Instructions for trackers
Objective: measure length and direction shadow (shdlen and α in the picture below) on different times of day.
You will need a compass, a spirit level and something to measure lengths (metric tape, perhaps) and angles (like this printable protractor).
When you’re done, find me on facebook and send me all the data you gathered, including plenty of pictures and videos documenting how you made your measurements!
Your mission is to build a table that looks something like this:

The two videos below give an idea of how to make accurate shadow length measurements.
- https://www.youtube.com/watch?v=38XQ6-75CGY&feature=youtu.be
- https://www.youtube.com/watch?v=h5ljeotiJ1U&feature=youtu.be
You don’t need to do exactly as the guy on the video above. You get the idea. There’s no problem in being a little creative. Better have some fun along the way :-)
A pole as high as the one on the video is better for shadow length measurements.
It’s important to make sure that:
- The pole is perfectly vertical
- The surface where the shadow is projected is flat and perfectly horizontal
You’ll need a spirit level to make sure of the above.
For angle measurement, it might be useful to print a protractor like this one. You can stick something pointy (like a toothpick) perfectly vertically at the center, and than draw little dots at the tips of the shadows at different times. After you’re done it will be easy to measure those angles.
This video contains instructions that may help you understand how the angle measurement works:
https://www.youtube.com/watch?v=LW6UIPP2_oA&feature=youtu.be
