We tend to picture the nearby Universe as a map of things (galaxies, clusters, filaments). But some structures only become clear when you stop asking where matter is and look at where it goes.

Laniakea is defined that way: a basin in the velocity field, where motions converge toward the same attractor. In practice, shared motion draws boundaries more cleanly than shared location.

The intuition is simple: a still image might suggest a landscape, whereas a flow map tells you where the watershed actually is. Once peculiar velocities are reconstructed, the picture shifts. Structures that look connected can split. Others that seem fragmented fall into the same basin. Even voids start to matter, shaping how trajectories diverge.

This forms a fluid network where galaxies, including the Milky way, flow. In a fun collaboration with prof_Conradi we have used real data and available simulations to visualize that network and its dynamics, producing this stunning visualization shown below.

The plus? We have also a post for you, the usual podcast and a publicly available Github repository with a reproducible pipeline. The link to the post and materials is in the first comment.