Yingjie Zhang

Turn off the stove, and water stops boiling almost instantly. In the world of catalysis, researchers expected a similar picture: stop the reaction, and all intermediate particles vanish right away. But fresh observations of platinum nanoparticles tell a different story.

Light passing through a glass of murky water dims — some of it is absorbed. That's how many liquid-analysis instruments work: they measure how much light was lost and infer the composition from that. But if the liquid is heterogeneous, like soup with chunks, a single number isn't enough: you need to know where exactly more absorption happened.