A talk with nothing to do with tech — titled Not Gatekeeping These Hidden Gems, on crystals in living organisms. Before tech, Jackie spent years in chemistry, biology, and physics; he likes rocks and crystals, and his first stop in any foreign country is the natural history museum.
The talk opens with what a crystal actually is — molecules lining up in a repeating order — and why that makes crystals both pretty and useful. Then it works up the tree of life:
- Bacteria — magnetotactic bacteria grow chains of magnetite (Fe₃O₄) crystals and use them as a built-in GPS, aligning themselves with the Earth's magnetic field.
- Plants — roots know which way is down thanks to starch. Specialised cells called statocytes hold dense starch grains that settle with gravity, telling the root which way to grow. Plants also use crystals for defence, packing their tissues with sharp crystals that make them painful to eat.
- Insects — (content warning: cockroach) the Pacific beetle cockroach, Diploptera punctata, is the only known viviparous roach. It feeds its young a crystallised "milk" that's about four times denser than cow's milk and one of the most nutritious substances by weight — the only known example of that way of feeding young.
- Humans — foods we think of as "rich" are high in purines, which break down into uric acid. Uric acid forms spiny crystals in the joints, and that's gout. On the useful side, otoliths — tiny calcium carbonate crystals in the inner ear — are part of how we keep our balance.
The conclusion: crystals rock, they're all around us, and nature is wonderful.