Lightning streaks across the sky in Tyler, Texas as a powerful line of thunderstorms, several spawning tornadoes moved across Texas, on April 3, 2012. (AP Photo/Dr. Scott M. Lieberman)

Worldwide, lightning strikes around 50 times every second (more than 4 million times every day). Electrical imbalances generated by turbulent skies are suddenly balanced by a spectacular discharge tracing across a darkened sky — a display that is both frightening and awe-inspiring.