When we imagine the space beyond our own galaxy, we often expect a vast, empty void with stars scattered randomly like salt on a dark table. Instead, astronomers have discovered that galaxies are organized into an immense, interconnected structure known as the cosmic web. This episode explores how galaxies are threaded along vast filaments, gathered at massive intersections, and separated by enormous hollow bubbles. It examines the history of this discovery, from the mapping of the Great Wall in the 1980s to modern supercomputer simulations, revealing how gravity and dark matter shaped the universe from tiny fluctuations after the Big Bang.

This episode began with a deceptively simple question about what space actually looks like on the largest possible scale. I wanted to understand why galaxies are not scattered evenly, and how the invisib ...