Quaternionic Relativity. I. Inertial Motion

An approach to the description of particles' relative motion, based solely upon the mathematical properties of the multiplication rule for hypercomplex quaternionic units, is suggested. The corresponding model of the space-time structure is compelled to be 6-dimensional, with a time interval being a 3-vector orthogonal to the particle displacement 3-vector. Despite the drastic difference with the standard 4-dimensional model, the quaternionic scheme leads to results equivalent to those of special relativity.