For a long time, scientists have been trying to answer a pretty basic question about the universe: when did the lights “turn on”? Not metaphorically. Literally.Right after the Big Bang, the universe wasn’t the glowing, star-filled place people picture. It was dense, hot, and full of charged particles that scattered light in every direction. Even when things cooled down enough for atoms to form, space stayed dim. There were no real light sources yet. Just a massive stretch of hydrogen gas waiting around for something to happen. Then, at some point, it did.This period is known as the “cosmic dawn,” when the first stars and galaxies formed and started pumping out radiation strong enough to change the state of the universe itself. That radiation stripped electrons from hydrogen atoms, a process called reionization, and suddenly light could travel freely. The fog lifted. The universe became visible.The question has always been what actually powered that shift.For years, scientists assumed it had to be something big and intense. Massive galaxies. Hungry black holes blasting energy into space. That scale felt right for a moment that rewired the entire universe. New research suggests something else entirely.What Turned the Lights On?Using data from the James Webb Space Telescope and the Hubble Space Telescope, an international team of astronomers looked deep into a region of space known as Abell 2744, where gravity acts like a natural magnifying lens. What they found wasn’t a handful of giant cosmic engines, but a swarm of tiny dwarf galaxies. A lot of them.These galaxies are small, faint, and easy to miss, which is part of why they’ve been overlooked for so long. But according to the data, they were everywhere in the early universe, outnumbering larger galaxies by about 100 to 1. More importantly, they were producing far more high-energy radiation than expected.“Despite their tiny size, these low-mass galaxies are prolific producers of energetic radiation,” astrophysicist Hakim Atek said in a statement tied to the research published in Nature. “Their collective influence can transform the entire state of the universe.”In other words, the thing that flipped the cosmic light switch might not have been a few dominant forces. It could have been a massive crowd of small ones, all working at once.It’s a weirdly satisfying answer. The breakthrough could have come from countless small galaxies adding up to something universe-changing.There’s still more to confirm. This research focused on one region of the sky, and scientists want to know if the same pattern shows up everywhere else. But for the first time, the picture of how the universe went from dark to visible is starting to come into focus.The post Scientists Just Solved One of the Universe’s Oldest Mysteries appeared first on VICE.