On the 8.49am train through Silicon Valley, the tables are packed with young people glued to laptops, earbuds in, rattling out code. As the northern California hills scroll past, instructions flash up on screens from bosses: fix this bug; add new script. There is no time to enjoy the view. These commuters are foot soldiers in the global race towards artificial general intelligence – when AI systems become as or more capable than highly qualified humans. Here in the Bay Area of San Francisco, some of the world’s biggest companies are fighting it out to gain some kind of an advantage. And, in turn, they are competing with China.