Infinite Universes

. Scientists can't be surewhat the shape ofspace-time is, butmost
likely, it'sflat (as opposed to spherical orevendonut-shape) and
stretches out infinitely. But ifspace-time goes on forever, then it must
start repeating at somepoint,because there are afinitenumber of ways
particles can be arranged inspace andtime.So if youlook far enough, you
would encounter another version of you — in fact, infinite versions ofyou.
Some of thesetwins will be doing exactlywhat you're doing rightnow,
while others willhave worn adifferent sweater this morning, and still
others willhavemade vastlydifferent career andlife choices.Because the
observableuniverseextends only as far aslighthas had a chance to get in
the 13.7 billion years since the Big Bang (that would be 13.7 billion
light-years), thespace-timebeyond thatdistance can be consideredto be
its own separateuniverse. In this way, a multitude ofuniverses exists
next toeach other in agiant patchwork quilt ofuniverses. [Visualizations
of Infinity: A Gallery]