiki/Johann_Gottlob_Krüger Johann Gottlob Krüger], Kratzensteins lærer i Halle, introduserte K til eleketroterapi og disse to ansses som elektroterapiens grunnleggere.
* H.L. Jones, [https://archive.org/stream/b21934903#page/n7/mode/2up ''Medical electricity''], H.K. Lewis, London (1904). Uten ref to K, men omtale av 2-fluid og 1-fluid theories.
* W.E. Steavenson and H.L. Jones [https://archive.org/stream/b21934915#page/n5/mode/2up ''Medical electricity''],  H.K. Lewis, London (1892).
* Tysk Wikipedia, [https://de.wikipedia.org/wiki/Durchschlagende_Zunge Durchschlagende Zunge], med beregning av frekvens. På slutten omhandler hva Kratzenstein gjorde med dette.
* Egill Snorrason, ''C.G. Kratzenstein, professor physices experimentalis Petropol. et Havn. and his studies on electricity during the eighteenth century'', Odense University Press (1974). ISBN 87-7492-092-8. På p.117 blir skrevet at så sent som i1793 fikk K enda en pris fra St. Petersburg for å ha plassert kysten av Norge 20 danske mil for langt mot øst. Dette stammer fra arbeider 1749-50 og betyr vel at dette hadde stor betydning. På p. 85 er K selv sitert at dette skyldes observasjoner på reisen i 1752.
* Kratzenstein, [http://reader.digitale-sammlungen.de/de/fs1/object/display/bsb10131365_00007.html ''Vorlesungen über die Experimentalphysik''], tysk utgave, Kopenhagen 1781.
* Kratzenstein, [https://books.google.no/books?id=X0VaAAAAcAAJ&pg=PA1&lpg=PA1&dq=kratzenstein+Theoria+electricitatis+mores+geometrica+explicata&source=bl&ots=3VqL8VTMPk&sig=i2XiAUebRN4JssM3QVQvHW8tzYs&hl=en&sa=X&ved=0ahUKEwjCz_GOlYbVAhUEAZoKHe-5Cq0Q6AEIPTAE#v=onepage&q=kratzenstein%20Theoria%20electricitatis%20mores%20geometrica%20explicata&f=false ''Theoria electricitatis mores geometrica explicata''], Halle (1746). Google Book.
* J.L. Heilbron, [https://books.google.no/books?id=UlTLRUn1sy8C&pg=PA460&dq=kratzenstein&hl=en&sa=X&ved=0ahUKEwiT2diTtMfVAhUEOpoKHdQbDx4Q6AEILDAB#v=onepage&q=kratzenstein&f=false ''Electricity in the 17th and 18th Centuries: A Study of Early Modern Physics''], 
* NN, [http://emweb.unl.edu/Mechanics-Pages/Scott-Whitney/325hweb/Beams.htm Vibrating beams], wave equation and frequencies.
* E. Jacobs, Allgemeine Deutsche Biographie, Wikisource, [https://de.wikisource.org/wiki/ADB:Kratzenstein,_Christian_Gottlieb Kratzenstein bio], skriver at født 30/1 og døpt 2/2 1723. Død 6/7 og ikke 7/7 1795.
* F. Brackhane, [http://www.coli.uni-saarland.de/groups/WB/Phonetics/contents/phonus-pdf/phonus18/phonus_18_brackhane.pdf PhD thesis]. Stored in Misc/Kratzenstein in Oslo. On p.20-22 explains free reed pipes = '''durchschlagende zunge''' som ble oppdaget/innført av Kratzenstein. On p. 22 states that Euler 1775 wrote about speech synthesiser which could function som et or gel, i.e. '''vokalorgel'''. Mer tydelig uttrykker Euler dette i 1772, gjengitt på pp. 24-25. På pp. 32-33 om Eulers tanker 1773 om språkmaskin i ''brev til prinsesse....'' På p.35 gjengis formuleringen av prisoppgaven gitt i 1779, men allerede foreslått i 1765. Euler levde til 1783. På p.46 forklares hvorfor K benyttet en durchschlagende zunge, for å unngå forstyrrelser når tungen slår mot kanten.
* F. Brackhane, [http://essv2017.coli.uni-saarland.de/pdfs/Brackhane.pdf Vokaltraktmodelle], talk given at [http://essv2017.coli.uni-saarland.de/pdfs/proceedings.pdf meeting in Saarbrücken 2017]. 
