As the sun rises above a mountain ridge populated with pine trees, a short-lived but spectacular light scattering effect off the pine needles is visible. It was noted by the Victorian physicist and mountaineer John Tyndall in his two mountaineering books, and this paper describes Tyndall’s observations, discusses his and Professor Necker’s descriptions, and illustrates the effect with a modern photographic image, as well as commenting on possible explanations of the phenomenon. A rarely cited reference to a memorandum of Babinet has been found that gave Necker’s description as a spectacular example to illustrate his theorem “Babinet’s Principle.”
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