William G. Tifft was an astronomer at the

University of Arizona The University of Arizona (Arizona, U of A, UArizona, or UA) is a public land-grant research university in Tucson, Arizona. Founded in 1885 by the 13th Arizona Territorial Legislature, it was the first university in the Arizona Territory. T ...

. His main interests were in

galaxies A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...

, superclusters and

redshift quantization Redshift quantization, also referred to as redshift periodicity, redshift discretization, preferred redshifts and redshift-magnitude bands, is the hypothesis that the redshifts of cosmologically distant objects (in particular galaxies and quasars) ...

. He was influential in the development of the first

redshift survey In astronomy, a redshift survey is a survey of a section of the sky to measure the redshift of astronomical objects: usually galaxies, but sometimes other objects such as galaxy clusters or quasars. Using Hubble's law, the redshift can be used ...

s, and was an early proponent of crewed space astronomy, conducted at a proposed moon base for example. In retirement, he was a principal scientist with The Scientific Association for the Study of Time in Physics and Cosmology (SASTPC). He had an A.B. in Astronomy from Harvard University (1954), and Ph.D. in Astronomy from the California Institute of Technology (1958) where he wrote his dissertation on

photoelectric The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, and solid sta ...

photometry Photometry can refer to: * Photometry (optics), the science of measurement of visible light in terms of its perceived brightness to human vision * Photometry (astronomy), the measurement of the flux or intensity of an astronomical object's electro ...

Redshift quantization

Based on observations of nearby galaxies, Tifft proposed that the

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...

s of galaxies are quantized, or that they occur preferentially as multiples of a set number. These findings on

were originally published in 1976 and 1977 in the

Astrophysical Journal ''The Astrophysical Journal'', often abbreviated ''ApJ'' (pronounced "ap jay") in references and speech, is a peer-reviewed scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale and Jame ...

. The ideas were controversial when originally proposed; the editors of the Astrophysical Journal included a note in one of the papers stating that they could neither find errors within the analysis nor endorse the analysis. Subsequently, Tifft and Cocke put forward a theory to try to explain the quantization. Tifft's results were supported by Martin Croasdale, who claimed the effect to be statistically significant and the same over the whole sky, and later Napier and Guthrie. Since the initial publication of these results, Tifft's findings have been used by others, such as

Halton Arp Halton Christian "Chip" Arp (March 21, 1927 – December 28, 2013) was an American astronomer. He was known for his 1966 ''Atlas of Peculiar Galaxies'', which (it was later theorized) catalogues many examples of interacting and merging galaxie ...

, in making an alternative explanation to the

Big Bang Theory The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...

, which states that galaxies are redshifted because the universe is expanding. However, they have not found widespread support and are now dismissed by the majority of astronomers. Tifft himself, when interviewed for the popular science magazine Discover in 1993, stated that he was not necessarily claiming that the universe was not expanding.Dava Sobel,
Man stops universe, maybe - William Tifft believes the universe may not be expanding
, ''Discover'', April, 1993)

External links

Tifft Articles at the NASA ADS Database

References

{{DEFAULTSORT:Tifft, William G. 20th-century American astronomers American cosmologists University of Arizona faculty Harvard University alumni California Institute of Technology alumni Year of birth missing