How did one of albert einstein's experiments lead or not lead to another?

This is what I found hope it helps. Einstein recalled how, at the age of 16, he imagined chasing after a beam of light and that the thought experiment had played a memorable role in his development of special relativity. Famous as it is, it has proven difficult to understand just how the thought experiment delivers its results. It fails to generate serious problems for an ether based electrodynamics. I propose a new way to read it that fits it nicely into the stages of Einstein's discovery of special relativity. It shows the untenability of an "emission" theory of light, an approach to electrodynamic theory that Einstein considered seriously and rejected prior to his breakthrough of 1905.

The statistics for the eastern war are grim. more than three-million men died in the fighting, more than nine-million men were wounded, and every major country which participated lost its form of government.