Physicist.
Max Karl Ernst Ludwig Planck, (April 23, 1858 – October 4, 1947) was a German theoretical physicist who originated quantum theory, which won him the Nobel Prize in Physics in 1918.
Planck made many contributions to theoretical physics, but his fame rests primarily on his role as originator of the quantum theory. This theory revolutionized human understanding of atomic and subatomic processes, just as Albert Einstein’s theory of relativity revolutionized the understanding of space and time. Together they constitute the fundamental theories of 20th-century physics. Both have led humanity to revise some of its most cherished philosophical beliefs, and have brought about industrial and military applications that affect many aspects of modern life.
Later in life, Planck's views on God were that of a deist. For example, six months before his death a rumour started that Planck had converted to Catholicism, but when questioned what had brought him to make this step, he declared that, although he had always been deeply religious, he did not believe "in a personal God, let alone a Christian God."
Sources:
1.) J. L. Heilbron (1986). The Dilemmas of an Upright Man: Max Planck and the Fortunes of German Science. Harvard University Press. p. 198. ISBN 9780674004399. "On the other side, Church spokesmen could scarcely become enthusiastic about Planck's deism, which omitted all reference to established religions and had no more doctrinal content than Einstein's Judaism. It seemed useful therefore to paint the lily, to improve the lesson of Planck's life for the use of proselytizers and to associate the deanthropomorphizer of science with a belief in a traditional Godhead."
2.) J. L. Heilbron (1986). The Dilemmas of an Upright Man: Max Planck and the Fortunes of German Science. Harvard University Press. p. 198. ISBN 9780674004399. "Six months before his death from a stroke on 4 October 1947, a rumor started that Planck had converted to Catholicism. An engineer applied to him for the reason that had brought him to such a step. The reply was not useful to missionaries. He had always been deeply religious, Planck said, but he did not believe in "a personal God, let alone a Christian God." A God without qualities, a religion without trappings, life without compartments, knowledge without divisions — in brief, a worldview without extremes — have little appeal to prophets and promoters."