As if by magic, seemingly independent pendulum clocks can come together to tick simultaneously and in synchrony. The phenomenon of “self-organized synchronization” frequently occurs in nature and engineering and is one of the key research fields of Marc Timme’s team at the Max Planck Institute for Dynamics and Self-Organization. The physicists in Göttingen are part of a German-Italian collaboration which has now published an amazing discovery in Nature Communications: even quantum systems can synchronize through self-organization, without any external control. This synchronization manifests itself in the strangest property of the quantum world – entanglement.