What are gluons and how are they related to quarks? Why can't we see what the universe looked like before it was 380,000 years old? What exactly is space-time and why is "empty" space anything but? If these questions make your head hurt and heart race, have no fear: Christophe Galfard, a theoretical physicist from Cambridge University and former graduate student under Stephen Hawking comes to the rescue with The Universe in Your Hand: A Journey Through Space, Time, and Beyond.
The Universe in Your Hand is a series of thought experiments, much like the kind Albert Einstein used to imagine the behavior of objects moving near the speed of light. In simple, conversational and often humorous prose, Galfard takes readers from an imagined vacation on a tropical beach and whisks them up into the heavens, all the way to the edge of the observable universe. The Universe in Your Hand is the ultimate layperson's guide to everything, at least as early 21st-century physics understands it, and even a bit beyond--the end of the book deals with the theoretical boundaries of modern knowledge, including string theory and dark matter/energy. It is a masterpiece of popular science writing. --Tobias Mutter, freelance reviewer