Reflections

Quantum physicist and author Jim al-Kahlili explains early on that the nine paradoxes of this book aren't really paradoxes because though they seem counterintuitive they can be resolved with careful reasoning, and then he proceeds to take the reader through those sometimes mindbending steps in ways I could actually grasp, though sometimes my understanding could only flicker in and out of existence like some kind of quantum particle. The oldest are Zeno's paradoxes about motion and the most recent is Fermi's paradox concerning the likelihood of life forms elsewhere in the universe. Thought provoking and mind teasing, the book is filled with helpful diagrams and since reading it I've been able to add wormholes, perpetual motion machines, multiverses, Heisenberg's Uncertainty Principle and parallel worlds to my conversational vocabulary.

The paradoxes investigate properties of the physical world with colorful mind experiments that feature demons who control trapdoors, cats that may be simultaneously dead and alive, pole vaulters who can run at the speed of light and grandfathers awaiting death at the hands of a time traveling grandchild. The questions explored range from childlike ponderings to philosophical inquiries. Why does it get dark at night? What proof is there for the "big bang"? Are we alone in the universe? Could you see your reflection in a mirror if you were traveling at the speed of light? Is the future determined? Do we have free will? Can a butterfly cause a hurricane? I was especially fascinated to read about how time travel might be possible, what changes occur during travel near the speed of light and when I can expect (or not) to meet an extraterrestrial life form.