Lightning striking the Eiffel Tower, June 3, 1902, at 9:20 P.M. This is one of the earliest photographs of lightning in an urban setting In:"Thunder and Lightning", Camille Flammarion, translated by Walter Mostyn. Published in 1906. Lightning is a flash of light in the sky caused by an electrical discharge between clouds or between a cloud and the Earth's surface. The flash heats the air and usually causes thunder. Lightning may appear as a jagged streak, as a bright sheet, or in rare cases, as a glowing red ball.