Colin Langridge In Memory 2002, Tasmanian oak and stainless steel, 150 x 50 x 50cm.

I must lay my cards on the table: I am a sculptor. Perhaps this was why The Shape of Air, the oxymoron used by the curators Heather Swann and Mary Knights as the title of their show at the Plimsoll Gallery, Hobart, was so intriguing. It seemed clearly impossible - something the Mad Hatter may have come up with – a challenge, and what's more, a dangerously formalist sounding one at that.

Consisting of the work of eight artists from across Australia, The Shape of Air was a show that perhaps could only have originated in the Island State. Located on the edge of nothingness, Tasmania often seems to struggle for a sense of form and identity. Yet those that know the place well attest to the uncanny beauty that this one-third wilderness contains – a uniquely 'Tasmanian' condition of a liminal engagement with an indecipherable void – a concern clearly echoed in the spatial concerns of the show.

Drawing has traditionally been the territory in which issues of spatial relationships are thrashed out, and there was a strong sense of the diagrammatic in the work of both Neil Taylor and Sandra Selig. Taylor's Play Pen, a visually buzzing hive of Matrix green-coated wire mesh, seemed to describe some ideal quantity, rather like the indexical units that define the metre, kilogram or amp.

While resisting the obvious pun on the wire-frame modelling used to describe space in contemporary virtual media, the piece also drew on an earlier system of representation, Albertian perspective, one of the most remarkable features of which was that it was concerned with describing explicitly objects in space, rather than the space itself. There was no such thing as the shape of air in sixteenth century Italy. In compounding the equation, Taylor creates an object that is space. However while Taylor's air remains a void, a blank grid or empty graph, Selig designates a space that is charged, articulating an apex or crescendo in the magenta and green colouring of 3D-glasses. There was clearly a nod towards Sol Lewitt's minimally manic wall-drawings, as well as CAD and screen-savers; yet there was something surprisingly profound about object (tint). The cyberesque qualities managed to spill over into the metaphysical, parting space like Moses allegedly parted the Red Sea.

Sebastian Di Mauro Astroflirt 2002, Astroturf and steel, 253 x 180 x 105 cm, courtesy of Dianne Tanzer Gallery

This was perhaps the most ambitious aspect of the show: to introduce a spiritual reading of the shape of air. Ghosts, shades and apparitions, evocative of shapes in air, are notoriously difficult subjects for western art to represent (consider the metaphor of the dove for the Holy Spirit). Mick Kubarkku, a Kunwinjku artist from Arnhem land, demonstrated the deeply felt and entirely comfortable relationship with spirituality that Aboriginal art is able to convey. His Yawkyawk Spirits and Mimih Spirits, wooden carvings painted with natural pigments, were to Western eyes strongly reminiscent of Giacometti (who also described his attenuated figures, reduced almost to the two dimensional gesture of line, as gods). The raw wood and ochre colouring brought the immediate detail of the outback into the gallery: what was more gradually appreciated was the profound sense of geographic and historic magnitude that emanated from the images.

Kubarkku's figures, like Alice, took us to the landscape of a dream world the other side of the glass – as did Geoff Parr, but from the opposite technological extreme. Air Born, a triptych of wall-length digital prints of a Tasmanian sunset were shown mounted above perfect white plinths, each faced on their upper surface with mirrored glass. The prints appeared to have been greatly magnified from a magazine, in the process emphasising the CMYK separation used to print the coloured image. It was as if we were looking at a flight simulation or Genesis through a moiré haze, returning us to the basic question of what image making (shaping air) may be. The softened reflection glowing in the glass surfaces of the plinths borrowed a trick from Brunelleschi, the father of perspective, who used reflections of paintings to smooth art into form. Parr, however, left us hanging, suspended in a split infinity, wishing to boldly go.

The Shape of Air was a brave re-oxygenation of an art environment on the edge of the world, and praise must go to the vision of the curators in the chosen populace of their Wonderland. In a contemporary climate that is frequently embarrassed by questions of form and image, this was both a welcome reminder of what visual language is all about, and a thoughtful analysis of the mediums we inhabit.