Carsten Holler, internationally known German artist, has a solo exhibition, curated by Vincente Todoli at HangarBicocca (7/04 – 31/07/2016). The exhibition unfolds through specular and parallel itineraries that require active participation from the public. Doubt has 20 works, some previously viewed and some new, connected to a sort of central axis, making them only half-visible. The other half is visible when walking the opposite side. The collection includes works based on optical experimentation, others on a playful dimension. Two Flying Machines (2015) allows the participant to explore the sensation of flying, while Double Carousel is an adult merry-go-round. Inside the Cubo di Pirelli HangarBicocca space, there is the work, Two Roaming Beds (Grey), where visitors can pass an entire night inside the exhibition, resting in two beds that continuously move. The beds move randomly at an almost unperceivable speed, ensuring that the participant will awake in a different position than when they went to sleep.