I will give your family a short tour (~15 minute) of a computing center in the UW-Madison Physics Building (1150 Chamberlin Ave). The computers process data from a particle collider in Switzerland. There is about 6PB (6000 TB) of data storage capacity. This means lots of hard drives and lots of blinking lights. (Kind of fun to watch blink.) The computation creates a lot of heat and large air conditioners are needed to cool the rooms. Eddies of hot and cold air can be felt swirling around. The noise from computer fans is also surprisingly loud. After the tour your family may want to visit the Physics Museum for some independent exploration of physics demonstrations.