Kaleidoscope: Definition, Principle, Working and DIY

A kaleidoscope is a toy for kids that is both fun and interesting. It consists of two or more reflecting surfaces, and these surfaces are tilted with respect to each other at a certain specific angle. This helps to create symmetrical patterns at the end of the kaleidoscope when viewed from the other end. By rotating the tube, which is lined with reflecting surfaces consisting of coloured pieces of glass, symmetrical patterns are obtained.

Scottish inventor David Brewster invented the kaleidoscope on \(10^{\rm{th}}\) July \(1817.\) The word kaleidoscope is composed of ancient greek words. It consists of ‘Kalos and ‘eidos’, which mean “beautiful” and “what is seen”, respectively. Here the word ‘skopeo’ means “to look.”

Sunlight bounces by the glass and the coloured beads present inside the kaleidoscope. The light reflecting from the mirrors create beautiful, encapturing patterns within the tube. These picturesque patterns are a delight to the eyes of the observer who looks into the kaleidoscope. In fact, as one rotates the tube, patterns change, and one pattern merges into another, and we get an assortment of wonderful visions inside a kaleidoscope.

Principle of Kaleidoscope

The use of two main principles can help in understanding the working of a kaleidoscope:

1. Laws of reflection of light
   a. The angle of incidence is equal to the angle of reflection.
   b. The incident light, the reflected light and the normal all lie in the same plane.
2. White light consists of a combination of seven colours or VIBGYOR.
   a. When white light hits the surface of a mirror, it gets reflected such that the angle of reflection is equal to the angle of incidence. Within a kaleidoscope, we have multiple mirrors lined along the length of the tube. Thus, light rays strike one mirror surface after the other and multiple reflections occur within the kaleidoscope. Due to these reflections, beautiful patterns are obtained.
3. When a ray of white light passes through coloured objects, most of this light gets absorbed by these objects within the kaleidoscope tube.

Working of Kaleidoscope

Even at its basic level, a kaleidoscope consists of two or more mirrors or reflective surfaces inclined at an angle with respect to each other such that they form a triangle or a V-shape.  A tubeorcase (i.e. it appears like a spyglass) defines the body adjoining the mirror assembly. A set of colourful objects is placed at one end of the mirrors, and at the opposite end, there is an eyehole to allow viewing.

An amazing fact about a kaleidoscope is that what you look at once, the exact same pattern will never be formed again. The container which contains these colourful objects can be as large as the kaleidoscope tube and at times even larger than that. But at a given time, we only see the objects that fall within the triangle space of the object holder.
To understand what happens in a kaleidoscope, think of a Pizza; each slice of the pizza represents the object put within the vee-shape or the triangular area at the end of the tube. Now, place the slice of pizza within two mirrors placed adjacent to each other at an angle. You will be able to see almost the entire pizza recreated by the multiple reflections of the single slice occurring side by side.

We know that pizza, like a complete circle, is \({360^ \circ }\) around. Each triangle portion within the kaleidoscope or each slice of pizza is like the portion of that circle. The larger is the size of the wedge or the slice, the wider will be the angle it makes at the centre of the circle, or the smaller is the size of the wedge, and leaner will be the angle it makes at the centre of the circle. Thus, the angle made by a single slice or wedge in a uniform circle would determine the number of reflections of the given slice. For example, if your slice is the size of a quadrant of a circle (like in a pan-pizza), the angle made by the slice at the centre will be \({90^ \circ }\).

Therefore, in a kaleidoscope consisting of two mirrors, we will get four reflections of the slice in the images at the end of the tube. If the slice size is half the size of the quadrant, the angle at the centre will be \({45^ \circ }\). Thus, the final image consists of eight reflections of this slice. Thus, the large the slice, the lesser the reflections and smaller the slice, the greater the reflections and so on.

Although the image, even in a simple kaleidoscope, is way more beautiful than toppings on a pizza. We obtain stunning and intricate patterns with ordinary beads, buttons, bangles, and sprinkles within a kaleidoscope. This can be attributed to the principle of symmetry; according to this principle, if a line is drawn through the centre of a symmetrical object, it divides the object into two exactly equivalent halves; they will be like mirror images of each other. In a kaleidoscope, each reflected image is symmetrical about the image next to it. The closer we join the mirrors in the tube, the better the symmetrical patterns we will get at the end.

