Home›Open QuestionsCategoryOpen Questions10 entries. Click any to see everything it connects to.BrowseCompareCompare At A Past YearEnter a year to compare these entries as the atlas records them at that moment. Leave it empty for the present. A year before the common era is entered with a minus sign, so 44 BCE is minus 44.Show This YearSelect all 10Did Guglielmo Marconi know of Alexander Popov's 7 May 1895 coherer receiver demonstration before filing his own 1896 patent application, or did the two men arrive at similar designs independently from the same published coherer research?Open Questions3 linksDid Knowledge of Chinese and Korean Movable Type Reach Johannes Gutenberg Before His Independent Invention?Open Questions2 linksDoes priority for isolating metallic aluminum belong to Hans Christian Orsted, whose 1825 sample was first but impure and never fully confirmed, or to Friedrich Wohler, whose 1827 sample was purer and better documented?Open Questions2 linksDoes priority for vulcanization belong to Charles Goodyear, who discovered the sulfur-and-heat process in 1839, or Thomas Hancock, who filed the first patent on it, in Britain, in 1843?Open Questions2 linksDoes Su Song's 1092 water-driven astronomical clock tower count as the first mechanical clock, or does that title belong to the weight-driven verge-escapement clocks first attested in Europe in the 1280s?Open Questions2 linksShould sintering's origin be dated to its ancient craft use in fired ceramics and early sintered-metal artifacts, or to William Coolidge's 1909 patented process, the point it became a deliberately engineered industrial technique?Open Questions2 linksWas Garrett AiResearch's classified Central Air Data Computer chip set (1968-1970), Texas Instruments' 1971 single-chip CPU patent, or Intel's commercially released 4004 (1971) the first true microprocessor?Open Questions2 linksWhen did the Chinese magnetic compass move from a tool of divination and orientation to genuine sea navigation, and did the practice reach medieval Europe by transmission along existing trade routes or arise there independently?Open Questions2 linksWho Invented the WheelOpen Questions2 linksWho should be credited as radar's inventor: Christian Hulsmeyer's 1904 patent, Robert Watson-Watt's 1935 Daventry Experiment, or one of the other near-simultaneous 1930s national radar programs in Germany, France, the United States or the Soviet Union?Open Questions2 links