It occurred 13.7 billion years ago, an explosion that created all matter and energy, plus space and time themselves. The universe expanded from a very hot, condensed “singularity”—the likes of which can be found today in black holes. Particles sped away on the expanding seas of space-time, coalescing into galaxies and stars; sometimes a star exploded, sprinkling the void with atoms that eventually formed our bodies. We are stardust. The cosmos continues expanding, its galaxies like dots on an inflating balloon.
