You understand everything known to be a scientific truth was once merely a hypothesis? See, just because you have no empirical data as yet, does not make reality not be reality. Einstein theorized about the existence of black holes long before they were empirically detected. Along with many other conjectures. In fact he had theories that weren’t empirically proven for 100 years.
Empirical data isn’t needed. Reality is as it is. Humans need not observe it. It still is. Understand?