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Plate 53 How the Cochlea Takes Sound Apart

Life & Medicine

Sunflowers, starling flocks and the inner ear, and the MRI scanners and surgical robots of the hospital.

9 plates

Plates 9

  1. Plate 06 The Arithmetic of a Sunflower LifeStart here Count the spirals its seeds make, and you will arrive at a famous sequence of numbers. Open
  2. Plate 09 No Bird in Charge LifeStart here Thousands of starlings turn together at dusk like a shape-shifting cloud of smoke. No one is giving orders. Open
  3. Plate 16 Where Spots and Stripes Come From LifeGoing further A leopard’s spots and a fish’s stripes may come from the same simple recipe: two ingredients, one fast and one slow. Open
  4. Plate 20 The Breathing Planet LifeStart here A tree’s wood is made mostly from air. Every summer the northern forests breathe in together, and the whole atmosphere holds less carbon dioxide. Open
  5. Plate F03 MRI Scanner MedicineGoing further A clinical MRI scanner: a superconducting magnet, gradient coils and RF coils, one inside another. Hydrogen nuclei precess in the field; their signal fills k-space, and a Fourier transform turns it into an image. Open
  6. Plate F04 Surgical Robot MedicineGoing further The surgeon operates from a console nearby; the arms pivot each instrument about its incision. Hand motion is scaled down and stripped of tremor on its way to a tip 8 mm across. Open
  7. Plate 48 A Pattern Painted One Line at a Time LifeGoing further The triangles on a cone shell are painted at the edge of its opening, one line at a time. Each line is set by the cells along that edge: where one grows strong, it holds its neighbours back. Open
  8. Plate 52 Hearing a Moth in the Dark LifeStart here A bat hunts at night by its own voice. It sends out calls too high for us to hear and listens for the echo off a moth; how late the echo comes back tells it how far away the moth is. Open
  9. Plate 53 How the Cochlea Takes Sound Apart LifeStart here Sound entering the ear ends up in a coiled tube. A membrane inside it is pushed into a wave that swells highest near the entrance for high notes and far along for low ones. A few thousand hair cells turn that motion into nerve signals. Open