The first succesful daguerrotype of the Sun, reproduced below,
was made on 2 April 1845 by the French
physicists Louis Fizeau (1819-1896) and Léon Foucault (1819-1868)
(the two being perhaps better known for their
various pioneering measurements of the speed of light). The
exposure was 1/60 of a second. This image shows the umbra/penumbra
structure of sunspots, as well as limb darkening.
Reproduction of the first daguerrotype of the Sun. The original
image was a little over 12 centimeters in diameter.
Reproduced from G. De Vaucouleurs,
Astronomical Photography, MacMillan, 1961 [plate 1].
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| Pariser Pantheon, 1851: Foucaultsche Pendel sind schwere Gewichte, die an einem möglichst langen Seil befestigt sind. |
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FIGURE 1 (left) Foucault Pendulum at the North Pole. The plane of the pendulums swing stays fixed while the Earth turns beneath it. (right) Illustration of the original Foucault experiment from a 1851 newspaper.