* Martin Schneider, U. Regensburg, [http://www.uni-regensburg.de/philosophie-kunst-geschichte-gesellschaft/wissenschaftsgeschichte/medien/pdf/elektrisiermaschinen.pdf ''Elektrisiermaschinen im 18. und 19. Jahrhundert, Ein kleines Lexikon''], mye om historisch elektrisitet og dens bruk. Også om Kratzenstein. Stored in Misc/Kratzenstein, Oslo.
* D.B. Fry, [https://books.google.no/books?id=Ud-8yy-DCZgC&pg=PP5&lpg=PP5&dq=fry+physics+speech&source=bl&ots=vxCeNMcag1&sig=B7pUdfKUft5M7N6-JRV-z5Gx4_w&hl=en&sa=X&ved=0ahUKEwjx7p2AkZ_VAhWrNJoKHbRyBa8Q6AEIOTAE#v=onepage&q=fry%20physics%20speech&f=false ''The Physics of Speech'']
* Hermann von Helmholtz, [https://archive.org/details/vorlesungenber03helmuoft/page/n7/mode/2up?view=theater ''Vorlesungen über die mathematischen Principien der Akustik''], Johann Ambrosius Barth, Leipzig (1898).
* Hermann von Helmholtz, [https://archive.org/stream/onsensationsofto00helmrich#page/n7/mode/2up ''On the sensations of tone...''], vocals and tones.
* Hermann von Helmholtz,  ''Die Lehre von den Tonempfindungen als physiologische Grundlage für die Theorie der Musik''. Braunschweig 1863. S. 163ff.
* Engelsk WP, [https://en.wikipedia.org/wiki/Wolfgang_von_Kempelen%27s_Speaking_Machine von Kempelen Speaking Machine]
* Engelsk WP, [https://en.wikipedia.org/wiki/Vowel Vowels] and difference with consonants.
* Engelsk WP, [https://en.wikipedia.org/wiki/Pump_organ Pump organ], på norsk [[harmonium]], explaining how '''free reeds''' are used with many links to related stuff.
* Dan Ch. Christensen, [https://books.google.no/books?id=n-sd0QQXyEkC&pg=PA174&lpg=PA174&dq=kratzenstein+oersted+copenhagen&source=bl&ots=NLAK_Lomlr&sig=vpDUtp1B-srp0X8IG720AArq3YU&hl=en&sa=X&ved=0ahUKEwjFnMbthu3UAhVnApoKHbVABn4Q6AEIMjAB#v=onepage&q=kratzenstein%20oersted%20copenhagen&f=false ''Hans Christian Ørsted: Reading Nature's Mind''], pp 120 - 170 mentiones K several times, K laid economic foundation for Ørsted's work, p.193. On p. 175 writes that K was succeeded by [[Arent Aasheim]] som professor i [[eksperimentell fysikk]]. Oxford University Press, Oxford (2013). ISBN 978-0-19-966926-4. See Amazon for first pages 1-30.
* [[Stemmegaffel]] kan bety at ''fri tunge'' kanskje skal kalles ''stemmetunge''? Artikkel om [[orgel]] omtaler [[fri tunge]].
* H. Doktorski, [http://www.ksanti.net/free-reed/history.html Free reed instruments]
* H. Doktorski, [http://www.ksanti.net/free-reed/history/birth.html Free reed instruments], history.
* U. Essen, [http://www.seam-uni-essen.de/physiologie/akustik/akustik_von_sprachlauten.htm Kratzenstein und von Kempelen], litt historie.
* U. Hessen, [http://www.seam-uni-essen.de/physiologie/akustik/resonatoren/kratzenstein04.htm Schallquellen], '''tungepipe''' eller '''leppepipe'''.
* U. Essen, [http://www.seam-uni-essen.de/physiologie/akustik/resonatoren/kratzenstein03.htm Kratzenstein resonatoren] und formanten im labor.
* U. Essen, [http://www.seam-uni-essen.de/physiologie/akustik/produktion_konsonanten.htm Produktion konsonanten], i motsetning til vokaler, kan disse ikke uttales med variabel tonehøyde (pitch), bortsett fra frikativer ( = halvvokaler).
* Christian Korpiun, U. Essen, [http://www.seam-uni-essen.de/physiologie/akustik/resonatoren/uebersicht_sprechakustik.htm Sprechakustik], med links til forskjellige vokaler og resonatorer.
* Britannica, [https://www.britannica.com/spotlight/the-mechanical-turk-ai-marvel-or-parlor-trick Wolfgang von Kempelen and the Mechanical Turk], populær fremstilling.
