artificial-intelligence-ai2Silicon Valley loves a new fad. To judge by the spate of fundraising by start-ups in recent weeks, it has found one in an idea that is more than half a century old: artificial intelligence. “This is the hot place to be at the moment,” says Stephen Purpura, whose own AI company, Context Relevant, has raised more than $44m since it was founded in 2012. By his reckoning, more than 170 start-ups have jumped on the AI bandwagon. The newcomers to AI believe that the technology has finally caught up with the hopes, bringing a heightened level of intelligence to computers. They promise a new way for humans to interact with machines — and for the machines to encroach on the world of humans in unexpected ways. More