Light Of Our Lives
August 2009: A remarkable piece of science is at work here. This tree aglow with fireflies is just one among millions in Kerala’s Western Ghats that support a bewildering diversity of living creatures, many yet to be recorded by science. The light comes from bioluminescence – light produced from within the bodies of living organisms.
Kalyan Varma, the photographer who shot this long-exposure image, has actually recorded an elaborate mating ritual showing male and female fireflies flashing their lights on and off. But why, one wonders, do they do this? Prof. Y. Liu of the Beijing Normal University (China) and Prof. R. Lindh of the Lund University (Sweden) say they have an answer: “when a flash light signal of the same frequency is exchanged between two fireflies of different sexes, a new couple is formed and mating follows.”
But, of course, the technology involved is hardly simple at all. Fireflies produce ‘cold light’ – with no ultraviolet or infrared rays. This light is chemically-generated in their lower abdomens and, depending on the creature emitting the light, may glow yellow, green, or pale red, with a wavelength ranging from 510 to 670 nanometres. Interestingly, this bioluminescent light has an efficiency of almost 100 per cent, while the chemiluminescent molecules that even the most brilliant scientists in the world have synthesised does not exceed a yield of 30 per cent. The rest being dissipated as heat.
In an era of climate change the ability to produce light without heat is going to be critical to our survival on the planet. Nature appears to have a solution to virtually every problem we might confront, but do we have the wisdom to recognise such solutions when they present themselves to us?
Incidentally, fireflies are not flies. They are actually winged beetles that belong to the Order Coleoptera (Family Lampyridae). Sanctuary has been using such images and examples to trigger the imagination of readers for almost three decades. Of course, our content does not even come close to delivering the experience of ‘being there’ in the thick of life, but the fact that it is a good ‘also ran’ is fuel enough for our purpose.
Bittu Sahgal, Editor, Sanctuary Asia, Vol XXIX No. 4, August 2009