[Image: “The greenery on other planets may not be green,” New Scientist reports. Indeed, alien vegetation may be orange and yellow – “so the foliage would wear bright autumn colours all year round” – or even black: flowers the color of charcoal blooming over electrically charged soil. But why not transparent vegetation…? Vast equatorial jungles full of transparent plantlife, rooted on blocks of quartz, glowing from within as twin suns set behind wooded plateaus in the distance. (Above illustration by Doug Cummings @ Caltech)].
I imagine a stumbling block on the path to transparent trees would be photosynthesis itself. By definition it involves intercepting light. At 100% absorption the leaves would be black; at 1% (meaning 99% transparency) there would still be some pigment visible in the reflected light. Even the purest water is blue, if you look through enough of it.
I do like the notion of eternal autumn colours, however.
I thought the same as Anon above: if you’re not photosynthesising then why bother have leaves? But maybe they’re for some other purpose: heat dispersion, for example. Then transparency makes good sense… but so does being a perfect reflector (also useless for photosynthesis). Imagine walking through a hall of mirrors that change their orientation with every breath of hot wind … you brush against a creeper and suddenly a thousand eyes –your eyes!– are staring at you…
FWIW, the illustration is very similar to the effect of digital IR photography (i.e., using a IR-pass filter in front of a digital camera lens). Each of the R, G, and B sub-pixels are sensitive in different ways to the IR light that passes through, and you end up with some surreal coloring.
Examples:
http://scubapug.smugmug.com/gallery/549558/8/70711103#70711103
ed
Good points – I wasn’t thinking of the chemical mechanics of photosynthesis when I wrote that. But I still do like the idea of transparent plantlife…
Or, at least, 98% translucent plantlife. Whole forests of it.
It is beautiful.