No longer were there green forests and high mountains—all that existed were millions of grains of sand, a vast deposit of bones and stones pulverized into dust… This sand box somehow doubled as an open grave—a grave that children cheerfully play in.

I should now like to prove the irreversibility of eternity by using a jejune experiment for proving entropy. Picture in your mind’s eye the sand box divided in half with black sand on one side and white sand on the other. We take a child and have him run hundreds of times clockwise in the box until the sand gets mixed and begins to turn grey; after that we have him run anti-clockwise, but the result will not be a restoration of the original division but a greater degree of greyness and an increase of entropy.

Robert Smithson, A Tour of the Monuments of Passaic, New Jersey (1967)

Entropy Machine (for Smithson), 2018, Drone quadcopter video, 3 minutes 33 seconds, Granville, New York