Improvement and Evaluation of Teaching Materials for Measuring the Diameter of the Sun by Using Shading Sheet

Abstract

In the third grade of lower secondary school science course units on “The Earth and Space” and “The Solar System and Stars”, students are required to observe the Sun and find its characteristics, including shape, size, and surface area, based on the observation records and data. Regarding the size of the Sun, the goal is for the students to understand that the Sun is the largest object in the solar system, and for this purpose, it is necessary to compare the size of the Sun with the planets in the solar system. If the size of the Sun can actually be measured, this will lead to a more realistic understanding among the students. Teaching materials for measuring the diameter of the sun have been proposed in the past. In this paper, based on previous findings and the principle of measurement, we developed an experimental apparatus by attaching a light-shielding sheet to a wooden board with a scale. The teaching material has been improved to enable not only direct measurement of the apparent magnitude of the sun, but also more accurate measurement. The improved teaching material was utilized and evaluated in a practical experiment with third-year lower secondary school students, and the average diameter of the sun obtained by the pupils in the class was 1,450,000 km with a margin of error of 2.1%.