The Vienna Science Festival took place at Vienna city hall from September 9-11, 2022. At station 33 in the hall’s courtyard, a fun activity was waiting for visitors of all age groups.

The sorting network works in the following way: Every participant steps on one of the orange squares (the input nodes) and receives a card with a random number on it. They then go on to the nearest sorting node (the gray circles in the picture) and compare numbers with the other person who steps on it. The person with the lower number follows the blue line, while the person with the higher number follows the red line. This process is then repeated until everyone arrives at another orange square (the output node). In this way, all the numbers will be sorted correctly in ascending order, and this works with letters (or other input) as well! Check out our video (in German) which illustrates the process.

The activity is a great way to understand how algorithms work, and it has been designed to foster computational thinking. On the weekend of the Vienna science festival, more than 1,000 visitors participated in the activity, thereby contributing to making the station of VCLA and project ADA a great success!