Make your own sundial 自製日晷

Welcome to Weekend Science! Every Saturday we’re going to guide you through some cool experiments that you can do at home. It’s a good idea for you to keep a record of what you do in a Science Journal. That way you can record what you learn, compare results and maybe use them to design new experiments! Remember to always ask a grown-up’s permission before trying out an experiment. 歡迎閱讀《週末科學版》!我們每週六都要為你介紹可以在家中進行的有趣科學實驗。你可以在《科學日誌》中記錄自己做了哪些活動,這樣就可以將所學的記錄下來,比較這些結果,也許還可以利用它們來設計新的實驗!先看一下《科學日誌》的點子再開始吧。展開實驗之前,記得要獲得大人許可喔!

Sat, Mar 21, 2009 - Page 13


On a sunny day, the occupants of Taipei 101 can look out of their window and tell the time without even looking at a clock. That’s because Taipei 101 is the world’s biggest sundial. When the architects designed the building, they decided to incorporate a time motif into various aspects of the building, and the sundial effect is one example of this motif. 


Sundials have been around for centuries because they are accurate and easy to make. In today’s experiment you will make your own sundial and use it to tell the time.

What you will need: a styrofoam cup with lid, a watch, a marker, a pencil, tape, some pebbles and a compass.




Step 1: Put some pebbles in the bottom of the cup to stop it falling over. Take the pencil and make a hole in the side of the cup. Then make a hole in the lid and push the pencil through both holes so it protrudes from the top at 45 degrees. You’ve made the sundial, and now it’s time to put it to work.

Step 2: It goes without saying that your sundial won’t work very well unless it’s sunny, so wait for a sunny day when you are free during the daytime to do this part of the experiment. You should start the experiment in the morning.



Step 3: Using the compass, align the pencil in the sundial with north. Wait until exactly 9:00am and use the marker to record where the shadow falls on the lid. Go away and come back at 10:00am and make another mark on the lid. Continue every hour until 4:00pm.

Step 4: The following day, try to tell the time just by using the sundial. Compare the time from the sundial with the time on your watch. How accurate is it?

(John phillips, staff writer)