1. After the success of quantum electrodynamics, Feynman turned to quantum gravity.

2. Why is the Brout-Englert-Higgs Mechanism needed: a quick revisition I The framework that combines principles of the Quantum Mechanics and the Special Relativity is the Quantum Field Theory (QFT) I Lagrangian (L) is used instead of Hamiltonian (H) I Physicists knew the Quantum Electrodynamics (QED) and tried to build a theory to explain the β-decay based on similar ideas