After the success of the extraordinary Black On White, at the Barbican earlier this year, and the charming Eislermaterial, in Edinburgh in August, the latest theatre piece by Heiner Goebbels is a huge disappointment. Max Black is a one-man show, written for the superb actor André Wilms, and built around the life and writings of a bizarre Russian-American scientist. His 30s article on vagueness was the starting point for Goebbels's hour-long fictional monologue, incorporating texts by Wittgen-stein, Valéry and Lichtenberg.

Black is a scientist having problems imposing order and logic on the seeming chaos around him. His mind is as cluttered as his laboratory: just as he is obsessed with the flood of unrelated ideas that jostle in his mind, so his laboratory is a jumble of discarded technology - there's an upturned bicycle, a wind-up gramophone, an upright piano, stuffed birds and bottles of chemicals, which Black uses to concoct the fireworks that are another of his obsessions. But none of his musings gets farther than his experiments, so Goebbels's portrait is deliberately inconclusive. We watch a day unfolding like many others in Black's life, going nowhere, achieving nothing.

The problem with the piece is that as composer and director, Goebbels cannot make nothingness interesting. In his Black On White it was the act of making music that created the compelling drama, and Max Black is intended as the precise opposite of that, with the drama, the actor's gestures, movements and speech, creating the soundscape.

Everything on stage is wired for sound - contact microphones pick up the noise of every drawer being opened, every bottle cap being opened, while real-time computer systems transform and project the sounds, so that the whole show is underpinned by pulsing and ticking tones, which sometimes reach great climaxes. It's a technological tour de force, very slickly achieved. But the good ideas are spread too thinly, and the less original ones over-used. Even the fireworks - credited to the pyrotechnician Pierre-Alain Hubert - are a bit disappointing, though the line of flame that creeps along the floor and across Black's desk just before the end of the show is a neat trick. That's all, though: despite the heavyweight texts, this is a very fluffy piece of theatre

At the Lyric, Hammersmith, tonight (0181-741 2311)