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.