Earth opals

Earth opals

What has beauty worthy of poetry, the collectible variety of precious gems, contains ancient mysteries in chemistry and physics, and should be studied like our lives depend on it? Pictured above is a random selection of diatoms from a drop of seawater. These tiny creatures are as ancient as any life alive in the ocean. Their bodies are made of hydrated glass - as are opals. They form the base of the ocean food chain, where sunlight from space is turned to sugar. Oh, and they manufacture a large slice of oxygen we breath!

Diatoms are heavier than water, yet float mysteriously at the surface of the earth's oceans. By all accounts, they should sink like glass beads, which they do when they die. (Diatoms, in fact, form the bulk of the material in sediments the world over.) Yet, when alive, many diatoms show no mechanisms of active swimming. Only recently has some research come to light that hints at highly advanced nano-scale surface interactions that let them change buoyancy at will.

They contain chlorophyll of two different kinds and enhance their solar capabilities further with pigments. When they do Through photosynthesis, they produce a surprisingly diverse (and plentiful) output of monosaccharides as well as oily lipids. As much as 20% of the oxygen in earth's atmosphere today is the product of diatom respiration. Where scientists classically categorized these tiny glassy creatures by the wondrous shapes of their diaphanous bottles, or valves, much has been recently learned through direct study of their genomes. No one really knows how many different species of diatoms exist, but estimates are in the hundreds of thousands, making them the most diverse type of life on earth. They are small living crystals of infinite creative variety, powered by sunlight, and living for themselves while at the same time enabling all other life to flourish. 

Diatoms are not only of interest to marine biologists, but to genetic researchers,  physicists, and material scientists as well. Their ability to construct complex identical structures by the millions out of glass, for one, is quite *interesting* to those in the field of nanotechnology. Their improbably efficient conversion of solar energy into oil is another tantalizing process. Their huge genetic diversity hints that they have been able to laterally swap genes with one another and between other single celled organisms in ways hardly understood. They might turn out to inspire some incredible industrial applications for the ever-hungry will of humans. Still, though, on their own they are magnificent little embodiments of the very essence of life on earth. They're nature's answer to the most basic arrangement of elements, molecules, and energy on our planet. 

I thought I could write a one paragraph entry on the subject of diatoms, but everything that I read opens up more questions and involves wider and wider fields of study. Anyway, I'll conclude with a prose poem:

Down the rabbit hole of knowledge!
How deep do these glassy creatures thread?
I think they go all the way.
 

 

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