Almost weightless and able to pass through the densest materials with ease, neutrinos seem to defy the laws of nature. But these mysterious particles may hold the key to our deepest questions about the universe, says physicist Heinrich Päs. In The Perfect Wave , Päs serves as our fluent, deeply knowledgeable guide to a particle world that tests the boundaries of space, time, and human knowledge. The existence of the neutrino was first proposed in 1930, but decades passed before one was detected. Päs animates the philosophical and scientific developments that led to and have followed from this seminal discovery, ranging from familiar topics of relativity and quantum mechanics to more speculative theories about dark energy and supersymmetry. Many cutting-edge topics in neutrino research--conjectures about the origin of matter, extra-dimensional spacetime, and the possibility of time travel--remain unproven. But Päs describes the ambitious projects under way that may confirm them, including accelerator experiments at CERN and Fermilab, huge subterranean telescopes designed to detect high-energy neutrino radiation, and the Planck space observatory scheduled to investigate the role of neutrinos in cosmic evolution. As Päs's history of the neutrino illustrates, what is now established fact often sounded wildly implausible and unnatural when first proposed. The radical side of physics is both an exciting and an essential part of scientific progress, and The Perfect Wave renders it accessible to the interested reader.