To understand why this is so puzzling, you have to understand how galaxies are thought to evolve. In the early universe, matter was scattered, thin, and uneven, gradually pulled by gravity into clouds that collapsed to form stars, which then clustered into galaxies over enormous periods of time. But what Webb saw suggested that this entire process had already been completed…too quickly. That galaxy had not only formed, but had thrived. The laws of astrophysics wouldn't allow it. It was like finding a fully grown, century-old redwood tree sprouting from freshly planted soil.
