A school science refresher: the 3 primary states of matter, solids, liquids and gases and the transitions between each one. If you’re like me you probably forget about the more obscure sublimation and deposition directly between solids and gases. And vaporisation of a liquid is evaporation, occurring at the surface, if it is below boiling point, otherwise it’s boiling.

There are some more unusual states including plasma — seen in lightning and fluorescent lights — and Bose-Einstein condensates, but mostly we’re familiar with ice cubes, water and steam.

States of matter

In some forests where the trees grow tall and straight, like those in the US Pacific Northwest, when a giant tree falls, it creates an opening in the forest canopy that lets in light for new growth to take foot. The mighty fallen tree trunks themselves provide a new surface for seedlings to take root, away from the competition of the forest floor. When this happens, the fallen tree becomes an integral part of a new ecosystem.

Such fallen trees are known as nurse logs. Sometimes, a nurse log is so successful as a nursery for the young trees that they will grow along the full length of the fallen trunk. When the original trunk finally decays, it leaves behind it a remarkable, straight line of trees.

Nurse log

Solvitur ambulando: This phrase from the Greek philosopher Diogenes translates more or less to ‘it is solved by walking’. And, indeed, there is something about walking that helps both clear the mind and think clearly.

Try a walk to get a different perspective on a problem when you’ve been banging your head against one sat at your desk. Or try a walking meeting with the bonus that you get a bit of exercise in too.

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Solvitur ambulando