The world of quantum physics is just magical.
This documentary manages to illustrate the mystery of the quntum world in a reasonably understandeble language! I am always amazed to see how physicists explain the world that can not even be seen with the best microscope in the world.
What is theory and what is reality? For a lay person like me most of these things are difficult to grasp, but anyway it is just magical to wander about what are we made of and how physicists struggle to find the answer to the question.
Double slit experiment is just mind-boggling and it proves how mysterious our world is and how we, as observers, affect what happens in the world by the mere act of observing it.
In Double slit experiment electrons behave as particles when observed (to be measured) and as waves when not observed, which is one of the greatest mysteries of quantum pshysics.