Slipher Expanding Universe 2.04 Laird Thompson скачать в хорошем качестве

Slipher Expanding Universe 2.04 Laird Thompson

Conference on Origins of the Expanding Universe: 1912-1932 Sep 14-15, 2012 - Lowell Observatory Presentation 2.04 Laird Thompson Vesto Slipher and the development of nebular spectrographs While the earliest attempts to detect photographic spectra of galaxies — by Huggins (1888), Scheiner (1899), and Fath (1908)â€"showed only limited success, in the period from ~1906 to 1912 Slipher (1913) made great strides to improve both the signal-to-noise and the stability of his spectra. Only by doing so was Slipher able to measure the first galaxy Doppler shifts. I will briefly review from a technical perspective the steps involved: photographic sensitization, nebular spectrograph design, and consistent observing methods. By identifying fast spectrograph camera lenses as the key component in nebular spectrographs, Slipher pointed the way for Mt. Wilson astronomers Humason and Hubble to confirm the velocity-distance relationship in the period 1928 to 1931. For more, see http://www2.lowell.edu/workshops/slip... Presentation abstracts and slides at http://www2.lowell.edu/workshops/slip...