THIS IS NOT YELLOW Magenta is not a real color The Teleology of Green The Meaning of Orange or

The Teleology of Green The Story

Colors are the smiles of Nature Leigh Hunt, 19th century poet

Oxford English Dictionary Teleology The doctrine or study of ends or final causes, esp. as related to the evidences of design or purpose in nature; also such design as exhibited in natural objects or phenomena ZOLLMAN in Phil. Trans. XLI. 299 Teleology is one of those Parts of Philosophy, in which there has been but little Progress made F. BUCKLAND in Bompas Life x. (1885) 224 This is the doctrine of Teleology: i.e. the doctrine that every organ is adapted to a special use H. DRUMMOND in Barrows Parl. Relig. II Darwin has not written a chapter that is not full of teleology.

THIS IS NOT YELLOW Philosophy

Color is our brain’s response to light. “Light” is a term that refers to a electromagnetic radiation. And electromagnetic radiation are waves of different energies that extend over a broad range: If the electromagnetic spectrum were a piano keyboard….. cosmic gamma X-rays UV Vis IR Radio induction power wavelength, nm nm frequency, Hz Hz the visible spectral region would be just one key!

Each of the “colors” of visible light has a corresponding wavelength between 400 to 700 nanometers (or nm). Is this because the eye has a specific detector (or receptor) for 565 nm yellow light? And a different receptor for 450 nm blue light? And another one for 650 red-orange light? And so on, for every wavelength between 400 and 700 nm? Seems like that would be a LOT of different types of receptors. Nature is “smarter” —and more efficient—than that. Only three different receptors for visible light are used. 565 nm Light having a wavelength of near 565 nm will look yellow to most people.

Your eyes have only three color receptors (detectors) - the RGB cones (red-green-blue) Beauty in the eye of the beholder It is the brain that interprets visible light as “having” color.

Yellow light is perceived by our eyes when two color receptors, Red and Green, are stimulated simultaneously. This is indicated on the diagram by the red and green arrows. It is the brain that interprets yellow light as “having” a yellow color.

“What about red-orange?”, you say. “Red-orange light would also simultaneously stimulate the Red and Green receptors. See?” Aaahhh…..true. But look! The relative lengths of the arrows are different. The green arrow, i.e. G-receptor, is much less stimulated than the R -receptor. So, red-orange light is seen as different from yellow light due to the ratio of R and G response.

When the R receptor gets about the same signal as the G receptor, or R = G, yellow is perceived. When the R receptor gets a larger response the the G receptor, something like R = 3G, red-orange is perceived. It is the brain that interprets color.

THIS IS NOT YELLOW Philosophy

Is there a unique GREEN “out there? Note that there is no wavelength where only the “green” cones detect

Magenta is not a real color.

Magenta is a non-spectral hue.

Magenta is not a real color.

Maxwell’s Triangle Think of the saturated red and green colors on Maxwell’s diagram as vectors. Now, imagine “decomposing” these R and G vectors into the sum of the dashed arrows.

Maxwell’s Triangle See how two of the decomposed vectors that run along the right edge of the triangle are co-linear but point in exactly opposite directions? They cancel each other. This leaves the shorter vectors components these vectors have the same direction and point from yellow. They represent the yellow “product” from adding red and green.

Maxwell’s Triangle Blue + Yellow = White?! Blue + yellow vectors point in exactly opposite direction and cancel to make white.

The Teleology of Green The Painting

The Difference Between Art and Science From this Munch painting of someone pained on a bridge, hands held to ears, the observer could scrape an orange micron speck. He could mount it on a slide, fine-tune the fast beams that circle under parking lots and football fields, prodded on by magnets’ handless shove, focus, for that is his craft, the stone particles (fancy calibrated stones) to jarring graphed impact in the paint. The search is for the force of the scream. But the particles’ pry is too strong—they shock loose the paint molecules, in sound demonstration of the uncertainty principle. The painting hangs; Norwegian sky and harbor pick up the scream, beam it into the observer’s skull. There, echoing, effect change. Roald Hoffmann, chemist, poet Nobel Laureate

The Scream Edvard Munch 1893

Anxiety Edvard Munch

The Difference Between Art and Science From this Munch painting of someone pained on a bridge, hands held to ears, the observer could scrape an orange micron speck. He could mount it on a slide, fine-tune the fast beams that circle under parking lots and football fields, prodded on by magnets’ handless shove, focus, for that is his craft, the stone particles (fancy calibrated stones) to jarring graphed impact in the paint. The search is for the force of the scream. But the particles’ pry is too strong—they shock loose the paint molecules, in sound demonstration of the uncertainty principle. The painting hangs; Norwegian sky and harbor pick up the scream, beam it into the observer’s skull. There, echoing, effect change. Roald Hoffmann, chemist, poet Nobel Laureate