Our universe is expanding at an ever-accelerating rate — a phenomenon that all theories of cosmology agree upon but none can fully explain. Now, a new theoretical study offers an intriguing solution: Perhaps our universe is expanding because it keeps colliding with and absorbing "baby" parallel universes.
Studies of the cosmic microwave background, the afterglow of the Big Bang, have revealed that our universe is experiencing accelerated expansion. For this observation to fit with the main theory of cosmic evolution — called the Standard Cosmological Model — physicists assume that the universe is filled with an enigmatic substance dubbed dark energy that drives the expansion.
