2015 is the International Year of Light, a year designated by the United Nations to appreciate and learn about optical phenomena. To launch their celebrations, the Perimeter Institute for Theoretical Physics illustrated 20 of their favourite light facts.
Tip via the Physics Today Facebook page. For literally cool optical phenomena, did you catch our special on ice halos?
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https://gizmodo.com/eight-types-of-ice-halos-are-crammed-into-one-glorious-1679103669
