The Chinese artist and activist Ai Weiwei continues to be at the heart of major political and world events. In August, Ai travelled to the front line of the war in eastern Ukraine near Kharkiv, where he met Ukrainian fighters and cultural figures. Ai Weiwei: In a five-year period I’ve spent a year and a half here, maybe a year in Berlin, maybe a year in Cambridge [UK]. It’s just shocking”: Ai with Ukrainian troops Photo: courtesy Ai Weiwei, via InstagramTell us about your experiences in Ukraine. • Ai Weiwei: Three Perfectly Proportioned Spheres and Camouflage Uniforms Painted White, Pavilion 13, Expo Center of Ukraine, Kyiv, until 30 November