Einstein's mathematical deception: Special relativity conceals that it changes the speed <i>c</i> along the X-axis in the stationary frame of reference

In his famous paper “On the Electrodynamics of Moving Bodies” [A. Einstein, Ann. Phys. 17 , 891 (1905)], Einstein derived kinematic time dilation by considering a coordinate system k that moves relative to a stationary coordinate system K along the X-axis, where he let the x-axis and the X-axis of the two systems coincide. Einstein defined for light beams moving along the X-axis, which are emitted from the origin of the coordinate system k to the mirror and back to the origin of the coordinate system k, no matter in which direction a light beam moves, each time interval by the sum of the two time intervals x ′/( c − v ) and x ′/( c + v ) divided by 2. Afterwards, Einstein defined x ′ as infinitely small, so that x ′ disappeared and he obtained the differential quotient 1/2[1/( c − v ) + 1/( c + v )]∂ τ /∂ t , from which the kinematic time dilation factor γ squared results if the two terms in the brackets are added. However, after x ′ has disappeared, the change in time is now only defined by the speed c of light and v , where v is a uniform speed. This means that the two quotients within the brackets cannot be added without changing the value of c . By adding the two quotients within the brackets of the differential quotient 1/2[1/( c − v ) + 1/( c + v )]∂ τ /∂ t , Einstein's special relativity (SR) mathematically creates in the stationary frame of reference two different values for the speed of light that differ from the value of c . Einstein was able to conceal that SR mathematically alters the laws of nature because his derivation of kinematic time dilation along the X-axis does not change the letter “ c ,” but only the value of c . Einstein's miracle year is demystified here and a theory of relativity without mathematical tricks is presented.