▁is ▁an ▁ill usion . ▁Cent uries ▁later , ▁Isaac ▁Newton ▁supported ▁the ▁idea ▁of ▁absolute ▁time , ▁while ▁his ▁contemporary ▁Gott fried ▁Wilhelm ▁Le ib n iz ▁maintained ▁that ▁time ▁is ▁only ▁a ▁relation ▁between ▁events ▁and ▁it ▁cannot ▁be ▁expressed ▁independently . ▁The ▁latter ▁approach ▁eventually ▁gave ▁rise ▁to ▁the ▁spac etime ▁of ▁relativ ity . ▁ ▁Pres ent ism ▁vs . ▁et ernal ism ▁ ▁Many ▁philosoph ers ▁have ▁argued ▁that ▁relativ ity ▁implies ▁et ernal ism , ▁the ▁idea ▁that ▁the ▁past ▁and ▁future ▁exist ▁in ▁a ▁real ▁sense , ▁not ▁only ▁as ▁changes ▁that ▁occurred ▁or ▁will ▁occur ▁to ▁the ▁present . ▁Phil os opher ▁of ▁science ▁Dean ▁Rick les ▁disag rees ▁with ▁some ▁qual ifications , ▁but ▁notes ▁that ▁" the ▁cons ensus ▁among ▁philosoph ers ▁seems ▁to ▁be ▁that ▁special ▁and ▁general ▁relativ ity ▁are ▁in compatible ▁with ▁present ism ." ▁Some ▁philosoph ers ▁view ▁time ▁as ▁a ▁dimension ▁equal ▁to ▁spatial ▁dimensions , ▁that ▁future ▁events ▁are ▁" al ready ▁there " ▁in ▁the ▁same ▁sense ▁different ▁places ▁exist , ▁and ▁that ▁there ▁is ▁no ▁objective ▁flow ▁of ▁time ; ▁however , ▁this ▁view ▁is ▁disput ed . ▁ ▁Pres ent ism ▁is ▁a ▁school ▁of ▁philosophy ▁that ▁holds ▁that ▁the ▁future ▁and ▁the ▁past ▁exist ▁only ▁as ▁changes ▁that ▁occurred ▁or ▁will ▁occur ▁to ▁the ▁present , ▁and ▁they ▁have ▁no ▁real ▁existence ▁of ▁their ▁own . ▁In ▁this ▁view , ▁time ▁travel ▁is ▁impossible ▁because ▁there ▁is ▁no ▁future ▁or ▁past ▁to ▁travel