"The Quantum Zoo: A Tourist's Guide to the Neverending Universe" by Marcus Chown (Joseph Henry Press, 2006) is deceptively titled. Only half of it is about quantum physics. The second half is about macro physics: relativity and the space-time continuum. "A Review of Twentieth-Century Physics" would have been a more accurate title, but less appealing.
Chown is an excellent science writer. He puts one word in front of another with grace and wit and marches us through a century of physics with amusing anecdotes and without a whiff of calculus. He does not insult us - his writing is clear and simple without being condescending.
Modern physics really is a zoo: There are many types of particles and no way to contain them all in one "pen" - that is, no way to explain them in one theory.
Chown guides us through the basics of quantum physics, the physics of the extremely small particles that exist in discrete chunks (quanta) and combine to make everything in the universe.
He points out that matter is mostly empty space. If all the empty space were squeezed out of the human race, the remaining matter would be the size of a sugar cube. But then, in a final chapter he mentions that now physicists are thinking there is something in "empty" space.
"In fact, it is fair to say that the discovery that light comes in discrete chunks, or quanta, was the single most shocking discovery in the history of science," Chown writes.
He deals with unpredictability: "The whole Universe is founded on random chance. So upset was Einstein by this idea that he stuck out his lip and declared: 'God does not play dice with the Universe!' The trouble is, He does. As British physicist Stephen Hawking has wryly pointed out: 'Not only does God play dice with the Universe, he throws the dice where we cannot see them.'"
In chapter three, Chown discusses qubits. "In a quantum computer the basic elements - which may be single atoms - can be in a superposition of states. In other words, they can represent a zero and a one simultaneously. To distinguish them from normal bits, physicists call such schizophrenic entities quantum bits, or qubits." This chapter should attract anyone interested in the future of computing, even if only from an investment angle.
Chown doesn't shirk from taking the reader through multiple realities. He explains interference as the bridge between separate universes and decoherence as the mechanism for bringing it back together.
He writes: "Decoherence, the enemy of those struggling to build quantum computers, is also their greatest friend. It is because of decoherence, after all, that the giant superposition of a quantum computer with all its mutually interfering strands is finally destroyed. It is only by being destroyed - reduced to a single state representing a single answer - that anything useful comes out of such a machine. The world of the quantum is indeed a paradoxical one!"
Chown covers "spooky action at a distance" and the currently accepted plausibility of teleportation.
"There is a ghostly web of quantum connections crisscrossing the Universe and coupling you and me to every last bit of matter in the most distant galaxy. We live in a telepathic universe. What this actually means physicists have not yet figured out."
Walking through the quantum zoo, Chown shows us only the traditional exhibits. For bosons, he covers photons in depth and mentions gluons, but he ignores the more recently discovered bosons. For fermions, he discusses only the well-known electrons, protons and neutrons, ignoring all the creepy new little buggers, and completely failing to even mention quarks.
After only 83 pages on quanta, the book jumps to the big picture: Einstein's relativity. Again, Chown conveys extremely complex ideas with relative simplicity and mentions the multitude of questions unanswerable by current theories.
The book is short and contains a comprehensive glossary. It is as interesting as a trip to the zoo, and you get a bonus view-from-far-above.
"The Quantum Zoo" is available in the Friends of the Los Altos Libraries Bestseller Collection at the Los Altos main library, 13 S. San Antonio Road.