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====== Nature of Time (A)symmetry in Modeling of Physical Systems ====== The paper deals with the concept of the (a)symmetry of time (time arrow) in modeling of realistic physical systems with particular emphasis to electromagnetic phenomena. Contrary to the fact that the Maxwell’s equations of electromagnetism are time invariant, (there is no preference regarding the direction of time), the usual solutions of the wave equations derived from Maxwell’s equations are related to //the retarded potentials//, thus dropping out the //advanced potentials// as non-physical. The //retarded potentials// represent the electromagnetic waves detected at an observation point once they left the source. The //advanced solutions// are related to the waves arriving at the detector before they leave the source, though mathematically possible, which are never observed in nature. These waves are eliminated through prescribing certain set of boundary and initial condition, respectively. However, one can mathematically construct the time reversal version of electromagnetics which has been successfully applied in some engineering applications. Time reversal or //T//-symmetry is related to the symmetry of physical laws under a time reversal transformation: $t\to -t$.