Question: where did the a Swiss astronomer work most of his life, who proposed  a class of hypothetical redshift mechanisms that was proposed as an alternative explanation for the redshift-distance relationship?
Sentence (from "Fritz Zwicky"): In 1933, Zwicky was the first to use the virial theorem to infer the existence of unseen dark matter, describing it as ""dunkle Materie "".
Relevant evidence: No