Two simple experiments that nobody understands. It seems completely impossible to explain these experiments physically and logically free of contradictions. What does it mean? Are they showing a constitution of reality - of light and matter - which is not recognizeable on principle? Or rather a simple failure of our old reality models (body, atom & wave)? In opposition to the most physicists Einstein saw this situation as a complete failure of our traditional physical models and pleaded for a search for a new physics, in which matter and light should be recognized as the same, as energetic field structures different only in their density. He must already have seen the failure of the body term of mechanics as the main reason of the quantum dilemma, but he could never find a new physical principle to prepare the field theory fitting to the experimental facts - and to the atomistic worldview. Nevertheless this principle must be very simple and seems to hide directly behind the double-slit.