Robert H. Gray
In 2016, Gray published an article in "Scientific American" about the Fermi paradox, which claims that if extraterrestrials existed, we would see signs of them on Earth, because they would certainly colonize the galaxy by interstellar travel. Gray argues that the Fermi paradox, named after Nobel Prize-winning physicist Enrico Fermi, does not accurately represent Fermi's views. Gray states that Fermi questioned the feasibility of interstellar travel, but did not say definitively whether or not he thought extraterrestrials exist.
Existential risk from artificial general intelligence
Nick Bostrom was the first person to suggest that an artificial general intelligence might deliberately exterminate humankind, and invention of artificial general intelligence is the explanation for the Fermi paradox. Bostrom's 2014 book om the artificial general intelligence question stimulated discussion. By 2015, public figures such as physicists Stephen Hawking and Nobel laureate Frank Wilczek, computer scientists Stuart J. Russell and Roman Yampolskiy, In April 2016, "Nature" warned: "Machines and robots that outperform humans across the board could self-improve beyond our control — and their interests might not align with ours."