Mirror, Mirror in a Tube

Written By: Ibbie Zou Edited By: Mischa Wijesekera

Have you ever looked through a cylindrical tube and watched colors shift into perfectly symmetrical patterns with every twist? This mesmerizing toy, also known as a kaleidoscope, has captivated  people for over 200 years. The science behind it is simpler than you may think.

A Happy Accident Took the World By Storm

In 1816, a Scottish scientist named David Brewster was experimenting with light and mirrors when he accidentally discovered that reflections between two angled mirrors could create perfectly symmetrical, colorful images. He named his invention the kaleidoscope, from Greek words meaning “observer of beautiful things.” 

In just three months, over 200,000 kaleidoscopes were sold to street vendors, scientists, and artists. Kaleidoscopes weren’t just toys, but they were seen as scientific instruments. By the mid-1900s, kaleidoscopes became more commonly known as children’s toys. 

So How Do Kaleidoscopes Actually Work?

A kaleidoscope is essentially a tube with two or three long mirrors inside, angled toward each other. One end contains a compartment filled with colorful objects such as beads, glass chips, or sequins while the other end has a peephole to look through. 

When light passes through the objects, the mirrors reflect the images back and forth repeatedly, creating a circular, symmetrical pattern. The angle of the mirrors determines how many “slices” appear. For example, 60° angles create six sections. When you rotate the tube, the objects will shift into a different arrangement every time. 

DIY Kaleidoscopes

Did you know that you can make your very own kaleidoscope at home, without being a scientist or having a lab? All you need is a few simple supplies and about 20 minutes!

Materials

Paper towel tubes

Mylar sheets or aluminum foil

Plastic wrap or wax paper

Tape and scissors

Rubber band

Colorful beads or sequins

Steps:

1. Cut three strips of your mylar sheets or foil, each about as wide as one-third of the tube’s inner diameter, to fit inside your tube. 

2. Line up your strips, leaving a tiny space between each one, and tape over the spaces. 

3. Fold the taped strips into a triangle shape, shiny side in. Tape along the top to keep it secure. 

4. Slide the mirror triangle into the tube so it fits snugly from end to end.

5. At one end of the tube, cover the opening with a small piece of plastic wrap and secure it with a rubber band. Drop in a handful of beads or sequins on top - this is your color compartment!

6. Cover the compartment loosely with another piece of plastic wrap so light can still pass through but the beads stay in.

7. Point the bead end toward a light source, look through the other end, and slowly rotate. Enjoy your new colorful toy!

Feel free to experiment swapping in different materials like candy wrappers, magazine scraps, or confetti to see how the patterns change. The kaleidoscope rewards curiosity, just like it did for Sir Brewster!

References

1. “A Brief History of Kaleidoscopes.” Camera Obscura & World of Illusions, 29 Jan. 2021, https://www.camera-obscura.co.uk/article/history-kaleidoscopes/.

2. Bellis, Mary. “The History of the Kaleidoscope and David Brewster.” ThoughtCo, 29 April 2025, https://www.thoughtco.com/history-of-the-kaleidoscope-1992035.

3. Priddy, Sumpter. “How a Scottish scientist's invention influenced 19th-century American decorative art.” The Huntington, 17 July 2020, https://www.huntington.org/frontiers/kaleidoscope.

4. Zafarris, Jess. “The Etymology of ‘Kaleidoscope.’” Useless Etymology, https://uselessetymology.com/2019/07/05/the-etymology-of-kaleidoscope/.