Looking East at Sunset

Wotjow, commons.wikimedia.org
Anticrepuscular rays, 2011. Wotjow, commons.wikimedia.org

I have written about science being creative, and here’s a great story along those lines: the poet and priest Gerard Manley Hopkins published in the scientific journal Nature*. Hopkins’ contribution to science took the form of two letters, A Curious Halo and Shadow-Beams in the East at Sunset, that were published in November 1882 and November 1883, based on observations he had made of the setting sun.

Hopkins did something most people don’t think of, and turned his back to the setting sun. What he saw was a series of rays that looked as if they were coming from the horizon at a point opposite the sun. This light-effect had already been observed by meteorologists, and is simply the shadows of clouds in front of the sun, cast from one horizon to the other. Perspective makes these shadows appear to be converging in the east, but they are in fact parallel. The technical name for them is ‘anticrepuscular rays’. Continue reading