The study by Jan Sperling et al. demonstrates that neither wave nor particle models adequately explain the behavior of quantum light in interferometric experiments. By using squeezed light, the researchers established correlation-based criteria that reveal the incompatibility of both interpretations. Their findings suggest that quantum electrodynamics (QED) is the only framework that accurately describes the observed phenomena, challenging the traditional wave-particle duality concept. The paper emphasizes that both wave and particle interpretations fail in specific quantum-optical setups, reinforcing the notion that classical models are insufficient for understanding nonclassical light. This research provides experimentally verifiable criteria for assessing the nature of quantum light, marking a significant advancement in quantum optics.