Early galaxies burned bright with fresh gas, reshaping our cosmic origin story

New JWST observations and ColdSIM simulations show that the first galaxies in the early universe formed stars at a frantic pace using pristine gas rather than recycling material. The simulations reveal a shift from cold, dense gas to a warm, low-density phase during the epoch of reionization, plus a surprisingly low stellar return fraction. As a result, these infant galaxies depleted their gas quickly, implying a more aggressive, gas‑driven mode of star formation than current models predict. This work reshapes our understanding of cosmic origins and will be tested further by JWST and future facilities like the Square Kilometre Array.