In December 2012, Deborah Carter of Maun, Botswana, was visiting a friend in Cairns, Australia, when the “sky started to darken and the wind got up, and we knew we would have to quicken our step in order to escape the incoming rain. So we walked a little faster, and then I noticed a rainbow forming.” Carter snapped a few photos of the sight with her iPhone and later asked me about their details. What especially fascinated her was the “difference in the color of the sky below and above the rainbow.”
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