▁similar ▁to ▁the ▁time ▁when ▁infl ation ▁occurred ▁( 1 0 − 3 2 ▁seconds ). ▁ ▁Me as uring ▁distance ▁in ▁a ▁metric ▁space ▁ ▁In ▁expand ing ▁space , ▁distance ▁is ▁a ▁dynamic ▁quantity ▁which ▁changes ▁with ▁time . ▁There ▁are ▁several ▁different ▁ways ▁of ▁defining ▁distance ▁in ▁cosm ology , ▁known ▁as ▁distance ▁measures , ▁but ▁a ▁common ▁method ▁used ▁amongst ▁modern ▁astronom ers ▁is ▁com oving ▁distance . ▁▁ ▁The ▁metric ▁only ▁defines ▁the ▁distance ▁between ▁nearby ▁( so - called ▁" local ") ▁points . ▁In ▁order ▁to ▁define ▁the ▁distance ▁between ▁arbitr arily ▁distant ▁points , ▁one ▁must ▁specify ▁both ▁the ▁points ▁and ▁a ▁specific ▁curve ▁( known ▁as ▁a ▁" sp ac etime ▁interval ") ▁connecting ▁them . ▁The ▁distance ▁between ▁the ▁points ▁can ▁then ▁be ▁found ▁by ▁finding ▁the ▁length ▁of ▁this ▁connecting ▁curve ▁through ▁the ▁three ▁dimensions ▁of ▁space . ▁Com oving ▁distance ▁defines ▁this ▁connecting ▁curve ▁to ▁be ▁a ▁curve ▁of ▁constant ▁cosm ological ▁time . ▁Operation ally , ▁com oving ▁distances ▁cannot ▁be ▁directly ▁measured ▁by ▁a ▁single ▁Earth - bound ▁observer . ▁To ▁determine ▁the ▁distance ▁of ▁distant ▁objects , ▁astronom ers ▁generally ▁measure ▁lum inos ity ▁of ▁standard ▁cand les , ▁or ▁the ▁red shift ▁factor ▁' z ' ▁of ▁distant ▁galaxies , ▁and ▁then ▁convert ▁these ▁measurements ▁into ▁distances ▁based ▁on ▁some ▁particular ▁model ▁of ▁spac etime , ▁such ▁as ▁the ▁L ambda - CD M ▁model . ▁It ▁is , ▁indeed , ▁by ▁making ▁such ▁observations ▁that ▁it