Complex sentence: William G. Tifft is Emeritus Professor/Astronomer at the University of Arizona, whose main interests are in galaxies, superclusters and what Tifft calls redshift problems (see Redshift quantization).
Split into simpler sentences: 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).