If you put chalk under a powerful microscope—white cliffs of Dover type chalk, not the modern blackboard variety—you will see something like this
Because it's not just a rock. It's an accumulation of ancient skeletons: the armored husks of single-celled, ocean-dwelling plankton
Because it's not just a rock. It's an accumulation of ancient skeletons: the armored husks of single-celled, ocean-dwelling plankton
These tiny photosynthetic creatures, known as coccolithophores, are extremely abundant. When their populations boom they can turn England-sized swaths of ocean an ethereal turquoise—a phenomenon visible from space
Coccolithophores are crucial to the ocean’s food webs, produce huge amounts of breathable oxygen, and have the power to alter the Earth's geology and atmosphere. Scientists are studying how they might sway climate change and vice versa
per @richardson_beth, the photo of coccolithophores is by Jeremy R Young of UCL. See nature.com/articles/natur… & genome.jgi.doe.gov/Emihu1/Emihu1.… & ucl.ac.uk/earth-sciences…
A passage from Thomas Henry Huxley's 1868 lecture/essay "On a Piece of Chalk"
ebooks.adelaide.edu.au/h/huxley/thoma…
ebooks.adelaide.edu.au/h/huxley/thoma…
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