It is possible that Einstein had some character flaw because totally unnecessarily already after his Nobel prize and when he was more famous than any other physicist before him in 1927 he plagiarized 1926 paper of Oscar Klein that lead to the Kaluza-Klein theory. But he was caught and the editor of the journal forced Einstein to write a statement that everything he showed was done year earlier by Klein.I did not know that story when I wrote my book, but I am not surprised. Yes, Einstein had a character flaw where he avoided crediting anyone. As Peter says, the Einstein collected works acknowledge that Einstein knew of the Kaluza-Klein work, and deliberately omitted any citation.
Properly crediting Kaluza-Klein theory is tricky. It appears that mathematician H. Weyl clearly understood that you could get general relativity and Maxwell's equations from and appropriate curvature on a 5-dimensional manifold. One dimension is time, and one is electromagnetic phase. Surely others understood this also. However I cannot find where anyone wrote it down clearly until many decades later, where it uses a connection on a circle bundle over a spacetime.
Another example that was new to me was his refusal to credit Gerber for the Mercury precession formula. Einstein claimed to not know that Gerber published the formula before, but even said that he would not have cited Gerber even if he had known.
I mostly judge Einstein for his Physics, not his personal ethics. But it is sometimes hard to figure out what he rediscovered, and what he stole.
Peter also says:
When Einstein derived (did not show details) the superposition of velocities he stated that the operation constitute a mathematic group. Interestingly pretty much the same phrase was in Poincare 1905 paper. Somehow I have difficulty believing that Einstein would use such a cool and fairly modern at that time mathematical concept which obviously was natural for Poincare.Yes, I agree with that. At best, Einstein was saying that the one-dimensional set of transformations in one direction form a group, as there is no sign that he grasped the significance of all Lorentz transformations forming a group. He likely got the term "group" from Poincare's paper.
It is interesting that in many textbooks Michelson precedes STR that is present as explanation of Michelson but it never is stated that Einstein did not use or was aware of Michelson. What motivated Einstein work, which experiments?Historians have debated this, and I have my own theory. I say that Einstein was not directly influenced by any experiment.
Michelson-Morley and other experiments clearly influenced Lorentz's 1895 paper, and Poincare's work. The purpose of Einstein's 1905 paper is just to give an alternate derivation of Lorentz's formulas, and not to give an empirical argument. There was no reason to rely on any experiment directly.
Einstein's comments on this seem confusing, but I think he was simply saying that Michelson-Morley was important to the history of special relativity, but not to his own 1905 paper. Those things are true. They are not confusing if you understand that special relativity had a history before Einstein.