<P> Planck regarded the scientist as a man of imagination and Christian faith . He said: "Both religion and science require a belief in God . For believers, God is in the beginning, and for physicists He is at the end of all considerations...To the former He is the foundation, to the latter, the crown of the edifice of every generalized world view". </P> <P> On the other hand, Planck wrote, "...' to believe' means' to recognize as a truth,' and the knowledge of nature, continually advancing on incontestably safe tracks, has made it utterly impossible for a person possessing some training in natural science to recognize as founded on truth the many reports of extraordinary occurrences contradicting the laws of nature, of miracles which are still commonly regarded as essential supports and confirmations of religious doctrines, and which formerly used to be accepted as facts pure and simple, without doubt or criticism . The belief in miracles must retreat step by step before relentlessly and reliably progressing science and we cannot doubt that sooner or later it must vanish completely ." </P> <P> 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 ." </P> <Ul> <Li> Planck, M. (1900a). "Über eine Verbesserung der Wienschen Spektralgleichung". Verhandlungen der Deutschen Physikalischen Gesellschaft. 2: 202--204 . Translated in ter Haar, D. (1967). "On an Improvement of Wien's Equation for the Spectrum". The Old Quantum Theory (PDF). Pergamon Press . pp. 79--81 . LCCN 66029628 . </Li> <Li> Planck, M. (1900b). "Zur Theorie des Gesetzes der Energieverteilung im Normalspectrum". Verhandlungen der Deutschen Physikalischen Gesellschaft. 2: 237 . Translated in ter Haar, D. (1967). "On the Theory of the Energy Distribution Law of the Normal Spectrum". The Old Quantum Theory (PDF). Pergamon Press . p. 82 . LCCN 66029628 . </Li> <Li> Planck, M. (1900c). "Entropie und Temperatur strahlender Wärme" (Entropy and Temperature of Radiant Heat). Annalen der Physik. 306 (4): 719--737 . Bibcode: 1900AnP...306...719P . doi: 10.1002 / andp. 19003060410 . </Li> <Li> Planck, M. (1900d). "Über irreversible Strahlungsvorgänge" (On Irreversible Radiation Processes). Annalen der Physik. 306 (1): 69--122 . Bibcode: 1900AnP...306...69P . doi: 10.1002 / andp. 19003060105 . </Li> <Li> Planck, M. (1901). "Über das Gesetz der Energieverteilung im Normalspektrum". Annalen der Physik. 309 (3): 553--563 . Bibcode: 1901AnP...309...553P . doi: 10.1002 / andp. 19013090310 . Translated in Ando, K. "On the Law of Distribution of Energy in the Normal Spectrum" (PDF). Archived from the original (PDF) on 6 October 2011 . Retrieved 13 October 2011 . </Li> <Li> Planck, M. (1903). Treatise on Thermodynamics . Ogg, A. (transl .). London: Longmans, Green & Co . OL 7246691M . </Li> <Li> Planck, M. (1906). Vorlesungen über die Theorie der Wärmestrahlung . Leipzig: J.A. Barth . LCCN 07004527 . </Li> <Li> Planck, M. (1914). The Theory of Heat Radiation . Masius, M. (transl .) (2nd ed .). P. Blakiston's Son & Co . OL 7154661M . </Li> <Li> Planck, M. (1915). Eight Lectures on Theoretical Physics . Wills, A.P. (transl .). Dover Publications . ISBN 0 - 486 - 69730 - 4 . </Li> <Li> Planck, M. (1943). "Zur Geschichte der Auffindung des physikalischen Wirkungsquantums". Naturwissenschaften. 31 (14--15): 153--159 . Bibcode: 1943NW...31...153P . doi: 10.1007 / BF01475738 . </Li> </Ul>

Who developed the quantum theory in 1900 and has a constant named for him