ODE TO CELSIUS

When in Uppsala this Summer, I knew of Linnaeus, Carl von Linné, the ‘father of modern taxonomy’ – everything we do in classifying nature into kingdom, phylum, class, order, family, genus, and species, comes from him. For human, think 'animal, chordate, mammal, primate, hominid, homo, sapiens'. This is how we continue to impose order on biology, and in this sense, Linnaeus remains a 'hidden hand' of the modern world. The Linnaeus Garden, a botanical garden planted by him continues to grow and be maintained according to his principles, and is a tourist attraction in Uppsala. During this trip I was interested to learn that another hidden hand of modernism had also been Professor at Uppsala University. This was Anders Celsius, whose name is a real give-away, especially when swim-thinking turns to winter swimming. Anders Celsius was an amazing practical and theoretical mind - astronomer, physicist and mathematician, and Professor of Astronomy at Uppsala University from 1730 to 1744. He founded the Uppsala Astronomical Observatory, and in 1742 proposed the Celsius temperature scale which now bears his name. Ice and steam are two forms of water that Winter brings – ice swimming (I have been asked many times at what point in Winter do I stop swimming outdoors, and my answer is always ‘when the water is too solid’), and a steaming cup of tea afterwards. These extremes are framed by Celsius, and the Celsius scale is intuitive, and related directly to the physical properties of water, the most important molecule on the living earth. At zero it freezes (usually, if it doesn’t flow, doesn’t contain much in the way of minerals or salt), at a hundred it boils – liquid, solid, gas. Ice, swimming, tea - the complex made to seem simple.