As there seems to be some very general confusion, I'll try to make 1 or 2 points..
(a) Attributing the idea of relativity to Einstein alone is not correct. His achievement (at least for special relativity) was taking the existing mathematical ideas and unifying the concepts (there are still Lorentz transformations around named for the person who first brought them up). On a related note, Einstein did not get his Nobel prize for the theory of relativity ....
(b) Postulating a medium (ether or whatever) that electromagnetic waves need to propagate, borders on the absurd. I recommend reading about the Michelson-Morley experiments (which - I think - predate the theory of relativity by some time)...
(c) All theories in physics also this theory need to invoke some postulates. Postulates in this context being statements that can not (yet) be proven THEORETICALLY (mathematically), but can only be inferred from the fact that experimental observations fit with theoretical predictions derived from the postulates... The laws of thermodynamics are NOT such postulates, but can be derived from a SINGLE postulate, which states that "in equilibrium all accessible microstates of an enclosed system are occupied with the same probability". You just have to find a system in which this is not fulfilled, otherwise the laws derived from this stand...
(d) (I don't know if this has been stated) Perpetual motion machines are no problem for statistical physics (and for thermodynamics by inference), machines that run perpetually and produce energy in the process are, however, in violation of the laws of thermodynamics...
best regards