The Pythagoreans first posited that everything in the universe was reducible to pure mathematics. To test this theory the Site Gallery has mounted a digital extravaganza that begins at Sheffield railway station, where a woman's voice can be heard wafting over the concourse, counting down from 31,000. This turns out to be a sound installation by Lucy Kimbell. Its title, Software That Outputs a Voice That Starts With a Very Large Number and Counts Down To a Very Small Number, tells you everything you need to know. One suspects that the passing commuters might pay it more attention were it not so easy to mistake for an announcement about the train delays.
Back at the gallery, thickets of looped wiring, digital readouts and electronic components create the kind of beauty only a telecommunications engineer can really appreciate. An insidious ringing emanates from Paul William Mulvihill's Simple Harmonic Motion, an executive toy that generates the harmony of the spheres by caressing the rim of a half-filled wine glass. Tony Kemplen proves that, with the aid of only nine domestic timers, you can rig up a system programmed to light up a neon sign reading "The End" to coincide with the projected demise of the universe in 1,000,000,000,000 years - assuming one can guarantee a stable electricity supply for that long.
The rest of the exhibition occurs in the dark. Tatsuo Miyajima's meditative room gives a sense of what life must be like inside a circuit board. Luke Jerram's Matrix demands submission to a dystopian photo-booth that brands a virtual Bridget Riley directly on your retina.
Gradually, the more serious purpose of the exhibition dawns. Numbers aren't necessarily beautiful, merely ubiquitous. You're reminded that binary code forms the basis of modern communication. One thinks of the stock exchange, the internet, the trails of noughts attached to Monet paintings at auction.
A triumph of alternative aesthetics, this is proof that the digital revolution is almost complete. Yet when they finally switch off the analogue art transmitters, is this is all we'll be left with?
Until August 11. Details: 0114-281 2077.
