Rivane Neuenschwander, 'Suspension Point', 2008, drilled holes, dust, installation view. Photo by Andy Keate Walking into Rivane Neuenschwander's Suspension Point, the South London Gallery's bright, spacious interior is obscured by gloom. Allowing your eyes to adjust to the murk, the reason becomes clear: a wooden mezzanine has been constructed at roughly the midway point of the gallery's height, covering the entire space, with the only illumination coming through a staircase that leads up to the......