Slipher Expanding Universe 2.02 John Peacock скачать в хорошем качестве

Slipher Expanding Universe 2.02 John Peacock

Conference on Origins of the Expanding Universe: 1912-1932 Sep 14-15, 2012 - Lowell Observatory Presentation 2.02 John Peacock Slipher, galaxies and cosmic velocity fields Slipher's 1917 paper was in many ways the culmination of his programme of nebular spectroscopy. Despite almost all his redshifts being positive, he did not announce the expansion of the universe, and it is interesting to ask why this was. The main reason is that the depth of his dataset was too shallow (although it was the same sample used by Hubble in 1929), and the velocity field is dominated on these scales by peculiar velocities. In this respect, Slipher's analysis and conclusions seem strikingly modern. In particular, he measures the motion of the Milky Way, and uses this in a marvelously subtle argument to show that nebulae are probably distant stellar systems. For more, see http://www2.lowell.edu/workshops/slip... Presentation abstracts and slides at http://www2.lowell.edu/workshops/slip...