Entanglement

September 30, 2002
In his newest book, Aczel (Fermat's Last Theorem) discusses a great mystery in physics: the concept of entanglement in quantum physics. He begins by explaining that "entanglement" occurs when two subatomic particles are somehow connected—or "entangled"—with one another, so that when something happens to one particle, the same thing simultaneously happens to the other particle, even if it's miles away. However, this concept violates the theory of special relativity, since communication between two places cannot occur faster than the speed of light. Einstein knew that the mathematics of quantum theory predicted that this could happen, but he didn't believe it. In the last decade, researchers have shown in laboratory experiments that entanglement does indeed happen, and in one case it occurred over a distance of almost 10 miles. Aczel explores how a Star Trek
–like teleportation may be possible via entanglement (however, a particle's quantum state, not the entire particle, is teleported to its mate), though perhaps at the expense of demonstrating entanglement's more real-world applications to cryptography. General readers may need to skim over his technical explanations, whereas more advanced readers will be interested in only the last third of the book. While the book won't satisfy dedicated science buffs, it will be an accessible entry into this concept of quantum physics.