Of smaller size but which remains imposing and of different design, let us quote also the radio-telescope of Nançay of the CNRS installed in the Cher in France put in…
Radioastronomy
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22
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It has been known since the discovery of Heinrich Hertz in 1887 that radio waves are of the same nature as light waves. In particular they propagate in a vacuum…
Photography and its Limits
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9
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While the eye is sensitive only to the light perceived instantly, the silver medium (photo plate and films) that was still used until the 1980s can record the light received…
The Equatorial Mount
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6
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It is enough to have spent a few seconds on the eyepiece of a so-called azimuthal instrument, mounted on a tripod, to be aware of the sidereal movement which causes…
Solar Telescope
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30
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Around the world, about thirty observatories have dedicated at least one telescope to the study of the Sun. Given the atmospheric turbulence, it is almost impossible to use instruments over…
Technological Challenges
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7
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Since the manufacture of the 5 m diameter mirror of the Mount Palomar Observatory in 1939, because of their gross mass exceeding 40 tons, the mirrors of the large telescopes…
Modern Times
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10
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At the turn of the twentieth century, Lorentz understood the futility of mechanical support to explain the propagation of the electromagnetic field. He also discovered the theory of electrons. Meanwhile,…