Michael Faraday lecturing at the Royal Institution, London, 1835 (20th century). Artist: Unknown
Michael Faraday lecturing at the Royal Institution, London, 1835 (20th century). Faraday (1791-1867) was one of the greatest scientists of the 19th century. His most significant contribution was the Experimental Researches on Electricity which was published over 40 years, where he described his discoveries, including the laws of electromagnetic induction (1831) and the laws of electrolysis (1833). He also discovered the principles of the electric motor and dynamo. Faraday founded the famous Friday evening discourse and children's Christmas lectures at the Royal Institution, both of which are still given today.
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Hermann Oberth, German rocket pioneer
Professor Hermann Oberth (1894-1989), German rocket pioneer, in Redstone Arsenal, USA, 1956. Oberth envisioned the idea of a "recoil rocket" which propelled itself by expelling exhaust gases. He developed this idea, considering how velocity was dependant upon the ratio of rocket mass to propellant and eventually concluded that space flight could be best achieved through multi-stage rockets. His doctoral thesis of 1922 on rocketry was rejected, but his work later became recognised as pioneering. Werner von Braun studied under him, and both were later instrumental in the development of the Nazi's V2 rocket, before continuing their work in the United States after the war.
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