On the concrete terrace David Medalla's Cloud Gates (1964-94) puffed and spluttered white foam into the grey London sky and the Hayward Gallery's architecture never seemed so resonant. It may embody the glum public conscience of an official Modern style, but the artists resurrected from the margins of Modernism in 'Force Fields' - an exhibition not only of Kinetic art but 'phases of the Kinetic' in the 20th century - sought to open the scientific mind to magic and to practice art as if it were a sensuous ritual. While Medalla's sculptures were blowing bubbles, reconstructions of his 1960s Mud Machine and Sand Machine drew abstract smears and circles nearby. Slop, slurp, thunk; an apparatus dragged mud out of a trough and spattered it on an illuminated screen. Medalla's drawings look like the existential gestures of an Action painter but are the twitches of a machine. His devices epitomise what made 'Force Fields' so fascinating: revelations of the ghost in the machine and the machine in the ghost.
The art recovered in 'Force Fields' dissolved distinctions between subject and object, human and natural forces, so that space, time and motion become at once the properties of the cosmos and the psyche. The classic Kinetic art of the post-War era appeared here as a supreme expression of Modern optimism. Mechanical gizmos, from Jean Tinguely's rusting automata to Takis' magnetic assemblages, embody an extreme enthusiasm for technological progress, yet the vision these artists share is anything but orthodox. Rather, they see science as an instrument of revolution, an opening up of inner and outer worlds of infinite possibility.
Kinetic art was neither a conventional Modern movement nor a refutation of Modernity, but a third way. The artists who experimented with movement in the 1950s and 60s were not satirising Action Painting, it just occasionally looks that way. Pol Bury's canvases, such as Surface Vibratile (1960), have wire bursting out of monochrome squares in literal versions of Abstract Expressionist gesture; Jesús Rafael Soto was similarly messing up the neat surface of the canvas in paintings of stunning vulgarity. But perhaps the most explicit re-inventions of Action Painting are not these European post-War space oddities but New Zealand filmmaker Len Lye's abstract films and three-dimensional constructions, displayed here to astonishing effect. Blade (1962-1976) is a grotesque assault on the stillness of a work of art. Warping, spinning, making sounds like someone playing the saw, it intrigues the eye, endangers the body and mocks the idea of art as a disembodied stilling of time. In these enthusiastically Modern works the evacuated flatness some saw as the goal of Modernism is replaced by all manner of sensual explorations of three-dimensional experience. Art is imagined as a scientific study of time, space and motion. It's all so rational, so progressive, but the results are crazy. And get crazier.
Gianni Colombo's installation Elastic Space (1967) strands the spectator in darkness. Only as your eyes become accustomed to the gloom do you realise what the loudly whirring motor fixed to the black tent you have entered is doing: manipulating a network of glow-in-the-dark wires, that encase you in an expanding and contracting model of a three-dimensional universe. What these artists assumed about Modernism - that it was both a scientific experiment and a psychic confession - was a continuation of pre-War avant-garde attitudes. Duchamp's Rotoreliefs and Alexander Calder's models of the universe were put side by side; Calder, one of the neglected figures of 20th-century art, acts as a corrective to over-refined readings of Duchamp's optical gimmicks. If Duchamp played with science, so did Calder, both doing something lunatic, illegitimate, and sanctioned neither by aesthetic nor scientific tradition. It is this lost space to which 'Force Fields' opens a path. Perhaps Calder's importance was considered marginal because there was something decorative or un-serious about his approach. That was true of Tinguely too, and in the age of the Modern art museum these figures are more dangerous than ever in their fusion of high art and low entertainment. 'Force Fields' could have had more Calder and Tinguely; perhaps in its determination to restore Kinetic art to the history of the 20th century, the exhibition was too desperate to link kinetic artists to today's litany of post-War greats - Manzoni, Fontana and, the show's least necessary inclusion, the overrated Henri Michaux.
But that's just a quibble. 'Force Fields' restores to art a lost legion of passionate maniacs. Perhaps most fantastic of all - because the least reducible to stylishness - is Takis' ludicrous, compelling Ballet Magnetique (Magnetic Ballet, 1963). What a brilliant, stupid idea to re-stage the story of Modern art as an experiment with magnets. In an art world defined by careers and biographies this exhibition retrieved figures who can never be turned into coherent encyclopedia entries; artists of such fugitive brilliance as John Latham, David Medalla, and Lygia Clark. The history uncovered here is as fragile as Clark's Breathe with Me (1966), which invites you to form a rubber tube into a circle and stretch it next to your ear, listening to the sound of air entering and leaving the gap between the tube's joined ends. The result is an art that breathes.