Rock builds custom single-molecule fluorescence microscopes and optical tweezers to directly watch individual myosin motors move along the actin cytoskeleton in vitro and in living cells, quantifying motor stoichiometry, force generation, and navigation rules that organize cell shape and motility. Where NV-ensemble quantum sensors read out spin ensembles magnetically at pT/sqrt(Hz) sensitivity via DEER/NMR/T1 protocols, Rock's approach achieves single-fluorophore and single-motor mechanical/positional resolution using all-optical single-molecule methods.