Chao-Wei Tsai

Quasar W2246–0526 is a beacon lit when the universe was just 1.3 billion years old. Its light has traveled 12.8 billion years to reach us, yet even at such a distance, astronomers have spotted what had eluded them for decades: the gravitational shadow of a black hole.

Two houses with identical facades but different interior layouts: from the outside the V-shaped spectrum looks the same, but inside there are different light sources and different amounts of dust. That is exactly how the two populations of distant galaxies that astronomers have long confused appear.

A dense fog, through which only occasional headlight beams pierce. So it was in the early universe: young galaxies were wrapped in clouds of neutral hydrogen, which eagerly absorbed ultraviolet light. But sometimes gaps appeared in this shroud, and ionizing radiation burst out, making the cosmos transparent.

Since their discovery in 2007, fast radio bursts (FRBs) have teased astrophysicists with their elusive nature. These millisecond signals arrive from distant galaxies and carry colossal energy: for an instant, they radiate as much as the Sun does in a month.

In the first half-billion years after the Big Bang, galaxies grew like crazy. Gas fell in rapidly and collapsed into stars without any resistance. This period is called 'unimpeded star formation.' It's like frying pancakes on a scorching skillet without a lid: splatters fly, but nothing holds them back.