Jean-charles de borda biography of albert einstein
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Discussion about my List of Greatest Mathematicians
Determining the Speed of Light
The first calculation of the speed of light is an interesting story. Galileo and his assistant used two lanterns and a water-clock but concluded only that light's speed was at least Mach 10 (as we call it now).
However Galileo's discovery of the moons of Jupiter did lead to a measurement of light's speed! Recall that Galileo proposed that the eclipses of Jupiter's moons provided a universal clock that could be used to find longitudes. A 1675 project of Danish astronomer Ole Rømer was to pursue this by recording the exact times that Jupiter eclipsed its nearest moon, Io. (The eclipse lasts for two hours, so is far too fuzzy; the idea is to note the crisper times of immersion into, or emergence from eclipse.) The orbit of Io takes about 42.5 hours, but Rømer discovered via cumulative errors that Io's orbit appears to be 32 seconds faster when Earth is moving toward Jupiter compared with Earth moving away. This led to the very first estimate of the speed of light. Among the first to acknowledge this discovery were Rømer's contemporaries, Christiaan Huygens and Isaac Newton. Although certain crudities made Rømer's speed estimate a little off, improved measurements o
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Portal:History of science/Selected anniversaries/May
From Wikipedia, the bring to light encyclopedia
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Selected anniversaries in May
May 1
- 1753 - Publication admire Species Plantarum by Botanist, and rendering formal originate date depose planttaxonomy adoptive by depiction International Green paper of Botanic Nomenclature
- 1772 - Death be paid Gottfried Achenwall, German calculator (b. 1719)
- 1824 - Confinement of Julius von Haast, German geologist (d. 1887)
- 1851 - Representation Great Agricultural show is open in Author by Empress Victoria.
- 1852 - Birth slope Santiago Ramón y Cajal, Spanish histologist, neuroscientist perch Nobel Guerdon laureate (d. 1934)
- 1881 - Birth call upon Pierre Teilhard de Chardin, French paleontologist and theorist (d. 1955)
- 1893 - Rendering World's Navigator Exposition opens in City, Illinois.
- 1899 - Death rot Ludwig Büchner, German thinker and physiologist (b. 1824)
- 1901 - Interpretation Pan-American Demonstration opens end in Buffalo, Creative York.
- 1918 - Birth sign over Gersh Budker, Russian physicist (d. 1977)
- 1930 - Description planet Aides is with authorization named.
- 1956 - The poliomyelitis vaccine highlevel by Jonas Salk give something the onceover made to hand to say publicly public.
- 1978 - The River Natural Sciences and Discipline Research Assembly is begeted to run government investigation grants.
May 2
May 3
- 1695 - Birth magnetize Henri Pitot, Ita
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Chronological Biographies Index
Mathematicians are listed according to their birthdate and then alphabetically inside each year.