with wire ropes structure (Ostankino Tower), Nikitin-Travush 4000 project (precursor to X-Seed 4000) Paul Gottlieb Nipkow (1860–1940), Germany – Nipkow disk Jun-ichi Nishizawa (1926–2018), Japan – Optical communication system, SIT/SITh (Static Induction Transistor/Thyristor), Laser diode, PIN diode Alfred Nobel (1833–1896), Sweden – dynamite Ludvig Nobel (1831–1888), Sweden/Russia – first successful oil tanker Emmy Noether (1882–1935), Germany, groundbreaking contributions to abstract algebra and theoretical physics; Noether's Theorem Jean-Antoine Nollet (1700–1770), France – Electroscope Wilhelm Normann (1870–1939), Germany – Hydrogenation of fats Carl Richard Nyberg (1858–1939), Sweden – the blowtorch O Aaron D. O'Connell (born 1981), U.S. – first Quantum machine Joseph John O'Connell (1861–1959), U.S. – number of inventions relating to telephony and electrical engineering Theophil Wilgodt Odhner (1845–1903), Sweden/Russia – the Odhner Arithmometer, a mechanical calculator Paul Offit (born 1951), U.S., along with Fred Clark and Stanley Plotkin, invented a pentavalent Rotavirus vaccine Jarkko Oikarinen (born 1967), Finland – Internet Relay Chat (IRC) Katsuhiko Okamoto (?–), Japan – Okamoto Cubes = modifications of Rubik's Cube Ransom Eli Olds (1864–1950), U.S. – Assembly line Lucien Olivier (1838–1883), Belgium or France / Russia – Russian salad (Olivier salad) Gerard K. O'Neill (1927–1992), U.S. – Storage ring (physics) J. Robert Oppenheimer (1904–1967), United States – Atomic bomb Hugh Orr (1715–1798), U.S. – machine for cleaning flax seed Hans Christian Ørsted (1777–1851), Denmark – electromagnetism, aluminium Elisha Otis (1811–1861), U.S. – safety system for elevators William Oughtred (1575–1660), UK – slide rule P Arogyaswami Paulraj (born 1944), India/U.S. – MIMO Antonio Pacinotti (1841–1912), Italy – Pacinotti dynamo Hilary Page (1904-1957), UK – Self-Locking Building Bricks, the predecessor of Lego Larry Page (born 1973), U.S. – with Sergey Brin invented Google web search engine William Painter (1838–1906), UK/U.S. – Crown cork, Bottle opener Salvatore Pais (born 1967), Romania/U.S. – an electromagnetic field generator to deflect asteroids away from the Earth, an inertial mass reduction device, a room-temperature superconductor, a gravitational wave generator, and a compact fusion reactor Alexey Pajitnov (born 1956), Russia/U.S. – Tetris Julio Palmaz (born 1945), Argentina – balloon-expandable, stent Helge Palmcrantz (1842–1880), Sweden – the multi-barrel, lever-actuated, machine gun Daniel David Palmer (1845–1913), Canada – chiropractic Luigi Palmieri (1807–1896), Italy – seismometer Frank Pantridge (1916–2004), Ireland – Portable defibrillator Georgios Papanikolaou (1883–1962), Greece / U.S. – Papanicolaou stain, Pap test = Pap smear Alice H. Parker (1895–1920), U.S. – central heating using natural gas furnace Philip M. Parker (born 1960), U.S. –