Robert Koch (1843–1910), Germany – method for culturing bacteria on solid media Willem Johan Kolff (1911–2009), Netherlands – artificial kidney hemodialysis machine Rudolf Kompfner (1909–1977), U.S. – Traveling-wave tube Konstantin Konstantinov (1817/1819–1871), Russia – device for measuring flight speed of projectiles, ballistic rocket pendulum, launch pad, rocket-making machine Sergei Korolev (1907–1966), USSR – first successful intercontinental ballistic missile (R-7 Semyorka), R-7 rocket family, Sputniks (including the first Earth-orbiting artificial satellite), Vostok program (including the first human spaceflight) Nikolai Korotkov (1874–1920), Russian Empire – auscultatory technique for blood pressure measurement Semyon Korsakov (1787–1853), Russian Empire – punched card for information storage Mikhail Koshkin (1898–1940), Russia – T-34 medium tank, the best and most produced tank of World War II Ognjeslav Kostović (1851–1916), Serbia/Russia – arborite (high-strength plywood, an early plastic) Gleb Kotelnikov (1872–1944), Russia – knapsack parachute, drogue parachute William Justin Kroll (1889–1973), Luxemburg/U.S. – Kroll process Alfred Krupa (1915-1989), Yugoslavia – the modern wheeled suitcase, a glass-bottom boat, the skis for use in walking on water, a folding canvas catamaran Aleksey Krylov (1863–1945), Russia – gyroscopic damping of ships Ivan Kulibin (1735–1818), Russia – egg-shaped clock, candle searchlight, elevator using screw mechanisms, a self-rolling carriage featuring a flywheel, brake, gear box, and bearing, an early optical telegraph Shen Kuo (1031–1095), China – improved gnomon, armillary sphere, clepsydra, and sighting tube Igor Kurchatov (1903–1960), Russia – first nuclear power plant, first nuclear reactors for submarines and surface ships Thomas E. Kurtz (born 1928), together with John G. Kemeny (1926–1992), U.S./Hungary – BASIC (programming language) Raymond Kurzweil (born 1948), Optical character recognition; flatbed scanner Ken Kutaragi (born 1950), Japan – PlayStation Stephanie Kwolek (1923–2014), U.S. – Kevlar John Howard Kyan (1774–1850), Ireland – The process of Kyanization used for wood preservation L Dmitry Lachinov (1842–1902), Russia – mercury pump, economizer for electricity consumption, electrical insulation tester, optical dynamometer, photometer, electrolyser René Laennec (1781–1826), France – stethoscope Georges Lakhovsky (1869–1942), Russia/U.S. – Multiple Wave Oscillator Hedy Lamarr (1914–2000), Austria and U.S. – Spread spectrum radio Edwin H. Land (1909–1991), U.S. – Polaroid polarizing filters and the Land Camera Samuel P. Langley (1834–1906), U.S. – bolometer Alexander Nikolayevich Lodygin (1847–1923), Russia – incandescent lamp Irving Langmuir (1851–1957), U.S. – gas filled incandescent light bulb, hydrogen welding Norm Larsen (1923–1970), U.S. – WD-40 Lewis Latimer (1848–1928), U.S. – improved carbon-filament light bulb Gustav de Laval (1845–1913), Sweden – invented the milk separator and the milking