Physicist and head of the climate analysis department of the Royal Netherlands Meteorological Institute. Like Vincent Icke, Dr Können was also impressed by Marcel Minnaert’s Nature of Light and Colour in the Open Air, notably the second volume, Light and Colour in the Outdoors. Können is a keen observer of light phenomena and took part in a three-month mission to study coronas and aureoles in Antarctica.

Können agrees that the light in Holland differs from that in other parts of the world. Perfectly clear skies can be seen in Scotland, Antarctica and Norway, whereas the atmosphere in southern Europe tends to be hazy. But the concept of ‘Dutch’ light, he says, is a figment of the imagination. Können is evidently ambivalent on the subject. If there’s anything special about the light, it’s to do with the horizon. He describes Holland as unique by virtue of its flatness and its unbroken horizon, which usually has a bank of cloud hovering above it. But he’s sceptical about the hypothesis that the light has changed as a result of land reclamation in the Zuyder Zee.