> "where is proof of causation"

No such thing as a proof in physics (proofs are for math). Instead, what is done is that one model is compared to another. For example, there is no proof that lunisolar gravitational forcing causes tidal cycles, only that the evidence showing consistency of orbital periods with sea level gauge measurements point to Laplace's Tidal Equations as the "best" model.
https://en.wikipedia.org/wiki/Theory_of_tides#Laplace's_tidal_equations