Elenco Solar Energy User Manual

Page 14

Now, go outside into the sunlight. If anybody asks you what you are doing, answer

innocently. “I’m trapping some sunlight!” People may not understand what you are

doing, but in fact you are being very scientific. This is exactly what you are about

to do! Insert your index finger into the small hole of the cone. Stand in sunlight and

slowly turn around, revolving in a complete circle. You will find there is a point where

your finger feels much hotter. At that point, of course, you are facing the sun.
Now, still keeping your finger in the hole, lower and elevate your arm. There comes a

point where you will take your finger out quickly! There is no danger that you will

burn your finger, but it will get uncomfortably hot. If you insert a candle into the

opening, instead of your finger, it will melt like butter! A bit of rubber will start to

smoke and smell!!!
Experiment no. 25 Homemade solar reflector
Cut out a circle with a diameter of 30 cm on another piece of card of stiff paper.

Stick some aluminum foil onto this disc just as you did when making the first solar trap.

Step 1: Bisect the circle by drawing a line

through its middle.

Step 2: Bisect this line by drawing another

line through the middle at right

angles to the first.

Step 3: Cut along the four lines from the

outside of the circle towards the

center, but stop cutting 2 cm before

you reach the center.

You disc should now look like this:

Now punch a 2 mm hole at the center of the

disc.
Measure and mark a point 2 cm to the right of

each slit and overlap the two sides of the slit so

that the one side comes to lie on the other, at the

point you mark.
Do this with every slit and fasten it with glue,

tape or staples.
You have made something that looks like a

Chinese hat. This is your solar reflector.

Of course, the silver paper must be inside!

Go out into the sunlight and try it out.
Compare it with the solar reflector that comes

with this kit.

2 cm hole at center

2 cm

90º

pencil mark 2 cm from radius

13 cm slit
along the radius