▁right ▁show ▁two ▁views ▁of ▁spac etime ▁diag rams ▁that ▁show ▁the ▁large - scale ▁geometry ▁of ▁the ▁universe ▁according ▁to ▁the ▁ Λ CD M ▁cosm ological ▁model . ▁Two ▁of ▁the ▁dimensions ▁of ▁space ▁are ▁omitted , ▁leaving ▁one ▁dimension ▁of ▁space ▁( the ▁dimension ▁that ▁grows ▁as ▁the ▁cone ▁gets ▁larger ) ▁and ▁one ▁of ▁time ▁( the ▁dimension ▁that ▁proceed s ▁" up " ▁the ▁cone ' s ▁surface ). ▁The ▁narrow ▁circular ▁end ▁of ▁the ▁diagram ▁corresponds ▁to ▁a ▁cosm ological ▁time ▁of ▁ 7 0 0 ▁million ▁years ▁after ▁the ▁big ▁b ang ▁while ▁the ▁wide ▁end ▁is ▁a ▁cosm ological ▁time ▁of ▁ 1 8 ▁billion ▁years , ▁where ▁one ▁can ▁see ▁the ▁beginning ▁of ▁the ▁acceler ating ▁expansion ▁as ▁a ▁s play ing ▁out ward ▁of ▁the ▁spac etime , ▁a ▁feature ▁which ▁eventually ▁domin ates ▁in ▁this ▁model . ▁The ▁pur ple ▁grid ▁lines ▁mark ▁off ▁cosm ological ▁time ▁at ▁intervals ▁of ▁one ▁billion ▁years ▁from ▁the ▁big ▁b ang . ▁The ▁cy an ▁grid ▁lines ▁mark ▁off ▁com oving ▁distance ▁at ▁intervals ▁of ▁one ▁billion ▁light ▁years ▁in ▁the ▁present ▁era ▁( less ▁in ▁the ▁past ▁and ▁more ▁in ▁the ▁future ). ▁Note ▁that ▁the ▁circular ▁cur ling ▁of ▁the ▁surface ▁is ▁an ▁artifact ▁of ▁the ▁embedding ▁with ▁no ▁physical ▁significance ▁and ▁is ▁done ▁purely ▁to ▁make ▁the ▁illustr ation ▁view able ; ▁space ▁does ▁not ▁actually ▁curl ▁around ▁on ▁itself . ▁( A ▁similar ▁effect ▁can ▁be ▁seen ▁in ▁the ▁tub ular