The American holiday of Thanksgiving comes with one nationwide tradition -- turkey! Millions of people throughout the United States sit down to a big meal that has turkey as its main course. Turkey is a tradition because this is what people believe the pilgrims ate when they celebrated the first Thanksgiving in 1621.

For many people, the turkey cooking in the oven comes with another tradition -- the pop-up timer! This simple piece of technology lets everyone know when the turkey is done -- when the red indicator stick pops up, it is time to eat!

Did you ever wonder how that red stick knows that the entire turkey is finished? In this article, we will focus on how the pop-up timer determines the cooked state of the turkey that will soon be your meal!