7. The Information Train

The increased application of software-controlled digital electronics hinders the understanding of how things work. The information train is a scientific experiment exhibit that physically demonstrates how computers communicate. It comprises a network in which a model Lego train acts as a physical carrier transferring a picture’s pixels from one computer to the other. The sending end computer scans a simple picture, and directs a model train to send that pixel to the receiving end computer. This is done by sensing the approaching train and switching a rail junction depending on whether a pixel is on or off. The train carries on its top a piece that rotates depending on the train’s route, thus carrying the data between the two computers. At the receiving end, two sensors detect the shape’s orientation allowing the receiving-end computer to reassemble the picture bit-by-bit, pixel-by-pixel. The receiving-end computer is a One Laptop per Child (OLPC) XO-1 machine, programmed using Etoys. This provides further opportunities for motivated adventurous children to interact with the experiment’s implementation.