• The definition of time ( ) is related to a duration, so, it satisfies the requirement of Einstein that any definition of time must be related to a clock. In relation to the EPR paradox, the results can be summarised stating that without any interaction, time cannot exist, as previously suggested, as a consequence of the interaction between electromagnetic waves and matter. Now, following the original EPR gedanken-experiment , we consider two spin-1/2 particles, generated by the same source, A and B, which move in opposite directions. These particles can be detected only if they interact with an experimental setup. Until they interact, from the previous considerations, they are only in spatial dimensions, because time flow starts only from their interaction with an observer. So, independently by their distance, the two systems are not aware of being separate, because they aren't subjected to time dimension. Before the interaction with the observer, their state function is :