Living Iridescence Dazzles Scientists
The flashing colors of butterflies and birds (peacocks being the classic example) do not come from pigments, but from black structures on a microscopic scale. How and why they do it is of great interest to scientists and engineers. Susan Milius explored this topic in Science News this week.1
The basic principle behind iridescence, whether it be on a peacock’s tail, a Morpho butterfly or swallowtail butterfly wing (11/18/2005) or an undersea comb jelly (12/19/2005) is an optical trick. Tiny repeating structures on the wing or feather reflect light in ways that cancel some wavelengths and accentuate others. The structures, called photonic crystals (10/13/2003, 01/29/2003) may look under an electron microscope like “rows of Christmas trees, fields of lattice-work honeycombs, [and] bristles that work like fiber-optic cables (but better).” The optical effects can even work using light humans cannot see: ultraviolet or circularly-polarized light.
A beetle that knows the latter trick was reported by Science Daily and PhysOrg and mentioned in the Science News article. It has a name to match its shimmering green glow: Chrysina gloriosa. The crystal structure resembles that of diamonds. Milius said the beetle’s decor reflects both left-handed and right-handed circularly polarized light. (Read about another photonic beetle in the 01/19/2007 entry.)
Scientists and engineers have been hunting for a “champion” photonic crystal that has the ideal qualities of a glittering diamond. They may have found it in this beetle, the PhysOrg article said. The crystals are made not of carbon, but of chitin – similar to fingernail material – but arranged in diamond-like crystals that reflect green light from all directions. The composite effect of green shimmering light is achieved by the beetle’s “ingenious engineering strategy.” Though “Nature uses very simple strategies to design structures to manipulate light,” one researcher said, they are “structures that are beyond the reach of our current abilities.”
How scientists would love to imitate this engineering strategy! Why? Get ready – we could have ultrafast computers that run on light instead of electricity. Optical integrated circuits with switches running at the speed of light could outperform electrons by orders of magnitude. A photonic computer could solve some problems in seconds that would take years on an electronic computer. Connect these light-speed computers to a fiber-optic network (11/16/2007) using cables with specs like those of the Venus flower basket sea sponge (07/08/2005 – “the most perfect design I have ever seen” – 04/05/2006), and we would have the makings of a new generation of ultrafast computers running on an ultrafast internet.
Other devices could change color depending on the presence of gases or vapors, without the need for electricity. And imagine the optical effects gadgets of the future could achieve by imitating nature’s photonic crystals – in toys, theaters and stage productions, electronic devices, medical sensors and who knows what else. We only have to recall the applications that sprung out of the invention of the laser to imagine what might become possible with these biologically-inspired tricks of light.
In her article, Susan Milius speculated about possible reasons animals use photonic crystals. The simplistic answer is to attract mates. But it seems costly for peacocks and moths to build and maintain these precision structures, and flashing one’s presence poses the risk of attracting predators instead of lovers. Does the male put on this show to signal his genetic fitness or health? It’s not clear the brilliant iridescent colors signal any kind of information an animal brain would find useful. Maybe the lights are just beautiful. Milius used a subtitle that said, “Iridescence could be pretty meaningful—or maybe just pretty.”
1. Milius, Susan, “How They Shine,” Science News, 173:28, pp. 26-29, June 7, 2008.
It is wonderfully inspiring to hear about nature’s incredible designs. Most articles, though, toss a fly in the ointment by speculating about evolution. The Science News article, for instance, claimed that “birds, beetles, butterflies and plenty of other creatures evolved cutting-edge optical systems long before modern technology did.” Later, it said, “The animals’ devices come from millions of years of evolutionary trial and error”. Puke attack.
Darwinists, stop stealing the light show. This is intelligent design science from start to finish. Design detection, reverse engineering and biomimetics all stem from the premise that the universe, earth and life show evidence of intelligent design. This is not religious. If you call it religion, we will return the favor and accuse the Darwinists of believing in mythical millions of years, magical mutations and voodoo selection.
