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Discover the fascinating origins of colors through the interdisciplinary pathways of physics, chemistry, biology, and psychology in this informative resource. Learn about the physics of visible light, diffraction gratings, measurement of colors, basic color theories, and more. Explore how colors are generated in nature, such as in rainbows, bubbles, and the sky, through processes like refraction, diffraction, and selective reflection. Delve into the chemical aspects of color creation, including the emission spectra of different elements and the absorption properties of organic compounds. Uncover the secrets behind why certain objects appear in specific colors and how our perception of colors is influenced. This educational journey will broaden your understanding of the colorful world around us.
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Where do colours come from?Grzegorz KarwaszAndrzej KarbowskiAnia Kamińska*Krzysztof SłużewskiDidactics of Physics Division, Institute of PhysicsFaculty of Physics, Astronomy and Applied Informatics, Nicolaus Copernicus University in Toruń* Pomeranian Pedagogical University, Słupsk, Poland dydaktyka.fizyka.umk.pl
UltraViolet UltraViolet InfraRed InfraRed What are the colours of a rainbow? ? Tęcza na suficie http://dydaktyka.fizyka.umk.pl/Wystawy_archiwum/z_omegi/tecza.html (foto S. Lorenzo in Banale, GK, 19.09.2014)
Where do colours come from? • Physics • Chemistry • Biology • Psychology = Intersdisciplinary pathways [please copy] Visible ligth: 380 nm – 760 nm 1.65 eV – 3.3 eV
What colour is the pink lamp? Diffraction gratings:
The same? helium nitrogen (N2)
How do we measure colours? 2 lampy
What are the basic colours? USA filters In print (i.e. subtraction): cyan, magenta, yellow Window in one Berlin shop (2005) In emission (i.e. addition): red, green, blue TV set in one of Paris hotels (2004)
What are the basic colours? Red: ~ 600-700 nm Green: 495-570 nm Magenta: 380 – 500 + > 600 nm teachersource.com (USA)
Physics: diffraction Δl=nλ Energy saving lamp Sunrise Colours from diffraction on a CD
Where do colours come from? Physics Refraction, i.e. different velocity of propagration for different wavelengths: n =1.4 for red, n= 1.45 for violet
Where do colours come from? Physics Morpho Menelaus: male vs female Colours from diffraction on gratings of the wing
Why the sky is blue? Separation of colours by selective diffusion (scattering)
More, complementary sky colours Foto: Carmen Busco, Sao Paolo With kind thanks!
Atmospheric spectroscopy Isola di Rodi, Foto Federico Fedrizzi Rayleigh scattering Berlin, 22.06.2005,photo GK
Where do colours come from? River Separation of colours by selective reflection/ absorption in water (blue is transmitted into water, red is reflected)
Where do colours come from? – Sunglasses Colours from selective reflection Colours from absorption
Swarovski’s piramide (and sphere) Brown, deep blue, yelowish - these are not basic colours: refraction in the piramide + selective reflection from bottom layer .
What colours are soap bubbles? Basic colours in absorption (in print): magenta, cyan, yellow= double colours in emission: magenta=blue + red, etc. .
Colours of soap bubbles Constructive interference of reflected ligth: . http://www.amazingbubbleman.com/shared-links/
UltraViolet InfraRed What are the colours of rainbow? n=1,343 n=1,332 Tęcza na suficie Blue comes from a lower angle http://dydaktyka.fizyka.umk.pl/Wystawy_archiwum/z_omegi/tecza.html (foto S. Lorenzo in Banale, GK, 19.09.2014)
UltraViolet InfraRed What are the colours of (a) rainbow? Tęcza na suficie http://dydaktyka.fizyka.umk.pl/Wystawy_archiwum/z_omegi/tecza.html (foto S. Lorenzo in Banale, GK, 19.09.2014)
What are the colours of rainbow? Magenta? http://dydaktyka.fizyka.umk.pl/Wystawy_archiwum/z_omegi/tecza.html (foto S. Lorenzo in Banale, GK, 19.09.2014)
What are the colours of rainbow? Several diffraction series, depending on droplets’ sizes
Where do colours come from? Chemistry The emission spectrum of hydrogen (a) and helium (b) Chemistry, i.e. electrons with energies according to Bohr, Schrödinger and Pauli
Where do colours come from? Chemistry + Physics Atoms in crystaline electrostatic field: a) quartz: SiO2 b) amethyst: Fe+2 in SiO2 c) azurite: CuSO4 Saphire: Fe+2 in Al2O3
Physics: non-isolated atoms Atoms in crystaline electrostatic field – energy levels get shifted: a) Cr+3 (yellow) gets greenish in glass b) Cr+3 in Al2O3 gets red-like (= ruby) G. Karwasz, Rubiny i berlińskie szkło, Chemia w Szkole 3/2012
Where do colours come from? Organic chemistry 330px-Indigofera_tinctoria1 Absorbs yellow-to-red (=orange), so it appears blue (i.e. indigo) Usually extra electrons on double bonds
Organic chemistry: Cochenille red[czerwiec] Absorbsviolet-to-yellow, so it appears carmine-red A. Withney et al, Applied Spectroscopy 61 (2007) 994
Tonic water: absorption and emission bands are shifted http://chemwiki.ucdavis.edu/Core/Analytical_Chemistry/ Analytical_Chemistry_2.0/10_Spectroscopic_Methods/10F%3A_Photoluminescence_Spectroscopy http://www.olympusmicro.com/primer/techniques/confocal/fluoroexciteemit.html
Jabłoński diagram e.g. chlorophyll Fluorescence („immediately”) Phosphorescence (delayed)
Why chlorophyll is green? absorption and emission spectra of chlorophyll
Chlorophyll does not absorb green! chlorophyll solution illuminated lasers:(b) violet, (c) green and (d) red (a) is the chlorophyll solution seen in white ligth and (e) is water in red ligth M. Gagoś, G. Karwasz, Chemia w Szkole (2012)
And what in theew in this bottle? absorption and fluorescence spectra of 7-hydroxycoumarin simplified Jablonskidiagram Probably nothing for kids
Changing pH↔changing equilibrium Pelargonia, kompot z wiśni, zasada Flavonoids, caretonoids, etc. M. Gagoś, G. Karwasz, Colour and chemical Structure, Chemia w Szkole 3/2012
Absorption curves 2 intersections: 3 different forms
The role of the solvent: shifiting levels 4- dimethylamino-4’nitrostilbene
How can we see infrared? Proszę wyjąć komórki Infrared sensors of vipers photo GK i https://it.wikipedia.org/wiki/Crotalus
Why there is no blue flowers (inpollinated by bees)? Baptisia austrialis (false indigo) Centaurea cyanus (cornflower) CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=173802 http://galeria.swiatkwiatow.pl/zdjecie/chaber-blawatek,110360,721.html
Bees see violet, but not blue! Bees’ eye is different from human. Bees eye is best to see solid colors, especially yellow, but seesalso ultraviolet (maximum sensitivity of 344 nm). Bees can see the contrast of green and brown for them is black. G. Karwasz, On the Track of Modern Physics, UMK
Colors, the eye of the bee Cherry flowers in UV
Butterfly impressionst 15 different colour receptors (other butterflies only 4, including UV) http://www.sciencemag.org/news/2016/03/butterfly-has-extreme-color-vision?utm_campaign=email-news-latest&et_rid=35353469&et_cid=327254
Colors, the eye of artists Claude Monet, Ponte d’Argenteuil
Colors, the eye of artists: no automatic white adjustment Cathédrale de Rouen