170 x 240 mm
Soft cover, 376 pages, signed
Conception by Raphaël Dallaporta and Studio Kummer & Herrman, Utrecht
Postface by Denis Savoie, astronomer and science historian

-> special edition with print also available here

Since 2017, Raphaël Dallaporta has been carrying out at the Paris Observatory a verification of this astronomical phenomenon known since antiquity: by photographing every day at the same time the mark of the sun projected along the meridian line drawn in 1732 on the floor of the Cassini room, the artist verifies that the curve represented by these points of light does indeed form an 8 loop figure around the axis over the course of a year. This curve is the result of the equation of time. Through this daily practice at the Paris Observatory, Raphaël Dallaporta reminds us that the 24-hour standard only constitutes straight and uniform time, a necessary convention for the functioning of our activities. In other words, as Heraclitus recalls in his fragment: "The Sun is new every day".

Raphaël Dallaporta recounted this long-term experiment in his book Équation du temps with an afterword by astronomer and science historian Denis Savoie.