Diamond Carousel: How Magic-Angle Spinning Makes Nuclei Glow
Imagine a carousel carrying not children but tiny magnetic needles inside diamond dust. Usually these needles point randomly, and their signal is lost in noise. But if you tilt the carousel at a special angle and shine a green laser on it, the needles start aligning in one direction. That is exactly what physicists did with diamond particles, spinning them at 54.74° to the magnetic field.