Shoya Ogawa

Inside an atomic nucleus, particles aren't just tossed together any which way. Sometimes two protons and two neutrons huddle into a tight quartet — a mini-collective known as an alpha cluster. Think of it as a family that sticks together in a crowded building. Knocking this quartet out of the nucleus and seeing how it lived there is a job for a fast proton.

A stone falls into a pond, and ripples spread across the water. If the pond is choppy, with waves coming from all directions, the pattern gets more complicated. That's roughly how spacetime behaves around a black hole when something perturbs it: it vibrates, emitting gravitational waves.