A02: Sundial 日晷

Before the invention of modern clocks and time measurement instruments, people in the past used various ways to measure time. One of the instruments used in common by different civilizations was the sundial. The sundial is a simple instrument that makes use of the position of the sun in the sky and its shadow on the ground to measure time.

Mission:

Work as a group to design and make your own sundial.

Instructions:

1. By following the instructions in the websites given in the reference list or other resources on the Internet, design and make a sundial of your group.

2. Test your sundial in the campus by following the instructions of your instructor. Answer the following questions and present your data and your sundial to the rest of the class.

Questions:

1. Is your sundial accurate? (Is it consistent with your watch?)
2. What are the factors that would affect the accuracy of your sundial? (Hint: Consider the time, location, weather condition, direction, height, latitude, etc.)

Reference:

1. Sundials on the Internet (http://www.sundials.co.uk/projects.htm)

2. BBC (http://www.bbc.co.uk/norfolk/kids/summer_activities/make_sundial.shtml) (Note: This site provides a template for making a simple sundial, but the direction of the gnomon is incorrect. The right angle should be on the other side. Consult the first reference above if you want to use this template.)

3. The Sundial (http://www.phy6.org/stargaze/Sundial.htm)