Batteries may have existed 1000 or more year before Volta: see Wikipedia's History of the Battery. If this was the case, it's hard to see why such a useful technology disappeared for so long. Perhaps it was banned by religious forces claiming it was the work of the devil -- or a scientific threat to religion. More likely there was a huge patent dispute which completely halted the Progress of Science and useful Arts :-)
Drones are, in essence, flying autonomous vehicles. Pros and cons surrounding drones today might well foreshadow the debate over the development of self-driving cars. In the context of a strongly regulated aviation industry, "self-flying" drones pose a fresh challenge. How safe is it to fly drones in different environments? Should drones be required for visual line of sight – as are piloted airplanes? Join EE Times' Junko Yoshida as she moderates a panel of drone experts.