Shedding Light on the Subject

This activity explores the development of a mathematical model for the decay of light passing through water. The goal of this investigation is a rich exploration of exponential models in context. Throughout the activity, movie clips are available to see this activity in action in the classroom.

Math Content

The goal of this investigation is a rich exploration of exponential models in context.

Individual Lessons

Lesson 1 - Light in the Ocean

In the first lesson, students make a conjecture about how the intensity of light changes as a function of the depth of the ocean. A video clip is used to prompt thinking, and students propose a graph that represents light intensity vs. depth.

Lesson 2 - Gather Data

To test their conjectures, students gather data using one of three different methods: using a simulated online dive; covering a tank with plexiglass to simulate ocean water; or, incrementally filling a column with water to simulate increasing depth.

Lesson 3 - Analyzing the Data

In the third lesson, students identify a function that models the data. An interactive graphing tool can be used to determine a function that fits the data points.

Lesson 4 - Reflect On Your Work

This lesson contains extension activities that can be used as follow-ups to the light intensity investigation. The extensions rely on exponential models, but each uses a different context.