... there was a great obstacle to this delayedaction-at -a- distance theory: namely, if a radiating electron, say inan atom or an antenna, were not acted upon at all by the field thatit radiated, then ... independently anticipated the absorber idea.6W. Yourgrau and S. Mandelstam give an excellent analytic historical account inVariational Principles in Dynamics and Quantum Theory (Saunders, Philadelphia, ... there an alternative version to a quantum mechanics basedon the classical Hamiltonian, which is a function of the coordinatesq and the momenta p of the system. He remarks that the La-grangian, a...