Sensational science fiction films like I, Robot may not be that far-fetched. “Stephen Hawking and a group of top physicists are sounding the alarm on artificial intelligence, writing in The Independent that success in creating AI could be ‘the biggest event in human history,’ but also ‘the last,’” CNBC reports.

Hawking writes that humans have already accomplished astounding feats, citing Google’s self-driving cars, Siri, Google Now, and Watson, the computer who won Jeopardy! (Watson even out-smarted Jeopardy! winner Ken Jenkins, who won the famous game show 74 times.) The physicists add, however, that achievements are only likely to become grander — and they could tangibly surpass human intelligence and ultimately human control. We already have “more sinister uses of AI like autonomous weapons that can choose their own targets,” CNBC ominously continues.

The introduction of robots into the public sphere is coming, and fast. “The amount of money that Google and other commercial companies will pour into robotics and artificial intelligence could at last take it truly into the commercial world where we actually do have smart robots roaming our streets,” Noel Sharkey, a robotics professor, reveals toThe Guardian. Violence is not the only thing to fear. Oxford University research warns that the commercialization of robots may cost 45% of Americans their jobs.

Hawking and his team advise the U.S. — and developers all over the world — to carefully research artificial intelligence and the implications of advancements before blindly creating. “One can imagine such technology outsmarting financial markets, out-inventing human researchers, out-manipulating human leaders, and developing weapons we cannot even understand,” Hawking concludes in The Independent.