* Tysk WP, [https://de.wikipedia.org/wiki/Orgelpfeife#Lingualpfeifen_.28Zungenpfeifen.29 Orgelpfeifen], '''tungepipe''' eller '''leppepipe'''.
* Engelsk WP, [https://en.wikipedia.org/wiki/Reed_pipe#Free_reeds Reed pipes], eller '''tungepiper'''. Forklarer lenger ned forskjellige varianter, '''durchschlagende''' etc....
* Engelsk WP, [https://en.wikipedia.org/wiki/Speech_synthesis Speech synthesis], med omtale av Kratzenstein, von Kempelen, Wheatstone, etc.
* Norsk WP, [[Talesyntese]] som har rød lenke til [[formant]]. Kunstic eller computer-generert tale. Relatert her er sidene [[fonem]] og [[fonologi]].
* Jens Haugan, [http://www.jenshaugan.com/publications/ Publications] om norsk og nynorsk for alle! Hans gode forelesning om [[fonologi]] ligger i Dropbox.
* NN, [https://framtida.no/2016/06/19/kvifor-snakkar-skandinavar-baklengs Bestemt artikkel], fra hinn og sinn.
* Projekt Runeberg, [http://runeberg.org/cataport/0333.html Beskrivelse av Kratzenstein portrett utført av Paul Ipsen 1781], deretter kobberstikk ved [https://da.wikipedia.org/wiki/Peter_Haas Peter Haas], benyttet i Snorrason, motsatt tittelside. I Bildesamlingen, Kongelig Bibliotek, København.
* Mette Müller, [https://books.google.no/books?id=hkgoyMAdxT8C&pg=PA212&lpg=PA212&dq=kratzenstein+paul+ipsen&source=bl&ots=17TFTTcSXY&sig=auhmQKeb5vBfydK_6Dg9vv6HoK4&hl=en&sa=X&ved=0ahUKEwi4-9PxjvTUAhXFJ5oKHRz8CIwQ6AEIMjAB#v=onepage&q=kratzenstein%20paul%20ipsen&f=false ''Musikkens tjenere: instrument, forsker, musiker''], litt om Kratzenstein samt hvorfor og hvordan '''fritunger''' ble senere benyttet.
* Billedsamlingen, Det Kongelige Bibliotek, København, [https://rex.kb.dk/primo-explore/search?query=any,contains,kratzenstein&tab=default_tab&search_scope=KBB01_PRIMONY&sortby=rank&vid=NUI&lang=da_DK&offset=0 Bilder av Kratzenstein]
* Per Pippin Aspaas, [http://munin.uit.no/bitstream/handle/10037/4178/thesis/pdf?sequence=2 ''Maximilianus Hell (1720-1792) and the Eighteenth-Century Transits of Venus''], UiT, Tromsø (2012). Stored in Misc/Kratzenstein, Oslo.
* Sjuttonhundratal, [http://septentrio.uit.no/index.php/1700/article/view/2630/2482 Review av Aspaas thesis]. In Dropbox.
* Sehepunkte, [http://www.sehepunkte.de/2008/06/14300.html Rezension von: Susan Splinter - Zwischen Nützlichkeit und Nachahmung], litt negativ Kritik. Kopie i Dropbox som  Susan Splinter anmeldelse.
* Olafs Dropbox, [https://www.dropbox.com/sh/5hdzwbvumg65406/AACA7mAPFsUXwUr6h4e-ZlrIa?dl=0&preview=Kratzenstein+sjøreise.jpg Kratzensteins sjøreise]
* Olafs Dropbox, [https://www.dropbox.com/sh/5hdzwbvumg65406/AACA7mAPFsUXwUr6h4e-ZlrIa?dl=0&preview=Astronomy+Latinity+Enlightenment+Niels+Krog+Bredal+s+Poems+Commemorating+the+Transits+of+Venus+1761+and+1769.pdf Venus transits], as told by Pippin Aspaas in article about Bredal.
* Nils Voje Johansen, ''Da venuspassasjer forandret verden'', Almanakk for Norge 2012, Årgang '''199''', 81-85. Gyldendal, Oslo (2011). ISBN 978-82- 0540-9682.
* P. W. Kaplan, [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1279277/ ''The real Dr Frankenstein: Christian Gottlieb Kratzenstein?''], Jour. Roy. Soc. Med. '''95''' (11) 577-578 (2002).