Seeing the first stars
Computer simulations show how the universe may have created its initial generation of stars.
The first stars were born out of the darkness that reigned in the universe after the background radiation cooled below naked-eye visibility. They started as small density fluctuations in the dark matter that dominated the universe. By the time the universe was some 100 million years old, the dark matter in the higher density regions had started to collapse under the influence of gravity. Ordinary hydrogen and helium gas, a small percentage of the mass accounted for by dark matter, started to fall toward these concentrations.