I soon became convinced... that all the theorizing would be empty brain exercise and therefore a waste of time unless one first ascertained what the population of the universe really consists of.

88. He also went on to consider nuclear goblins which he proposed as "a body of nuclear density.

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. Fritz Zwicky (February 14 1898 – February 8 1974) was a Swiss astronomer.