William G. Tifft
William G. Tifft is Emeritus Professor/Astronomer at the University of Arizona. His main interests are in galaxies, superclusters and what Tifft calls redshift problems (see redshift quantization). He was influential in the development of the first redshift surveys  and was an early proponent of manned space astronomy, conducted at a proposed moon base for example. In retirement, he is a principal scientist with The Scientific Association for the Study of Time in Physics and Cosmology (SASTPC).
He has 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 photometry, a copy of which is available online.
Based on observations of nearby galaxies, Tifft has put forward the idea that the redshifts of galaxies are quantized, or that they occur preferentially as multiples of a set number. These findings on redshift quantization were originally published in 1976 and 1977 in the Astrophysical Journal. 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 have been largely replicated by Croasdale and later Napier and Guthrie. Croasdale did a comprehensive analysis of the statistical significance and confirmed the special frame in which quantization is found to be the same over the whole sky. Since the initial publication of these results, Tifft's findings have been used by others, such as Halton Arp, in making an alternative explanation to the Big Bang Theory, which states that galaxies are redshifted because the universe is expanding. However, 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.
- Clicking on this link does a search for all articles by Tifft at the Smithsonian/NASA Astrophysics Data System. The full text of the articles is available in some cases.
- William G. Tifft's Personal Web page at the U. Arizona
- W. G. Tifft (1976). "Discrete states of redshift and galaxy dynamics. I - Internal motions in single galaxies". Astrophysical Journal. 206: 38–56. Bibcode:1976ApJ...206...38T. doi:10.1086/154354.
- W. G. Tifft (1977). "Discrete states of redshift and galaxy dynamics. II - Systems of galaxies". Astrophysical Journal. 211: 31–46. Bibcode:1977ApJ...211...31T. doi:10.1086/154901.
- W. G. Tifft (1977). "Discrete states of redshift and Galaxy dynamics. III - Abnormal galaxies and stars". Astrophysical Journal. 211: 377–391. Bibcode:1977ApJ...211..377T. doi:10.1086/154943.
- Martin R. Croasdale (1989). "Periodicity in Galaxy Redshifts". Astrophysical Journal. 345: 72–83. Bibcode:1989ApJ...345...72C. doi:10.1086/167882.
- W. M. Napier & B. N. G. Guthrie (1997). "Quantized Redshifts: A Status Report" (PDF). Journal of Astrophysics and Astronomy. 18 (4): 455–463. Bibcode:1997JApA...18..455N. doi:10.1007/BF02709337.
- H. Arp (1986). "A corrected velocity for the local standard of rest by fitting to the mean redshift of local group galaxies". Astronomy and Astrophysics. 156: 207–212. Bibcode:1986A&A...156..207A.
- H. Arp (1987). "Additional members of the Local Group of galaxies and quantized redshifts within the two nearest groups". Journal of Astrophysics and Astronomy. 8 (3): 241–255. Bibcode:1987JApA....8..241A. doi:10.1007/BF02715046.
- Dava Sobel, "Man stops universe, maybe - William Tifft believes the universe may not be expanding", Discover, April, 1993)