SAN DIEGO, CA— The Green Flash is a great breakfast spot on the Pacific Beach boardwalk in San Diego. It is also an optical phenomenon seen shortly after sunset or before sunrise. "It happens ...

A green flash can occur at either sunrise or sunset but is more easily observable during the latter. On a cloudless evening, Earth’s atmospheric sunlight distortion is most pronounced when the sun is ...

IN NATURE of October 14, p. 513, Prof. Alfred Porter maintains that there are two distinct phenomena which go under the name of the green flash, and that the one most usually seen is an after ...