Lighthouses appear on coastlines throughout the Great Lakes and beyond. This lesson will introduce students to the phenomena of light intensity and the inverse-square law that governs it by helping them understand how a lighthouse functions to light the way for ships and boats. Plus help your young learners imagine what it would have been like to be a lighthouse keeper!
Lesson Objectives
- Know some of the history of Great Lakes lighthouses
- Understand the difference between light intensity and luminosity, as well as the inverse-square law of light intensity
- Be able to explain how lighthouses provide a lightsource for boats and ships on the waters nearby, and how that lightsource changes with distance
View the entire lesson plan including teacher background information, worksheets and more below or download for free here.
Activity 1
This activity is a video discussion of a Great Lakes Now episode segment that discusses the restoration of
Spectacle Reef Lighthouse. During the video students need to jot down four things they took away from it.
Watch a Great Lakes Now Segment
Activity 2
This activity aims to provide students an understanding of what it’s like to live in a lighthouse—and what lighthouse keepers have experienced throughout the history of active lighthouses in the Great Lakes.
Activity 3
The purpose of this experiment is for students to model how light reaches boats from a lighthouse at different distances. They will change the distance from a light source and measure the area illuminated, which they will correlate to light intensity, at each distance.
Measuring Light Intensity (Lab)
Activity 4
The purpose of this activity is for students to create a model that will communicate how lighthouses function to light the way for ships and boats.
Check out Great Lakes Now’s segment on lighthouses and the other segments featured in Episode 2201: Restore, Release on this month’s landing page.
If you use this lesson or any of its activities with your learners, we’d love to hear about it! Contact us with any feedback or questions at: GreatLakesNow@DPTV.org
