Kai Zhu

Take a child's spinning top and set it on the table. It spins steadily, with all its parts moving in the same direction. Now toss a handful of beads onto the floor and blow on them: each bead will fly its own way. That's roughly how astronomers distinguish two types of large galaxies: 'spinning tops' (fast rotators) and 'beads' (slow ones with chaotic stellar motion).

A dance of hundreds of particles: some pairs spin slowly and gracefully, others twitch in a frantic rhythm. To understand the essence of the dance, you need to watch the slow movements: they are the main choreography of the system. In molecular science, such slow movements are called 'slow modes,' and they determine how a protein folds into a ball or how a drug binds to its target.