Webb Telescope proves galaxies transformed the early universe

In the early universe, the gas between stars and galaxies was opaque—energetic starlight could not penetrate it. But 1 billion years after the big bang, the gas had become completely transparent. Why? New data from NASA's James Webb Space Telescope has pinpointed the reason: The galaxies' stars emitted enough light to heat and ionize the gas around them, clearing our collective view over hundreds of millions of years.