The experiment by Alain Aspect et al is interesting - they were testing the arrival at detectors separated by distance, of two photons produced by the same atom & they found contradictions to what should be seen if the universe is causal. That is, leaving out the lengthy path of logic & evidence, that there is apparently no objective reality out there; it is all based on observation.
I've seen other works that talk about this that seem to explain things but hadn't run across an actual experiment to show it.
For those interested in the science...
try here!