Light is a nimble gymnast. It travels in many colors and frequencies. Its waves, whether long or short, can shift to be longer or shorter. Light waves change direction. They bounce. What light can’t do, on its own at least, is bend backward. In other words, it always refracts or reflects in a predictable, normal direction. Scientists seeking to make light waves do such unnatural gymnastics have failed to find any natural material that does the job. But in recent years, physicists and engineers have been experimenting with different “metamaterials,” engineered substances that inte... (p. 24)

Genes tell stories of disease, of health, of parentage, all recorded in the chemical composition of DNA. But to many biologists, one of the most exciting tales that sequences of DNA letters can tell is an evolutionary one. And since evolution on its largest scale—the shifting cast of organisms populating Earth over the past few billion years—happens over lengthy periods of time, some of the best stories may be locked in the DNA of species long buried and gone extinct. Sequencing the complete genome of a woolly mammoth that died 60,000 years ago or a Neandertal man who lived 40,000 ye... (p. 18)