Physics has two wonderful theories, relativity and quantum theory, but their marriage seems troublesome.
In this talk I will focus on one of the most striking quantum phenomenon, entanglement, which is considered to be, e.g., the essential ingredient in the better performance of the formidable quantum computers compared with classical ones or may become a way to detect and monitor cancer.
In particular, I will raise the question what happens if the entanglement is observed by a boosted observer? Obviously, here two very different ontologies meet and I will discuss how they come together from the quantum information theoretic point of view and which non-trivial and counter-intuitive effects arise due to geometry.