A possible solution to Einstein’s problem of 1953: the velocity of a quantum particle in a box Antonio Feoli, Elmo Benedetto, Luca D’Errico and Antonella Lucia Iannella Eur. Phys. J. Plus, 140 1 (2025) 33 Published online: 14 January 2025 DOI: 10.1140/epjp/s13360-025-05969-y