Vesto Melvin Slipher (/ˈslaɪfər/; November 11, 1875 – November 8, 1969) was an Americanastronomer who performed the first measurements of radial velocities for galaxies, providing the empirical basis for the expansion of the universe.
His brother Earl C. Slipher was also an astronomer and a director at the Lowell Observatory.
Slipher used spectroscopy to investigate the rotation periods of planets and the composition of planetary atmospheres. In 1912, he was the first to observe the shift of spectral lines of galaxies, making him the discoverer of galactic redshifts.
In 1914, Slipher also made the first discovery of the rotation of spiral galaxies.
He discovered the sodium layer in 1929. He was responsible for hiring Clyde Tombaugh and supervised the work that led to the discovery of Pluto in 1930.
Edwin Hubble is often incorrectly credited with discovering the redshift of galaxies; these measurements and their significance were understood before 1917 by James Edward Keeler (Lick & Allegheny), Vesto Melvin Slipher (Lowell), and William Wallace Campbell (Lick) at other observatories.
Combining his own measurements of galaxy distances with Vesto Slipher's measurements of the redshifts associated with the galaxies, Hubble and Milton Humason discovered a rough proportionality of the objects' distances with their redshifts. This redshift-distance correlation, nowadays termed Hubble's law, was formulated by Hubble and Humason in 1929 and became the basis for the modern model of the expanding universe.
^Way, M.J.; D. Hunter, eds. (2013). Origins of the Expanding Universe: 1912-1932. San Francisco: ASP Conference Series 471. Astronomical Society of the Pacific.
^Nussbaumer, Harry (2013). 'Slipher's redshifts as support for de Sitter's model and the discovery of the dynamic universe' In Origins of the Expanding Universe: 1912-1932. Astronomical Society of the Pacific. pp. 25–38.Physics ArXiv preprint
^O'Raifeartaigh, Cormac (2013). The Contribution of V.M. Slipher to the discovery of the expanding universe in 'Origins of the Expanding Universe'. Astronomical Society of the Pacific. pp. 49–62.Physics ArXiv preprint
^Slipher first reports on the making the first Doppler measurement on September 17, 1912 in The radial velocity of the Andromeda Nebula in the inaugural volume of the Lowell Observatory Bulletin, pp.2.56-2.57. In his report Slipher writes: "The magnitude of this velocity, which is the greatest hitherto observed, raises the question whether the velocity-like displacement might not be due to some other cause, but I believe we have at present no other interpretation for it." Three years later, Slipher wrote a review in the journal Popular Astronomy, Vol. 23, p. 21-24 Spectrographic Observations of Nebulae, in which he states, "The early discovery that the great Andromeda spiral had the quite exceptional velocity of - 300 km(/s) showed the means then available, capable of investigating not only the spectra of the spirals but their velocities as well." Slipher reported the velocities for 15 spiral nebula spread across the entire celestial sphere, all but three having observable "positive" (that is recessional) velocities.
^Slipher, Vesto (1914). "The detection of nebular rotation". Lowell Observatory Bulletin, 62.
This page is based on a Wikipedia article written by authors
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.