Thousands of the world's foremost experts on artificial intelligence, worried that any technology they develop could be used to kill, vowed Wednesday to play no role in the creation of autonomous weapons. In a letter published online, 2,400 researchers in 36 countries joined 160 organizations in calling for a global ban on lethal autonomous weapons. Such systems pose a grave threat to humanity and have no place in the world, they argue. "We would really like to ensure that the overall impact of the technology is positive and not leading to a terrible arms race, or a dystopian future with robots flying around killing everybody," said Anthony Aguirre, who teaches physics at the University of California-Santa Cruz and signed the letter. Flying killer robots and weapons that think for themselves remain largely the stuff of science fiction, but advances in computer vision, image processing, and machine learning make them all but inevitable. The Pentagon recently released a national defense strategy calling for greater investment in artificial intelligence, which the Defense Department and think tanks like the Center for a New American Security consider the future of warfare. "Emerging technologies such as AI offer the potential to improve our ability to deter war and enhance the protection of civilians in the form of fewer civilian casualties and less collateral damage to civilian infrastructure," Pentagon spokesperson Michelle Baldanza said in a statement to CNNMoney.