Quantum field theory captures the physics of elementary particles and their interactions, but some of its most interesting dynamical questions remain beyond the reach of conventional computation. I will present two recent quantum-computer calculations: parton distributions in the Schwinger model and thermalization in SU(2) lattice gauge fields. Together, they show how quantum simulation can open a new window on the structure and real-time evolution of quantum states, including the emergence of thermal behaviour from unitary dynamics.