"Dancing in the Dark"
The properties of the galaxies are shaped by the dynamics of the dark matter at large scale. On this picture coming from a cosmological simulation, each dot is a galaxy. The white lines represent the matter filaments. The red and blue area on the slice perpendicular to the direction of the filament indicates the rotation of the dark matter. Galaxies embedded in a filament will have their angular momentum aligned with the filament, but in an opposite direction if they are either in a blue or either in a red area.