A full theory of eternal inflation came together in Carroll's mind in 2004, while he was attending a five - month workshop on cosmology at the University of California at Santa Barbara's famous Kavli Institute of Theoretical Physics with his student Jennifer Chen.
All of these universes are believed to come into existence through a process called eternalinflation, in which at least one universe continually expands at an incredible rate, while others form and grow within it like bubbles.