To do so, we develop the analysis of time in relation to its physical definition as an atomic footprint of irreversibility, due to interaction between atomic electrons and environmental electromagnetic fields (photons). Consequently, a hypothesis emerges: only duration has sense in relation to the physical time originated from this footprint, related to the entropy variation due to the interaction. So, if the system is subjected to reversible processes, the irreversibility footprint disappears and time (as a duration of the interaction) becomes null. Thus, in completely reversible processes the systems move only in the space component of the space time, without having any movement in the time components. So, any completely reversible system seems to be able also to disappear in a space position and to appear in any other space position, without spending time. Furthermore, two reversible systems seem to interact with an infinite space range, because we cannot measure time until the entropy production is fully generated.