Born in 1923 . Cooper served in the US Navy before taking a degree in Electrical Engineering at Illinois Institute of Technology. His first mobile phone weighed about 1 kilogram or 2.2 pounds. He tested it by calling a rival scientist to announce his success . The Motorola DynaTAC had twenty large buttons, a long rubber antenna and talk time of just thirty minutes , before needing to be recharged for 10 hours.