If you want to witness the upcoming solar eclipse, be careful. Your mother was right: never look directly at the sun, as you can seriously damage your eyes. One way to safely view the sun during an eclipse is with eclipse glasses, which have special solar filters. But if you don't have eclipse glasses — or don't trust them because of the numerous counterfeit versions on the market — there's an alternative that's both safe and easy to make: a pinhole projector. You can create this nifty viewer with a cereal box, or you can even fashion a simple one out of two pieces of white paper.
Trace the bottom of an empty cereal box with a pencil on white paper.
Cut out the rectangle you've just traced, and tape it to the bottom of the inside of the cereal box. The sun will be projected onto this white piece of paper.
Close the top of the cereal box, and cut a rectangular opening of about two inches wide from the left and right side of the box top with a hobby knife or scissors.
Seal the middle section with duct tape or packing tape.
Add Aluminum Foil
Cut a piece of aluminum foil that is about one inch larger on all sides than one of the openings. You can choose either the left or right opening.
Tape the piece of foil in place.
Poke a Hole
Using a small nail, poke a hole in the middle of the aluminum foil. You can also use any sharp, pointed object like a push pin or a pen. Your pinhole viewer is now finished.
Look Through the Opening
Go outside and stand facing away from the sun. Hold the pinhole viewer so that the sun is shining down on the aluminum foil section, and look into the box through the opening.
You may have to adjust the angle of the box until you see the projection of the sun at the bottom of the box. Because your face is covering up the opening, the inside of the box will be very dark, allowing you to see the projection more clearly.
As the moon covers the sun, you will see a projection of the solar eclipse — safely and without eclipse glasses.
A Basic Pinhole Projector
If you don't have time to make a cereal box projector, two pieces of white paper will do the trick.
Make the Projection
Cut two pieces of white paper to about eight inches by ten inches. The more rigid the paper the better, so use cardstock if possible.
Poke a Hole
On one of the pieces of paper, poke a hole in the middle with a small nail.
View the Sun's Projection
Go outside, and place the white piece of paper without a hole on the ground. With the sun at your back, position the piece of paper with a hole above the paper on the ground so that its shadow can be seen. The projection of the sun will appear in the middle of the shadow.