How Many Universes Are There?
M.I.T. physicist Alan Guth has suggested that new universes—known as "pocket universes"— are constantly being created, but they cannot be seen from our universe.
Modern cosmology theory holds that our universe may be just one in a vast collection of universes known as the multiverse. In this view, “nature gets a lot of tries—the universe is an experiment that’s repeated over and over again, each time with slightly different physical laws, or even vastly different physical laws,” says Jaffe. Some of these universes would collapse instants after forming; in others, the forces between particles would be so weak they could not give rise to atoms or molecules.
