How did the universe become so good at hiding quantum physics? In two new papers appearing in Physical Review Research, UC Davis and Los Alamos National Laboratory researchers introduce a new model to explain the phenomenon of decoherence, when a system’s behavior shifts from being explainable by quantum mechanics to being explainable by classical mechanics. The new model divorces the arrow of time from the go-to theoretical tool for understanding decoherence: the Caldeira-Leggett model.