CLOUD (Cosmics Leaving Outdoor Droplets) experiment with the FLOTUS (Flow Tube System) illuminated at CERN (The European Organization for Nuclear Research) in Switzerland. The CLOUD experiment aims to investigate the possible link between cosmic rays and the formation of aerosol particles in the atmosphere. FLOTUS is a 3 metre long quartz tube connected to the CLOUD chamber, a large stainless steel container where atmospheric conditions can be recreated and analysed. UV (ultraviolet) light is used to simulate sunlight, triggering chemical reactions. FLOTUS pumps warmer, more humid air into the CLOUD chamber to simulate reactions that normally occur over days, in a few minutes. As global temperatures continue to rise, understanding the mechanisms responsible for aerosol formation, and the clouds they seed, could help reduce the uncertainty in climate predictions.