Eclectic Perambulations in the Noosphere
Courtesy of Konrad Polthier and Konstantin Poelke, Free University of Berlin
"Complex functions are important in many areas of mathematics, physics and engineering. A complex function is one in which both variables are complex numbers. The picture shows the visualization of a complex function using a specifically designed color scheme.
Following a technique called 'domain coloring,' the color scheme assigns a certain color to every complex number, inducing a coloring of the function domain according to its values at every point. So using this picture, you can explore properties of the function by easily spotting zeroes (black spots) or singularities (white spots). Contour lines indicate how the function deforms the complex plan."
"Try to imagine reddish green — not the dull brown you get when you mix the two pigments together, but rather a color that is somewhat like red and somewhat like green. Or, instead, try to picture yellowish blue — not green, but a hue similar to both yellow and blue.
Is your mind drawing a blank? That's because, even though those colors exist, you've probably never seen them. Red-green and yellow-blue are the so-called "forbidden colors." Composed of pairs of hues whose light frequencies automatically cancel each other out in the human eye, they're supposed to be impossible to see simultaneously.
The limitation results from the way we perceive color in the first place. Cells in the retina called "opponent neurons" fire when stimulated by incoming red light, and this flurry of activity tells the brain we're looking at something red. Those same opponent neurons are inhibited by green light, and the absence of activity tells the brain we're seeing green. Similarly, yellow light excites another set of opponent neurons, but blue light damps them. While most colors induce a mixture of effects in both sets of neurons, which our brains can decode to identify the component parts, red light exactly cancels the effect of green light (and yellow exactly cancels blue), so we can never perceive those colors coming from the same place.
Almost never, that is. Scientists are finding out that these colors can be seen — you just need to know how to look for them."
by John Adam
"The photo above shows a chunk of scalloped ice, about 65 ft in width that broke off from the Sawyer Glacier near Tracy Arm Fjord in southeastern Alaska. Note the pure blue color emanating from within the “chasm.” The mechanism responsible for producing this robin’s egg blue color, as well as the blue color in deep snow, is essentially the same as that giving deep water its blue color. The longer wavelengths (yellow and red light) present in the incident white sunlight are preferentially absorbed by ice crystals. As a result, what we see is what’s not absorbed -- reflected light that’s dominated by the green and blue portion of the spectrum. In general, the thicker the ice the greater the absorption, and thus the bluer the color."
Ants turn all colours of the rainbow in these amazing photos, taken as they eat specially dyed sugar drops.
"Dr Mohamed Babu set up the shots after his wife Shameem noticed that ants turned white when they sipped spilled milk.
The scientist mixed sugar drops with edible colours red, green, blue and yellow and placed them in his garden to attract the insects. As the eager ants scoffed the sweet treats the colour of the sugar they had chosen could be seen in their transparent abdomens. Some varied their choice, creating different colour combinations inside them."
"Ever since I first saw the cover of “Information is Beautiful” I have always loved David McCandless‘ iconic “Colours in Culture“.
You can view the final interactive Flash version here:
