2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41262I discuss four big questions that can be importantly addressed using concepts from modern QCD. They concern the origin of mass, the feebleness of gravity, the uniqueness of physical laws, and the fate of matter when it is squeezed very hard.Four minor typos corrected; 19 pages; email correspondence to Frank Wilczek <wilczek@mit.edu>; talk given at a Symposium in Honor of Heisenberg's 100th birthday, December 6, 2001, Munich; to be published in the FestschriftHigh Energy Physics - PhenomenologyAstrophysicsHigh Energy Physics - Theorytext