Students learn in high school that molecules must be in contact to react chemically. But what if that’s not always true? It’s that idea, which challenges textbook “laws,” a team of theorists explored. They showed that even though it is in a completely different container from reactants, a catalyst could make a reaction happen. That is, a catalyst caused nitrous acid to change shape without touching it. The team’s theory challenges conventional wisdom about what it takes to make a reaction happen.