Better one or two?

As the largest terrestrial lens, the atmosphere produces myriad interesting effects, but perhaps none so fabled as the green flash. And yet, for all of its stories, its description is recent. Any society can that can construct structures like the Pyramids or Stonehenge for astronomical purposes must surely have observed the green flash, yet it was not described in writing until 1836 when Captain George Back on the HMS Terror wrote about seeing it while on an expedition to the Arctic (

). Later, the phenomenon was mythologised when Jules Verne wrote of it in a book entitled Le Rayon Vert. He described a controversial Norse legend regarding the phenomenon which states that anyone who witnesses a green flash will always be true “in matters of the heart.” Little evidence, however, exists that this indeed was a Norse legend.

Nevertheless, the green flash is legendary and many suspect that it does not actually exist, that it is an afterimage. This suspicion is belied by the two images on the cover showing different aspects of the same phenomenon. A camera cannot record an afterimage, and furthermore, the phenomenon has also been witnessed at dawn …