ABSTRACT
I first learned about simulating an epidemic several years ago from biology teachers on LabNet. 1 In one version (Averill, 1993), each student is given a small cup of clear liquid, and they are told that someone in the room has “AIDS”: That student’s cup is “contaminated” with sodium hydroxide (a base). The students then “exchange fluids” in pairs, combining the fluids in their cups and splitting the mixture. After several rounds, they each test their fluids with litmus paper. Some of the tests are positive for “AIDS” (the litmus paper turns blue, indicating a basic solution); others are negative, and the class tries to determine who was the original carrier.
