Recherches sur le Spectre Solaire. [With:] Spectre normal du soleil. Atlas de six Planches

ÅNGSTRÖM, Anders Jonas

Edité par W. Schultz, Upsalla, 1868

A propos de cet article

A FOUNDING WORK OF SPECTROSCOPY. First edition, a very fine copy in unrestored original printed wrappers, and rare thus, of one of the founding works of spectroscopy in which Ångström demonstrated the presence of hydrogen and a number of other elements in the sun; the atlas contains his great map of the solar spectrum. Since the plates of the atlas were simply laid in to the printed wrappers (and not sewn), the wrappers were often lost or damaged; it is rare to find these wrappers present and in fine condition as in our copy. In his Nobel Prize lecture, Arthur Schawlow (who shared the 1981 prize for his contributions to the development of laser spectroscopy) wrote: "Fraunhofer had charted the dark lines in the spectrum of the Sun, and had measured their wavelengths. But it was Ångström who first identified some of these lines as corresponding to bright lines emitted by particular substances . Most importantly, he showed the red line of hydrogen." "After 1861 Ångström intensively studied the spectrum of the sun, noticing the presence of hydrogen in the solar atmosphere and confirming the probable existence there of a number of other elements. In 1868 he published the monumental Recherches sur le Spectre Solaire, which contained an atlas of the solar spectrum with measurements of the wavelengths of approximately a thousand lines determined by the use of diffraction gratings. Ångström expressed his results in units of one ten-millionth of a millimetre - a unit of length that has been named the Ångström unit in his honor. In order to have a precise basis for the new science of spectroscopy, accepted standards were needed . In 1861 Kirchhoff made a map of the solar spectrum and labeled lines with the corresponding scale readings of his own prismatic instrument. These rapidly became the almost universally accepted manner of designating spectral lines, but they were inconvenient because each observer had to correlate his own readings with those of the arbitrary Kirchhoff scale. Ångström's wavelength measurements provided a more precise and convenient reference and, after 1868, became a competing authoritative standard" (DSB). Spectroscopic studies were crucial to Max Planck's explanation of blackbody radiation, Albert Einstein's explanation of the photoelectric effect, and Niels Bohr's explanation of atomic structure. Spectra are used to detect, identify and quantify information about the chemical composition of substances in the laboratory, as well as in astronomy where they enable the determination of the chemical composition and physical properties of celestial objects. "By the time that Ångström began his studies on spectral analysis at Uppsala, a fair amount of information was known, more experimentally than theoretically, about the solar spectrum. Optics had become a subject of intensive study during the first half of the nineteenth century, but there was little interest in identifying the cause of the lines on the spectra and in appreciating their structural implications . no significant progress had been made in the eighteenth century since Newton's classic investigations on sunlight and his experiments with prisms and reflecting telescopes . Newton failed to note that the light from the sun is not perfectly homogeneous; instead it was [William Hyde] Wollaston (1766-1828) who first discovered this effect by observing the rays of sunlight admitted through a narrow slit in a window blind. Wollaston's initial observation of seven dark lines, followed by [Joseph von] Fraunhofer's work, which included a greater number of lines in the solar spectrum, lies at the root of all subsequent works, including that of Ångström. The studies of these pioneers had shown that whereas sunlight differed from ordinary white light in having a spectrum of dark lines, colored light differed from the same white light in having a spectrum in which bright lines could be seen. Ångström familiarized himself with all of this work ." (Reif-Acherman). "By th.

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Détails bibliographiques

• Titre: Recherches sur le Spectre Solaire. [With:] Spectre normal du soleil. Atlas de six Planches
• Éditeur: W. Schultz, Upsalla
• Date de parution: 1868
• Reliure: Soft cover
• Édition: First edition.
• Catalogues du vendeur:
  • Astronomy, Relativity Theory
  • Chemistry, Medicine, Biology