Timeline of cosmic microwave background astronomy

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[edit] Timeline of cosmic microwave background astronomy

Thermal (non-microwave background) temperature predictions:

  • 1896 - Charles Edouard Guillaume estimates the "radiation of the stars" to be 5.6K.[1]
  • 1926 - Sir Arthur Eddington estimates the non-thermal radiation of starlight in the galaxy ".. by the formula E = σT4 the effective temperature corresponding to this density is 3.18º absolute .. black body"[2]
  • 1930s - Cosmologist Erich Regener calculates that the non-thermal spectrum of cosmic rays in the galaxy has an effective temperature of 2.8K
  • 1931 - Term microwave first used in print: "When trials with wavelengths as low as 18 cm. were made known, there was undisguised surprise+that the problem of the micro-wave had been solved so soon." Telegraph & Telephone Journal XVII. 179/1
  • 1934 - Richard Tolman shows that black-body radiation in an expanding universe cools but remains thermal
  • 1938 - Nobel Prize winner (1920) Walther Nernst reestimates the cosmic ray temperature as 0.75K
  • 1941 - Andrew McKellar uses the excitation of CN doublet lines to measure that the "effective temperature of space" is about 2.3 K
  • 1946 - Robert Dicke predicts ".. radiation from cosmic matter" at <20 K, but did not refer to background radiation [3]
  • 1946 - George Gamow calculates a temperature of 50 K (assuming a 3-billion year old Universe)[4], commenting it ".. is in reasonable agreement with the actual temperature of interstellar space", but does not mention background radiation.

Microwave background radiation predictions:

[edit] Future

  • 2008 The Clover Project will give an improved precision intermediate and high resolution map, and measure the B-mode polarization
  • 2009 The Planck (satellite) will give improved precision at all resolutions

[edit] Notes

  1. ^ Guillaume, C.-E., 1896, La Nature 24, series 2, p. 234, cited in "History of the 2.7 K Temperature Prior to Penzias and Wilson" (PDF)
  2. ^ Eddington, A., The Internal Constitution of the Stars, cited in "History of the 2.7 K Temperature Prior to Penzias and Wilson" (PDF)
  3. ^ Helge Kragh, Cosmology and Controversy: The Historical Development of Two Theories of the Universe (1999) ISBN 0-691-00546-X. "In 1946 Robert Dicke and coworkers at MIT tested equipment that could test a cosmic microwave background of intensity corresponding to about 20K in the microwave region. Howver, they did not refer to such a background, but only to 'radiation from cosmic matter'. Also this work was unreleated to cosmology, and is only mentioned because it suggests that by 1950 detection of the background radiation might have been technically possible, and also because of Dicke's later role in the discovery". See also Robert H. Dicke, Robert Beringer, Robert L. Kyhl, and A. B. Vane, "Atmospheric Absorption Measurements with a Microwave Radiometer" (1946) Phys. Rev. 70, 340–348
  4. ^ George Gamow, The Creation Of The Universe p.50 (Dover reprint of revised 1961 edition) ISBN 0-486-43868-6
  5. ^ Helge Kragh, Cosmology and Controversy: The Historical Development of Two Theories of the Universe (1999) ISBN 0-691-00546-X. "Alpher and Herman first calculated the present temperature of the decoupled primordial radiation in 1948, when they reported a value of 5 K. Although it was not mentioned either then or in later publications that the radiation is in the microwave region, this follows immediately from the temperature .. Alpher and Herman made it clear that what they had called "the temperature in the univerese" the previous year referred to a blackbody distributed background radiation quite different from sunliight".
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