- a room with a window that faces the sun
- a small mirror, about 2 cm (3/4 inch) in diameter
- glue or rubber cement
- a safe ladder
- bits of paper and tape
- an accurate clock that measures to the nearest second
- If you live in the Northern Hemisphere, it is preferable to use a room with a south-facing window. In the Southern Hemisphere, look for a north-facing window. You will be marking the position of sunlight reflected from a fixed mirror at the same time each day.
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| Note: For a full analemma, you will need to work on the project for 12 straight months. If you have access to the room for only part of a year, you can still trace out a portion of the analemma. In general, you will need at least three months to see enough of the pattern for it to be recognizable. |
Obtain any necessary permission to use the room for about 15 minutes at the same time each day, as well as to place markers on the ceiling or wall. Select a time that you will have available each day, preferably around midday. You will make your project measurements each day at this selected time.
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| Note: If you are setting up the project in September or March, the reflection will be close to the crossed part of the analemma. If you are setting up in June or July, the reflection will be near one end of the figure eight. In December or January, the reflection will be near the other end. Think about when the sun is high or low in the sky during the year and anticipate how your figure might develop. |
To set up your project, go to the room on a sunny day close to your selected time. Place the mirror on the sill of the window you will use. Move and tilt the mirror so that the reflection of the sun appears on the ceiling or on a wall.
- Keeping your mirror in the same location and orientation, glue it in firmly place on the windowsill so that the reflection appears on the ceiling or wall where you want the project to begin. Once you have fixed the position of the mirror, any changes in the location of the sun will cause changes in the location of the reflection. Your setup is now complete.
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| Note: It is important that all of your observations are made at exactly the same time of day, to the second if possible. Do not worry if you are not able to mark the position of the reflection every day. You will probably have enough sunny days during the year to give you a clear indication of the figure. |
To begin your project, pick a sunny day. Write the date and selected time on one of the bits of paper. Then, at your selected time, mark the position of the reflection by taping the bit of paper to the wall or ceiling. If your ceiling consists of acoustic tile or similar material, you may wish to mark the position with a thumbtack or colored pushpin. If you are using a ladder, please do so carefully and safely.
Good luck!
For something different, make a floor analemma! Glue or tape a dark paper circle — about 2 cm (3/4 inch) in diameter — to the glass near the top of the window and mark where the shadow of the circle appears on the floor at your selected time each day.
Here are partial results for our analemma made with a mirror…
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