derived from experiment and observation rather than theory; "an empirical basis for an ethical theory"; "empirical laws"; "empirical data"; "an empirical treatment of a disease about which little is known"
the branch of quantum physics that accounts for matter at the atomic level; an extension of statistical mechanics based on quantum theory (especially the Pauli exclusion principle)
a noticeable deterioration in performance or quality; "the team went into a slump"; "a gradual slack in output"; "a drop-off in attendance"; "a falloff in quality"
fall heavily or suddenly; decline markedly; "The real estate market fell off"
fall or sink heavily; "He slumped onto the couch"; "My spirits sank"
discovered or determined by scientific observation; "variation in the ascertained flux depends on a number of factors"; "the discovered behavior norms"; "discovered differences in achievement"; "no explanation for the observed phenomena"