Speaker: Metod Saniga Title: Doily -- A Gem of the Quantum Universe Abstract: Among finite geometries relevant for the theory of quantum information, the unique triangle-free 15_3-configuration -- the doily -- has been recognized to play the foremost role. First, being isomorphic to a symplectic polar space, it underlies the commutation relations between the elements of the two-qubit Pauli group and provides us with simplest settings for observable proofs of quantum contextuality. Second, being isomorphic to a non-singular parabolic quadric, it also lies in the heart of a remarkable magic three-qubit Veldkamp line of form theories of gravity. Finally, being a generalized quadrangle, it enters in an essential way certain black-hole entropy formulas and the so-called black-hole--qubit correspondence. The talk will highlight the most essential features of the above-outlined doily-settings, pointing out also physical relevance of other distinguished configurations.