The Carbon Universe

Before I even knew anything about biology, mathematics or astronomy, I was always captivated by the mysterious shapes of seashells. Like computer models of mathematical equations, they always looked man-made to me. Their organised, perfectly symmetrical and geometrically accurate shapes came in sharp contrast to the disorderly, amorphous and irregular shapes of everything else around them.

Growing up on a beach, there was always ample opportunity to spend hours and hours sifting through the sand and stones, discovering more of these mathematical marvels where magnificent creatures once meticulously built their shells. Sometimes they were as tiny as grains of sand, and I would use a magnifying glass to see them. By the time I was a teenager my room was stacked full of boxes and glass jars of sea shells arranged by species, colour and size.

I remember the first time I saw a snail-like shell, even though I was only a few years old. I followed the spiral geometry of the shell with my eyes and realised that it grew in an exponential fashion into infinity, possibly forever. I imagined that there was a snail somewhere deep in the ocean that had never stopped growing, maybe a nautilus that was as tall as an undersea mountain, who just kept growing until it took over the world. I could see this exponential infinity in other shells as well. Scallops looked like sun rays radially expanding into infinity, or like the tail of a comet. Somehow all of these sea shells were a reflection of the physical and mathematical laws of the universe.

But they all seemed to stop growing very abruptly, just when they were at the peak of their geometric expansion. How did they know how and when to stop?

The oceans turn out to be the biggest carbon sink on Earth, bigger than the forests. As carbon dissolves into the ocean, various organisms convert it to calcium carbonate used in building their shells. Sea shells have been a major regulator of our atmospheric carbon and have shaped our modern atmosphere, removing excess CO2 from the air and over time turning it into minerals. The famous white cliffs of Dover are composed 100% of the shells of microscopic algae called foraminifera, deposited over millions of years.

Like all Earth’s species except humans, foraminifera self-regulate their expansion. They are part of the planet’s self-regulating carbon cycle, halting their growth before they even become large enough to be seen by the naked eye. By controlling their size, and their population, they keep the balance between carbon source and carbon sink.

In fact our oceans are similar to the universe, balancing the amount of free stardust and stardust incorporated into the various celestial bodies. If carbon is the stardust, then tiny snails resembling the Milky Way are the galaxies. Sea urchin skeletons are stars, and scallop shells are little supernovas and shooting stars. Our ocean is a micrography of our universe. Any interference will disturb the entire cycle. How can humans mimic the seashells and stop growing?

(From the book Photographic Heart)

George is a chemist, molecular biologist and food scientist. You can follow him on Twitter @99blackbaloons , join his mailing list, or read his books