If one disregards melody, songcraft, and a general air of recycled psychedelia, the thing that best categorises Luke Steele’s career to date is inactivity. In a perfect world, Empire of the Sun would have capitalised on the success of their debut album and their incendiary live shows in 2009, ushering in another album to let us soak in their esoteric and exciting world. Instead, they disappeared for four years, before returning with an album that is almost identical to the previous one. And where Walking on a Dream shimmered, Ice on the Dune thumps and hisses. The debut, whilst not…