Due to his research on relative motion in optics and electromagnetics, he advanced a series of modifications to the traditional transformations that eventually led to the equations advocated by Larmor, Poincaré, Einstein, and others.8 Hence, Poincaré gave the name ‘‘Lorentz transformations’’ to these new equations, although Woldemar Voigt had published equivalent equations in 1887.9 In 1909 the simpler and older transformation equations were named the ‘‘Galilean transformations’’ by Philipp Frank.10This is a typical strained effort to credit Einstein, even tho the Lorentz transformations were named after Lorentz before Einstein wrote about them.
What distinguished the new transformations in Einstein’s work in comparison to the equivalent equations in the earlier work of other physicists was that Einstein introduced such transformations by means of general kinematic arguments, rather than introducing them exclusively for the solution of problems in optics and electrodynamics.
The explanation is nonsense. Lorentz devised the transformations to explain the Michelson-Morley experiment and other electromagnetic puzzles. So yes, Michelson-Morley was an experiment on the speed of light, so it was for optics and electrodynamics. Einstein's method was also for optics. After all, the transformations involve the speed of light and he used light throughout his analysis.
Kinematics is a word meaning the study of motion without considering forces. It has nothing to do with whether optics and electrodynamics are used. Einstein believed that he had a conceptual simplification in explaining Lorentz's theory by first describing the consequences when no forces are involved.
But Einstein failed to get to the heart of relativity. Poincare and Minkowski introduced the transformations with non-Euclidean geometry, and that is the preferred method today, and has been since about 1908. That is, they removed the motion and the forces, and made it a theory of spacetime geometry. Then they showed how the motion and forces are affected by the geometry. They were not influenced by Einstein who did not even understand what they did.
Martinez is typical of Einstein idolizing scholars. They know about the work of Lorentz and Poincare, so they are hard-pressed to say that Einstein did anything original. The closest they can come is to mumble something about kinematics, meaning that Einstein took Lorentz's equations and observed that they apply when forces are absent. They try to trick you into believing that this was a step towards the spacetime geometry, but it was not, as Poincare wrote his 1905 paper on the spacetime geometry before Einstein's paper was published.