Devised by observing a lathe demonstrating an unexpected but explainable gyroscopic effect, physicist Lรฉon Foucault first constructed his eponymous pendulum in the basement of his home on this day in 1851, bringing the experiment to the public a month later at the Meridian of the Paris Observatory. Allowing observers to conclude from the change in the plane of oscillation of a heavy weight over time the rotation of the Earth, and showing that at latitudes other than the equator the displacement of each cycle (best viewed on a very big set up) progresses relative to the turning of the Earth throughout the diurnal period. Though a long established fact that the Earth revolved, Foucault’s experiment was proof easily attainable and not necessitating watching for the minute movements of the stars and planets, rather elegantly showing that the Earth moves beneath the fixed and motionless pivot point. Such demonstrations have become popular installations at universities and museums around the world—see one in action here from a dedicated live webcam.
synchronoptica
one year ago: assorted links worth revisiting (with synchronoptica) plus Jim Henson’s custom car
seven years ago: Memento Mori, deep dreaming, Communist era interiors plus Trump’s minders
eight years ago: saccadic masking, book-culling algorithms, more links to enjoy plus literary-inspired resolutions
nine years ago: even more links
ten years ago: the last man on the Moon plus food pyramids and fad-diets