Office of High Energy Physics

The birth of the universe

What started the big bang? How did space, time, matter and energy take the forms that we see today? Can we work backward to unravel the history of the universe?

After the big bang exploded with enormous energy, the universe began the cool-down that has lasted until our own time. The resulting chain of events is a cosmic drama with many acts, dramatic transitions and a host of actors appearing and disappearing along the way. The early scenes played out at unimaginable temperatures and densities, the stage set by the fundamental properties of particle physics. These processes had to be finely tuned to yield a universe capable of forming the galaxies, stars and planets we observe today. Did some undiscovered fundamental laws determine the conditions that allowed us to exist?

To reconstruct the cosmic story, telescopes and space probes detect the relics from the early universe, and particle accelerators recreate and study the extreme physics that characterized the stages of development and the transitions between them. As we begin to understand the cosmic past, we can look to the future of the universe and predict its ultimate fate.