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Prepared and isolated from urine, it was the first element whose discovery date and discoverer are recorded. [53] Its name first appears in print in the work of Georg Kaspar Kirchmayer in 1676. Recognised as an element by Lavoisier. [1] 1 Hydrogen: 1671 R. Boyle: 1671 R. Boyle Robert Boyle produced it by reacting iron filings with dilute acid.
Period: period 3: Block ... Silicon is a chemical element; ... developed by American engineer Greenleaf Whittier Pickard in 1906. [37] In 1940, ...
The following dates are approximations. 700 BC: Pythagoras's theorem is discovered by Baudhayana in the Hindu Shulba Sutras in Upanishadic India. [18] However, Indian mathematics, especially North Indian mathematics, generally did not have a tradition of communicating proofs, and it is not fully certain that Baudhayana or Apastamba knew of a proof.
American engineer Edwin Howard Armstrong developed the Electronic oscillator: 1915: French physicist Paul Langevin and Russian engineer Constantin Chilowsky invented sonar: 1917: American engineer Alexander M. Nicholson invented the crystal oscillator: 1918: French physicist Henri Abraham and Eugene Bloch invented the multivibrator: 1919
January 1916, scientific journal: American Mineralogist, first issue. 1916, X-ray powder diffraction: "Peter Debye (1884–1966) – Paul Scherrer (1890–1969) powder method". 1919, founding of the Mineralogical Society of America (MSA). Georg Menzer (1897–1989) solves the first crystal structure of garnet (1925). [22]
The Lower Paleolithic period lasted over 3 million years, during which there many human-like species evolved including toward the end of this period, Homo sapiens.The original divergence between humans and chimpanzees occurred 13 (), however interbreeding continued until as recently as 4 Ma, with the first species clearly belonging to the human (and not chimpanzee) lineage being ...
During Berzelius' tenure, he is credited with revitalising the Academy and bringing it into a second golden era (the first being the astronomer Pehr Wilhelm Wargentin's period as secretary from 1749 to 1783). [13] He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1822. [14]
From the early 15th century to the early 17th century the Age of Discovery had, through Portuguese seafarers, and later, Spanish, Dutch, French and English, opened up southern Africa, the Americas (New World), Asia and Oceania to European eyes: Bartholomew Dias had sailed around the Cape of southern Africa in search of a trade route to India; Christopher Columbus, on four journeys across the ...