2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/164222We argue that a systems of tightly knotted, linked, or braided flux tubes will have a universal mass-energy spectrum, since the length of fixed radius flux tubes depend only on the topology of the configuration. We motivate the discussion with plasma physics examples, then concentrate on the model of glueballs as knotted QCD flux tubes. Other applications will also be discussed.10 pages, 1 table, 4 figuresHigh Energy Physics - Phenomenologytext