The Big Bang

The Big Bang marks the beginning of the universe’s expansion, when space, time, matter, and energy began their long unfolding.

Imagine dots drawn on a balloon moving farther apart as the balloon expands—not because the dots are racing away, but because the space between them is stretching.

The Big Bang was not an explosion from one point into empty space. It was the rapid expansion of space itself throughout the universe. In its earliest moments, the universe was extremely hot and dense. As space expanded, the universe cooled, allowing particles, atoms, stars, and galaxies to form over billions of years. Scientists study ancient light, the motion of galaxies, and the abundance of elements to understand this early history.