A revolutionary new account of our universe’s creation—and a breathtaking exploration of the landscape from which we sprang—from one of the world’s most celebrated cosmologists What came before the Big Bang, and what exists outside of the universe it created? Until recently, scientists could only guess at what lay past the edge of space-time. However, as pioneering theoretical physicist Laura Mersini-Houghton explains, new scientific tools are now giving us the ability to peer beyond the limits of our universe and to test our theories about what is there. And what we are finding is upending everything we thought we knew about the cosmos and our place in it. Mersini-Houghton is no stranger to boundaries—or to pushing through them. As a child growing up in Communist Albania, she discovered a universe beyond her walled-off world through the study of math and science, and through music. As a female cosmologist in a male-dominated field, she transcended the limits that society and her profession tried to place on her. And as a trailblazing researcher, she helped to revolutionize the study of our universe by revealing that, far from living in a cosmic Albania, with a world that ends at its borders, we are part of a larger family of universes—a multiverse—that holds wonders we are only beginning to unlock. Mersini-Houghton’s groundbreaking research suggests that we sit in a quantum landscape whose peaks and valleys hide a multitude of other universes, and even hold the secret to the origins of existence itself. Recent evidence has revealed the signatures of such sibling universes in our own night sky, confirming Mersini-Houghton’s theoretical work and offering humbling evidence that our universe is just one member of an unending cosmic family. The incredible scientific saga of one woman’s mind-expanding journey through the multiverse, Before the Big Bang will reshape our understanding of humanity’s place in the unfathomable vastness of the cosmos.