Abstract

In vector calculus the addition of two vectors means no more than the addition of their components. According to Special Relativity Theory (SRT) the addition of two velocities signifies more than that. Apart from adding the components we have to divide their sum by a coefficient 1+(v/c)(u/c), which presence indicates that the velocity is not a vector in SRT. If the velocities in SRT were vectors they should be added up as vectors. The ratio of velocities v/c should not be considered as the hyperbolic tangent of an angel. The coefficient mentioned above appeared as the result of the baseless introduction of hyperbolic functions to the SRT formulae. On that basis the formulae although fully consistent are evidently wrong. We have shown that they can easily be reduced to the correct formulae of the Galilean Transform. Also we have shown that in the case of a 3D space there are three different coefficients and three corresponding different times for one moving object. Therefore there is a choice to be made. On the one hand by dismissing the hyperbolic functions from SRT we annihilate SRT and on the other, by accepting them we reject (commonly accepted) the rules of vector calculus and obtain in 3D case, three different times instead of one.