  Based on Lorentz invariance and Born reciprocity invariance, the canonical
quantization of Special Relativity (SR) has been shown to provide a unified
origin for the existence of Dirac's Hamiltonian and a self adjoint time
operator that circumvents Pauli's objection. As such, this approach restores to
Quantum Mechanics (QM) the treatment of space and time on an equivalent footing
as that of momentum and energy. Second quantization of the time operator field
follows step by step that of the Dirac Hamiltonian field. It introduces the
concept of time quanta, in a similar way to the energy quanta in Quantum Field
Theory (QFT). An early connection is found allready in Feshbach's unified
theory of nuclear reactions. Its possible relevance in current developments
such as Feshbach resonances in the fields of cold atom systems, of
Bose-Einstein condensates and in the problem of time in Quantum Gravity is
noted. .
