Not since Newton's apple has there been a physics phenomenon as deliciously appealing to the masses as Frank Close's "Cosmic Onion". Widely embraced by scientists and laypersons alike, the book quickly became an international bestseller. Translated into seven languages, it propelled the author to become a worldwide celebrity as well as an inspiration to a generation of scientists. The book's title itself has entered popular usage as a metaphor for the layers that can be peeled away to understand the foundations of the physical world, from dimensions and galaxies, to atoms and quarks. 'Close is a lucid, reliable, and enthusiastic guide to the strange and wonderful microcosmic world that dwells deep within reality' - Frank Wilczek, Herman Feshbach Professor of Physics, MIT, 2004 Nobel Prize in Physics NEW Material. This title explains the principles behind the Hadron Collider as well as the potential it presents. It considers the recent development of the Electroweak Theory as a law of nature. It explores the mysteries uncovered and the ones that may be in store with regard to top and bottom quarks. Keeping still-pertinent contents from the original volume that caught the world's attention in 1983, this fresh edition of the Cosmic Onion includes extensive new material to reflect new views of the universe. Providing explanations that explore the foundations of 21st Century science and future directions, this work offers ready access and unique perspectives to more typical topics such as the forces of nature, atoms, the nucleus, and nuclear particles. It also travels down paths that only a true pioneer and educator can venture, such as a discussion of what Professor Close refers to as the Eightfold Way including the findings, surprises, and new questions emerging from the latest work with accelerators.