The Gleam in Nature's Eye

"...first-beginnings have no colour,
But they do differ in shape, and from this cause
Arise effects of colour variation...
Hues change as light fall comes direct or slanting...
A peacock's tail, in the full blaze of light,
Change in colour as he moves and turns."
- Lucretius, De Rerum Natura


    Light became an evolutionary force over 500 million years ago in the Cambrian era. The eye is thought to have evolved on 40 separate occasions. But the eye also registers what it's looking at. What is there has only evolved because some other creatures can see it. For example, flowers evolved their colors to attract insects, and a peacock's tail evolved to attract females.
    Light is an important source of communication medium in both nature and technology. It has been used in nature for millions of years, but, it is only an emerging field in human technology. Optical technology is a promising area of study and the most anticipated product is the all-optical computer. Computers and their silicon chip microprocessors run on electrical impulses. We just need to know if it could be powered by light. The reason why this is such an anticipated product is that light can be pulsed 10 times faster than electricity and beams can cross each other without interfering. A problem with this is that light is very hard to control and it doesn't bend willingly. Eventually scientists were able to make a device that would make light bend and that is the photonic crystal. It works like the transistors in a silicon chip by only allowing light of certain wavelengths to pass through.
    The idea of the photonic crystal was proposed when the internet was being developed and they needed a vast increase in capacity of the telephone network. The first success of creating the photonic crystal was by Eli Yablonovitch in 199. His team spent four years drilling millions of 6 mm holes into solid blocks in a diamond like pattern. This material was later called Yablonovite. This started the long road to miniaturization.
    Butterflies and some marine creatures send optical messages by means of a nano scale photonic crystal. They have surface patterns with dimensions to the wavelength of various colors. The reason why the colors change when we shift our viewpoint is that the movement drastically changes the angle of rays of light from the reflecting surfaces. The most eye catching butterflies to show iridescence is the bright blue Morphos. Their wings are covered in scales that look like shingles on a roof top. The scales have ridges running down them. The intricate structure has a purpose; it controls how the light reflects off the scales. The Morpho's optical system evolved to show a strong blue from any angle. This pattern has been used commercially and is named after the butterfly: Morphotex fabric. It was created by the Teijin Corporation of Japan with collaboration with Nissan Motor Co. The Fabric has been used in the front seat covers of the Nissan Silvia Varietta Convertible. Below is a picture of the Morphotex fabric in comparison to the Morpho butterfly.