A collection of the brilliant physicist’s final papers will be published tomorrow in a book called Brief Answers to the Big Questions, but the U.K.’s Sunday Times revealed some excerpts early. In the papers, Hawking mused on the future of everything from artificial intelligence to aliens. But one of the most unsettling things Hawking talks about is the inevitability of the super rich being able to afford to edit their genes and the genes of their offspring through technologies like CRISPR to make them stronger, more intelligent, and more resistant to disease.

Hawking says these super-rich superhumans will lead to the decline of, well, us–poorer ordinary humans who can no longer compete. As Hawking wrote:

Once such superhumans appear, there are going to be significant political problems with the unimproved humans, who won’t be able to compete. Presumably, they will die out, or become unimportant. Instead, there will be a race of self-designing beings who are improving themselves at an ever-increasing rate. If the human race manages to redesign itself, it will probably spread out and colonise other planets and stars.

Oh, and if you want to be more depressed, Hawking warns about more upcoming threats, saying “in the future, AI could develop a will of its own, a will that is in conflict with ours,” and that in the next 1,000 years, major environmental calamity or a nuclear war will “cripple Earth.”