Yiheng Lin

An ordinary magnet makes a compass needle turn, but it doesn't stop the needle from moving forward. But if you twist a magnetic field into a knot, it can trap a particle in place, like a snare. This phenomenon is called an 'Aharonov–Bohm cage': the particle's waves cancel each other out at some points and reinforce at others, leaving only tiny 'islands' where it can exist.

Biologists often tag cells with glowing molecules — it's like searching for a dim light in the smoke. The light quickly fades, and the smoke creates interference.