The dictionary defines the universe as: All matter and energy, including Earth, the galaxies and all therein, and the contents of intergalactic space, regarded as a whole.
An article on CNN.com starts w/this sentence... The physical universe began not with a primordial Big Bang but with a monumental collision with another universe, a bold new theory suggests. Entire article:http://www.cnn.com/2001/TECH/space/04/13/big.bang.collision/index.html
So... all matter and energy collided with another all matter and energy. Cool.