Matter, Energy, and Investiture

VenDell's gloss on cosmere physics: everything is one of three essences — matter (formed of axi, the smallest known unit), energy (light, heat, electricity), and Investiture (the substance of the gods). The three are fundamentally the same and can be converted into one another. Burning a metal pulls Investiture out of the Spiritual Realm and uses it like energy; harmonium is Investiture made into matter; and what the Ladrian basement just demonstrated is matter being released back into energy. MB2:TLM:Ch 17