Does the Time Dimension has to be Perpendicular to the Space-Dimensions?

INTRODUCTION: Considered are doubts regarding the choice of the time dimension as perpendicular to the three spatial dimensions of an observer. OBJECTIVES: To solve this problem, it is necessary to compare the description of the current model of reality with a model that assumes that the time dimension is linearly independent of the spatial dimensions of the coordinate system of an observer. METHODS: It was necessary to examine and compare the properties of two models of reality that fulfilled the rule of space-time interval conservation, the first where the time dimension is perpendicular to the space dimensions of the coordinate system of an observer, and the second where the time dimension is linearly independent of the space dimensions of the coordinate system of an observer.. RESULTS: The approach that assumes that the time dimension is linearly independent of the spatial dimension of the coordinate system of an observer leads to a Euclidean picture of reality, where it is possible to connect the absolute character of reality with the relativity of motion of bodies. CONCLUSIONS: Rejecting the assumption regarding the perpendicularity of the time dimension to the spatial dimensions of the observers’ reference frame seems to be a way to solve unsolved problems for 120 years and extend the capacity of the model of reality.