  Young's two-slit experiment constitutes the paradigm of quantum
complementarity. According to the complementarity principle, complementary
aspects of quantum systems cannot be measured at the same time by the same
experiment. This has been a long debate in quantum mechanics since its
inception. But, is this a true constraint? In 2011, an astounding realization
of this experiment showed that perhaps this is not the case and the boundaries
to our understanding of the quantum world are still far away.
