The rush of technology in the 20th century brought more advances than the 11th through 19th centuries combined. Automobiles and aircraft, television and radio, computers and global communications, medical imaging and the leap of humans beyond Earth's atmosphere -- all these were born from the creative spark and labor of scientists and engineers.

How can we ensure that technology is humane and not inane? Can nations mount an effective defense without having to shoot? When computer intelligence exceeds human intelligence, what will it mean to be human? If you could -uninvent- one technology,...