其他宇宙存在吗？物理学说可能

ci-fi loves a multiverse. Everyone from Rick and Morty to Spider-Man has stepped through a portal and met their alter egos. Screenwriters often deploy this trope to incite interdimensional team-ups or showdowns. But some physicists like the idea of a multiverse for another reason: The existence of many unobserved realms could answer deep questions about our universe. Two of the most popular multiverse theories come from cosmology and quantum mechanics. Shortly after the Big Bang, our universe underwent a brief period of superfast expansion called infla- tion. During that growth spurt, tiny quantum fluctuations in the struc- ture of the universe got stretched out to huge proportions. …