Gravitational waves detectors
I believe that besides the mathematical constructions our best hope to understand and ultimately detect multiverses (if they exist) is by gravitational waves detectors.
In string theory, for example, the graviton can pass though universes because it is a close...
Hawkings and Krauss paragraphs
"Because there is a law such as gravity, the universe can and will create itself from nothing. Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist. It is not necessary to invoke God to light the blue...