Time

About

Pictures are fixed, yet time runs through them. Claude Monet painted the facade of Rouen Cathedral more than 30 times in 1892–94, each canvas holding a different hour and weather, and Salvador Dalí's The Persistence of Memory (1931) lets pocket watches sag like melting cheese over a barren shore.

Other artists make duration the material. Nancy Holt's Sun Tunnels (1973–76), four concrete pipes in the Utah desert, frame the rising and setting sun at the solstices, and Robert Smithson's Spiral Jetty (1970) has disappeared beneath the Great Salt Lake and resurfaced, crusted with salt, as the water level changes. From 1965 until his death in 2011 Roman Opałka painted consecutive numbers in rows across his canvases, photographing his ageing face after each session. Ori Gersht uses high-speed cameras to freeze bouquets of flowers at the instant they explode. Look for sequences, clocks, erosion and the marks only time can make.