The autumnal equinox occurs tomorrow, the first day of fall. Exploratorium presents this activity that shows how to use shadows to measure the change of seasons. By using common items, you will be able to show how the tilt of the earth’s axis changes the length of shadows. Find a basketball, light bulb, protractor, and some paper clips and follow the instructions to set up this demonstration. For teachers, there are discussion questions, video clips, and links to national standards, as well as a flash animation that shows the alignment of the earth to the sun throughout the year.
courtesy of Knovation