Demo Dozen

 

Potato Salad at the School Picnic!

 

Compound growth is a powerful and common dynamic within our lives.  While its implications can sometimes be startling (or deadly, as we will see below!), it is also one of the easiest dynamic systems to explore using computer models.  Bacterial growth, (where one bacterium becomes two, two become four, four become eight, ad nauseum), is a classic illustration of that compound growth dynamic.

 

 

In this exercise you will explore the consequences of compounding through modeling the growth of bacteria responsible for food poisoning, as they multiply in the potato salad you brought to the school picnic. We’ve constructed a simple computer model that allows you to simulate the growth of bacteria at different temperatures (ranging from 35 to 95 degrees Fahrenheit) over the course of 12 hours. Recognizing that there is a small level of bacteria present at the outset (1500 bacteria per cubic centimeter in our model), your goal is to prevent those bacteria growing beyond 5 million bacteria, at which point you can reasonably expect to see toxic effects. Feel free to use this model to avoid poisoning everyone at the school picnic!

 

Should I Eat the Potato Salad?

 

Below is output from the simulation portraying four scenarios involving different temperatures.