Since 1851, Foucault’s pendulum has hung in the Panthéon in Paris. It is a scientific device that demonstrates the Earth’s rotation. In 2022 artist Anne Veronica Janssens created an installation inspired by the swinging pendulum, 23:56:04. On the floor of the Panthéon, beneath the soaring dome ceiling, Janssens installed a round mirror, reflecting the architectural surrounds, and most notably the movement of the pendulum. The seemingly infinite reflection creates a submersive effect for the viewer, accentuating the hypnotic swing of the pendulum. Janssens’ artwork often deals with the fleetingness of experience and change, engaging the individual’s perception of the world and their body, mostly using light or glass and the optical effects as a medium.

The short video shows the installation of the site-specific artwork, and features Janssens’ description of the piece: "Enigmatic at first glance, 23:56:04 maintains a relationship to the celestial while being specifically linked to the arch of the Panthéon. 23:56:04 corresponds to the sidereal day, i.e. the length of time it takes the Earth to rotate once around itself before repositioning itself in relation to fixed stars. Its rotation was first revealed to the general public in the Panthéon in 1851, when Léon Foucault demonstrated its movement with the help of the pendulum."