Einstein famously hated this idea, wanting all cause-effect relationships to be “local” (meaning limited in speed to c). He petulantly referred to it as spooky action at a distance. Bell’s theorem gave it credibility, and now a series of experiments are proving it empirically.
A nice 6-minute film in which the viewer looks back, from a rocketship, as she moves from the surface of the planet through the universe. Various scientific landmarks and facts are displayed over the course of the trip. Good for kids and context.