From 3D-printing with bacteria to cocktail-mixing humanoids, from the future of space suits to reassurances about climate change, this mind-boggling rollercoaster of a show could do with a more focused curatorial visionA teetering wall of gungy green bricks greets visitors to this year’s Venice Architecture Biennale, forming an imposing blockade near the start of the show. The blocks are made of bio-cement, incorporating fishing nets and algae dredged from the depths of the Venetian lagoon. The wall’s steeply sloping gradient follows the curve of global population growth over the last millennium, terminating abruptly near the ceiling to represent the coming peak of humanity. “What awaits us on the other side of the hill?” asks Carlo Ratti, director of this year’s biennale, as he stands in front of the momentous cliff. The answer is a great heap of gunge. A festering mountain of mould-like gunk is piled up against the back of the wall, apparently an allegory for microbial intelligence. But it could also be a metaphor for much of the work that follows in the sprawling exhibition hall. “The installation reaches towards an alternative ethics,” an opaque caption tells us. “A trans-scalar, trans-species, collaborative plasticity, that is itself just intelligence.”You might need to bring your scientific dictionary to this year’s exhibition, along with a good deal of patience. Ratti, a professor at the Massachusetts Institute of Technology, where he directs something called the Senseable City Lab, has assembled a mind-boggling cast of 750 participants, about 10 times the usual number, many of them academics, convened under the broad umbrella of