Replicate Universe

A journey into one of the greatest mysteries of modern science, this book explores the hidden world of dark matter—and the proposition that it may reside in a parallel "mirror" universe existing alongside our own.Astronomical observations have established that most of the matter in the universe is in an invisible form, known as dark matter. Serendipitously discovered by Fritz Zwicky in 1930, the existence of dark matter was confirmed by detailed observations of the speed of stars in galaxies by Kent Ford and Vera Rubin in the 1970s. In 2001, the explorer mission launched by NASA provided further confirmation and established that dark matter constitutes more than 80% of matter in the universe. It has since become clear that dark matter explains how galaxies formed from the uniformly expanding cosmic fluid as the universe evolved, thereby solving another major mystery of the cosmos.The question at the frontier of current research in cosmology and particle physics is this: what exactly is dark matter? Many high-sensitivity experiments have been carried out to answer this question, but so far they have been unsuccessful. This has led to speculation that dark matter may exist in an alternate universe, where particles experience different forces than we do and interact with familiar matter only through gravity. This would explain why laboratory detectors—built from the material of the visible world—have failed to find such matter. We call this alternate realm the "mirror universe" or "replicate universe". This universe supposedly coexists side by side with our own and contains identical copies of our universe's matter and forces. This daring idea was first proposed in 1956 by T D Lee and C N Yang and has since been elaborated and applied to dark matter physics. Focusing on lucid explanations instead of dense equations, this book introduces the fascinating concept of the "replicate universe" to a general audience and reveals its powerful implications for our understanding of the universe.