Yi Yake and his boyhood friends grew up in a farming village in central China, swinging sickles to harvest the family wheat crop. Yi got a job marketing computer games. His friend worked in a fireworks store. Today Yi drives a white BMW and, along with two childhood buddies, employs over 200 people in what is quickly becoming a boom industry in China -- artificial intelligence. Their company, located in a city near their parents' village in Henan province, provides an essential early service in the AI process, labeling images and videos to help make computers smarter.

Their company, located in a city near their parents' village in Henan province, provides an essential early service in the AI process, labeling images and videos to help make computers smarter. Before a self-driving car can learn to avoid hitting people or trees, it must learn what people and trees look like -- by digesting thousands of images labeled by thousands of humans. Demand for labeling is exploding in China as large tech companies, banks and others attempt to use AI to improve their products and services. Many of these companies are clustered in big cities like Beijing and Shanghai, but the lower-tech labeling business is spreading some of the new-tech money out to smaller towns, providing jobs beyond agriculture and manufacturing. The science is mired in controversy in China, where the ruling Communist Party is using AI to help it identify and track people in mass-surveillance programs, most prominently in the largely Muslim province of Xinjiang, according to Human Rights Watch.

On the chilly October day the New York City subway opened in 1904, the marvel of engineering and grit was greeted with horns, steam sirens and stations overrun by thousands of revelers. "Fast Trains in Tubes," blared one headline. On Wednesday, 114 years later in sun-swept Arizona, the launch of the 21st-century equivalent came in a blog post and an email invitation. Google offshoot Waymo announced it is launching the nation's first commercial self-driving taxi service in this and other Phoenix suburbs. The 24/7 service, dubbed Waymo One, will let customers summon self-driving minivans by a smartphone app, a la Uber or Lyft. Waymo's move comes after nearly a decade of development, more than a billion dollars in investment, and 10 million miles of testing on public roads.