This work explains an internal contradiction (error) in the current understanding of non-Euclidean Minkowski space. This error happens because the imaginary unit <mml:math display="inline"> <mml:mi>i</mml:mi> </mml:math> in the Minkowski space is considered as a number. In order to solve this contradiction, it is explained in this work that the imaginary unit <mml:math display="inline"> <mml:mi>i</mml:mi> </mml:math> must be consider as an action sign over a vector because only direction of the vector could be imaginary, since imaginary length is nonsense. The concept on the imaginarity of vector refers to the directions of vector (as “plus” or “minus”), but not to the length value and therefore, all numbers could be considered as freely rotatable vectors. Being considered from this position, both the imaginary and real directions (not lengths) of a vector would be consistent for different observers, because they could consider different real axes.