Light is sometimes used as a metaphor for life — you might “put someone’s lights out” or tell them they’re “the light of your life.” But life and light aren’t just linked poetically. When sperm meets an egg, there is a real flash of light. So in a way, life and light are one and the same.

— Read on curiosity.com/topics/when-sperm-meets-egg-sparks-literally-fly-curiosity