The Coriolis Effect

Four centuries of conflict between common sense and mathematics, Part I: A history to 1885


  • Anders Persson Swedish Meteorological and Hydrological Institute


One hundred years ago the German journal Annalen der Physik, the same 1905 volume in which Albert Einstein published his first five ground breaking articles, provided a forum for a debate between three physicists, A. Denizot, M.P. Rudzki and L. Tesa on the correct interpretation of the Coriolis force . The debate was complicated by many side issues, but the main problem was this: if the Foucault pendulum was oscillating, as it was often assumed, with its plane of swing fixed relative to the stars, why then was not the period the same, 23 hours and 56 minutes, everywhere on earth and not only at the poles? Instead it was 28 hours in Helsinki, 30 hours in Paris and 48 hours in Casablanca, i.e. the sidereal day divided by the sine of latitude. At the equator the period was infinite; there was no deflection. This could only mean that the plane of swing indeed was turning relative the stars. But how could then, as it was assumed, a “fictitious” inertial force be responsible for the turning? One hundred years later, Einstein’s five papers published in 1905 in Annalen der Physik are commonly used in undergraduate physics education whereas teachers and students, just like Denizot, Rudzki and Tesa, still struggle to come to terms with the Coriolis effect. This essay will sketch the complex and contradictory historical development of understanding the Coriolis Effect to about 1885. The continuing confusion since then is another story, but is undoubtedly related to our “Aristotelian” common sense. The reader’s attention is directed to the copious endnotes for additional details.