ELI5: Explain Like I'm 5

Quantum foundations

Quantum foundations is the branch of science that studies the thoughts and ideas about quantum mechanics, which is the study of how tiny particles like atoms and electrons behave. It looks to answer questions such as what is the true nature of reality and how can we make sense of the strange behavior of these tiny particles. In particular, it studies how particles can exist in multiple states or locations at the same time, and how, when we measure them, their behavior suddenly becomes unpredictable.