In a kaleidoscope containing two mirrors, an intricate design of wedge reflections fills the entire circular background. Using three or more mirrors, in the end, will result in a design that fills the whole space with more intricate and detailed geometric patterns with seemingly endless reflections. As the patterns in a kaleidoscope are obtained after we shake it or rotate it, the kaleidoscope objects are never really arranged in the same way as before. Thus, no two designs will be perfectly identical when viewed from the other end.

DIY: How to Make a Kaleidoscope at Home?

Although kaleidoscopes can be elaborate, we can create our own kaleidoscope and have fun watching the various colours and patterns. Kaleidoscope is based on the principle of reflection of light. Depending on what we have on hand, we may not even have to spend a dime to design a kaleidoscope, and we follow the steps given below:

Material required to make a kaleidoscope:

1. Three reflective surfaces or mirrors of equal size
2. A cardboard box cylindrical in shape, or you can take a similar plastic pipe
3. A glue
4. A pair of scissors
5. A pencil
6. A glass plate
7. A sheet of cardboard
8. Bangles, beads and sprinkles

To put it all together, follow these steps:

Step 1: Take three mirrors of equal dimensions (length and breadth).

Step 2: Join the three mirrors along the length, such that their reflecting surface is inwards while their painted surface is outwards and glue the mirrors in this position. These mirrors are inclined at an angle of \({60^ \circ }\) with respect to each other, forming a hollow prism.

Step 3: Choose a cardboard box such that the length of the box is greater than the length of the mirrors and put the glued combination of the mirrors into the cardboard box.

Step 4: Keeping this box on the sheet of cardboard, draw a circle on the sheet and cut it. Now cover one end of the cardboard box with this circular piece and fix it there with some glue.

Step 5: Make a hole in this circular board using a pencil to look inside.

Step 6: Place pieces of bangles, colourful beads and sprinkles on the other side of the cardboard.

Step 7: Cover this side of the cardboard with a glass plate.

Your kaleidoscope is ready! Rotate the box and view the intricate patterns formed inside the kaleidoscope.

Uses

A kaleidoscope is basically an optical toy that contains three mirrors inclined towards each other at a particular angle. Some common uses of the kaleidoscope are:

1. Kaleidoscope produces beautiful patterns that fashion designers use.
2. It is used as a toy that is both entertaining and enlightening.

Summary

A kaleidoscope is a toy for kids that is both fun and interesting. It consists of two or more reflecting surfaces, and these surfaces are tilted with respect to each other at a certain specific angle. This helps to create symmetrical patterns at the end of the kaleidoscope when viewed from the other end. By rotating the tube, which is lined with reflecting surfaces consisting of coloured pieces of glass, symmetrical patterns are obtained. It works on the principle of reflection of light.

Light travels in a straight line. When a ray of light strikes on a surface, its direction changes, and if that surface is transparent, it reflects in the direction it came from. As the patterns in a kaleidoscope are obtained after we shake it or rotate it, the kaleidoscope objects are never really arranged in the same way as before. Thus, no two designs will be perfectly identical when viewed from the other end.

Learn about Prism and Dispersion of Light

FAQs

Q.1. What is a Kaleidoscope?
Ans: A kaleidoscope is an optical instrument that contains two or more mirrors inclined at a particular angle.

Q.2. Can we have a kaleidoscope with a single reflecting surface?
Ans: No, we can not have a kaleidoscope with a single reflecting surface; it should contain two or more reflecting surfaces.

Q.3. Who invented the kaleidoscope?
Ans: The kaleidoscope was invented by David Brewster.

Q.4. Write uses of a kaleidoscope?
Ans: Uses of the kaleidoscope are:
(i) It is used as a toy for kids.
(ii) It is displayed in museums for science to understand the applications of reflection of light.

Q.5. Which principle of light explains the working of a kaleidoscope?
Ans: Kaleidoscope is based on the principle of reflection of light.