
Make a periscope with a really long tube. Hint: Don’t have one-litre milk cartons? Any sized box works as long as you have big enough mirrors positioned at a 45° angle. Hint: You can create a forward-looking periscope by facing the mirrors in opposite directions, or a backwards-looking one by facing the mirrors in the same direction. You may have to pinch the open end of the upside-down carton so that it can slide into the other carton.
Once the mirrors are firmly secured, join the two cartons together by sliding one into the other. Slide a mirror into the carton through the slit with the shiny side facing the window and the dull side facing the “roof.”. Make the cut as long as one side of the mirror. Use a craft knife (an adult should do this part) to cut a slit along the 45° line. Draw a line between that mark and the opposite corner of the square you’ve measured out, and you’ll have a 45° angle. Hint: To measure a 45° angle on any sized box, simply measure the width of the box, measure the same distance up along the side of the box, and mark that point. Along this line, cut a slit into the cardboard. Measure and mark a 45° angle on the side of the box, extending from the bottom corner of the window up to the back of the box. Carefully cut out the windows of the cartons. Provide each student with two prepared cartons, two mirrors, scissors, tape and stickers/decorations.
Optional: If your students are younger and need help with careful cutting, measure and cut the slit for the mirror. (The students can cut out the rest of the window using scissors.) Use the craft knife to cut along one of the sides of the window. These will be the windows of the periscope.
Using a marker, draw a square at the bottom of each carton. Use a craft knife to cut off the top of each carton. How could you build your periscope to see behind you? Describe how light rays can change direction.ĭemonstrate how visible light is reflected.Ģ small, flat mirrors (less than 9 cm in at least one dimension)Ĭan you trace the path of light from the object, through the periscope, to your eye?