Notes of a protein crystallographer: the legacy of J.-B. J. Fourier – crystallography, time and beyond

The importance of the Fourier transform as a fundamental tool for crystallo­graphy is well known in the field. However, the complete legacy of Jean-Baptiste Joseph Fourier (1768–1830) as a pioneer Egyptologist and premier mathematician and physicist of his time, and the implications of his work in other scientific fields, is less well known. Significantly, his theoretical and experimental work on phenomena related to the transmission of heat founded the mathematical study of irreversible phenomena and introduced the flow of time in physico-chemical processes and geology, with its implications for biological evolution. Fourier’s insights are discussed in contrast to the prevalent notion of reversible dynamic time in the early 20th century, which was dominated by Albert Einstein’s (1875–1953) theory of general relativity versus the philosophical notion of durée proposed by the French philosopher Henri-Louis Bergson (1859–1941). The current status of the mathematical description of irreversible processes by Ilya Romanovich Prigogine (1917–2003) is briefly discussed as part of the enduring legacy of the pioneering work of J.-B. J. Fourier, first established nearly two centuries ago, in numerous scientific endeavors.