7.75x9.5 B&W vintage photograph with a 1.5x.5 cut signature affixed to the lower left portion signed by Fritz Zwicky in fountain pen ink. Waviness and light scattered creasing, otherwise, in good condition.(1898-1974) Fritz Zwicky was a Swiss astronomer. He worked most of his life at the California Institute of Technology in the United States of America, where he made many important contributions in theoretical and observational astronomy. In 1933, Zwicky was the first to use the virial theorem to postulate the existence of unseen dark matter, describing it as "dunkle Materie".This lot came from the Jim Wiggins collection we purchased in July 2022. Jim Wiggins accumulated the most unique and valuable autograph collection over a period of 70-plus years. He obtained his collection either in person or by writing to persons of fame and notoriety. Comes with a full Letter of Authenticity from Todd Mueller Authentics.