This is a broad-audience public lecture names "KITP Blackboard Lunch" I gave at the Kavli Institute of Theoreical Physics (KITP) at the University of California at Santa Barbara (UCSB) to discuss the physical basis of the core subjects of the KITP 7-week program "Emerging Regimes and Implications of Quantum and Thermal Fluctuational Electrodynamics" I organized at KITP. This lecture was devoted to the KITP permanent staff and to all the participants to the several KITP programs. Here the recorded video: "https://online.kitp.ucsb.edu/online/bblunch/antezza"