Nicolas Steno (11 January 1638 – 25 November 1686) was a Danish pioneer in both anatomy and geology. In 1659, he decided not to accept anything simply written in a book, instead resolving to do research himself. The consequences of this self-study is that he is considered the father of geology and stratigraphy. He was responsible for the the recognition of geological strata, and the theory that successive layers of geological formations (strata) contained a fossil record of life in chronological order. He eventually became a tutor to the de Medici family and, ultimately, became a Bishop and a strong leader in the Catholic Counter-Reformation. He is largely unknown, despite his many great achievements, which may have been due to his religious zeal in a time that was moving away from reasoned science and towards observational science.
As always we thank this Saint of Science for his work understanding life and the life of the Earth itself. Thank you Nicolas Steno.