Henry Quastler (November 11, 1908 – July 4, 1963) was an Austrian physician and radiologist who became a pioneer in the field of information theory applied to biology after emigrating to America. His work with Sidney Dancoff led to the publication of what is now commonly called Dancoff's Law. Life Quastler spent his early career in Vienna as a doctor. He received his medical degree in Vienna in 1932, focusing on histology and radiology. He met his wife, Gertrude Quastler, a milliner, when she came to him for treatment for tuberculosis. They married in 1933. The couple moved to Albania when King Zog asked for Quastler to train up radiologists. While there he also worked on malaria. Quastler's malaria expertise earned him a place on the International Health Board. As World War II approached in 1939, the couple left Albania and traveled to America. Within a year Quastler was working as a radiologist at New Rochelle Hospital in New York. In 1942, the Quastlers relocated to Urbana, Illinois, where Henry was employed as chief radiologist at Carle Hospital Clinic. While in Illinois, Gertrude Quastler studied art. She soon became a noted artist. Henry also painted as an amateur. According to his sister Johanna, the couple sometimes exhibited together. In 1949 Quastler gave up his medical practice to concentrate on science. Heinz von Foerster, who knew Quastler well, said that he became even more interested in radiation after the invention of the atomic bomb, which he considered "a horrifying human catastrophe". Foerster recalled Quastler pondering: "[Quastler asked] 'Can I now, as a working person, find out what damage has been done by the radiation of atomic bombs?'—that was his research question. Thus he started to conduct experiments on radiation damage in living organisms." ... Henry Quastler learned the basic concepts and formalisms of information theory with a speed that was almost unbelievable. And why? Because he needed this instrument urgently.". In the 1940s Quastler met Dancoff and collaborated with him to develop information theory in biology. They were interested in the problem of how to define the information content of a gene. After Dancoff's death, Quastler organized the symposium Information Theory in Biology, founded by him in 1952. Quastler soon became interested in how information theory could be used to understand the origin of life. In 1953 he edited Information Theory in Biology. He edited another collection of essays, Information Theory