The Pneumatic Sponge Ball Accelerator is inspired by particle accelerators such as the LHC. Niklas Roy, the maker, explains that although they can be huge machines with "super-cool, cryptic names," they are often incomprehensible to ordinary people and it is not possible to actually see what happens inside them with your own eyes.
"As I'm a fan of science and physics in particular, I find it a pity that the current particle accelerators make the observation of the little speedy particles so complicated," says Roy on his website. "So when the Director of the Tschumi Foundation approached me and asked me if I'd like to build a machine inside their beautiful pavilion located in the center of a roundabout in Groningen, I saw my chance: I decided to construct a machine which would bring the tremendous joy of particle acceleration to everyone."
The machine comprises a large transparent box, the inner workings of which can be seen from the outside. Two transparent bubbles (Bubble A and Bubble B) are joined by a long track of airtight pipes. There is 150 m (492 ft) of tubing through which the balls travel and Roy says they hit speeds of up to 4 m/s (13 ft/s). The foam balls are moved from one bubble to the other using a vacuum cleaner to change the air pressure and shoot them through the tubes.
The machine is activated by people placing their hand over a touch sensor. This sets the airflow running and users can reverse the direction of the airflow by simply touching the sensor again.
"Visually, it is a very impressive experience to see all the balls race through the pipes at very high speed," says Roy. "They are so fast, it is almost impossible to follow them. But when you reverse the direction of the airflow, hundreds of balls slow down all at the same time, just to speed up in the other way one moment later."