Who was the French professor that the Robert brothers built the world's first hydrogen balloon for?
Jacques Charles Jacques Alexandre César Charles (November 12, 1746 – April 7, 1823) was a French inventor, scientist, mathematician, and balloonist.
Richard Friend Sir Richard Henry Friend (born 18 January 1953) FRS FREng is Cavendish Professor of Physics at the University of Cambridge and Tan Chin Tuan Centennial Professor at the National University of Singapore. Friend's research concerns the physics and engineering of carbon-based semiconductors.