The never-ending debate over who built the first robot continues. Many believe that the drawings of Leonardo da Vinci are the first well-documented designs of what most would call a robot, but now Noel Sharkey, a computer scientist at the University of Sheffield in the UK, believes robots go back to Hero of Alexandria. Hero was a Greek mathematician and engineer who built many contraptions including vending machines, organs, and yes, a 3-wheeled cart driven by gravity used to automatically deliver props on a stage.