Two that come to mind are: A) Versions of the double-slit experiment which appear to show that subatomic particles can affect past events, which challenges our understanding of the “arrow of time”, and B) Quantum entanglement, which appears to show that information can be conveyed instantaneously over great distances (contrary to the theoretical “speed limit” of the universe), which challenges our understanding of the nature of space. oh, and C) Lady Gaga