BBC 地平线：我们身处哪个宇宙

Imagineaworldwheredinosaursstillwalktheearth.AworldwheretheGermanswonWorldWarIIandyouarepresidentoftheUnitedStates.Imagineaworldwherethelawsofphysicsnolongerapplyandwhereinfinitecopiesofyouareplayingouteverystorylineofyourlife.ItsoundslikeaplotstolenstraightfromHollywood,butfarfromit.Thisisthemultiverse.Untilveryrecentlythewholeideaofthemultiversewasdismissedasafantasy,butnowthisstrangestofideasisatthecuttingedgeofscience.Andforagrowingnumberofscientists,themultiverseistheonlywaywewillevertrulymakesenseoftheworldwearein.Horizonasksthequestion:Domultipleuniversesexist?Andifso,whichoneareweactuallyin?