Korean-born artist Anicka Yi has let loose a bunch of floating jellyfish machines inside the Turbine Hall at Tate Modern, to encourage us to think about how machines could inhabit the world. The battery-powered aerobes, a mixture of bulbous and see-through tentacled objects, hover around the hall, which has also been filled with changing scentscapes designed by Yi inspired by smells from different periods in the history of Bankside.