Strong Spiral Shapes
Pupils explore how spiral arrangements contribute to strength and stability, a phenomenon often observed in nature, such as in shells. This activity encourages pupils to draw connections between spiral configurations in nature and their potential to inspire human innovations and designs.
Age Group: 9-12 years
Duration: 30 minutes
Biomimicry Connection:
This activity is a biomimicry exercise that explores structural stability in nature through spiral arrangements and links it to human design. Pupils create columns in different shapes, stacking books on them to witness how shape affects structural strength. The circular column proves to be the most stable due to its even stress distribution - spirals in nature work the same way. By connecting these observations, the activity illustrates how nature's structural strategies can inspire more robust human innovations and designs.
Activity Details:
Tools and Materials
- At least three pieces of paper per group of pupils
- Strong glue or tape
- Pile of books of around the same size and weight
- Ruler or measuring tape
Description
A spiral arrangement is very strong and stable. Imagine a staircase that goes up a tower. If the staircase was just a straight line, it would be more unstable and could collapse easily at such heights. But if the staircase was arranged in a spiral, it would be much stronger and more stable because the weight of the staircase would be distributed evenly across each step. This is why the spiral pattern is often found in nature, such as in shells. See how strong spirals are with the following activity.
- Allocate three pieces of paper per group of pupils, strong glue/tape and a pile of books of around the same size/weight.
- Instruct pupils to roll/fold the pieces of paper into columns with three different shapes: a triangle, a square and a circle. (For more information, watch this video).
- Pupils place the columns vertically on the table and stack them with books one by one. Count the number of books that each of these columns can carry.
- The circle-shaped column will be able to hold the most books (by far). Why is that?
In general, a cylindrical shape with the same material distributes stress more evenly across its surface compared to shapes with corners, like squares and triangles. This is because corners are points of concentration for stress, which can lead to stress concentration and ultimately failure of the structure. In contrast, a cylindrical shape allows stress to be distributed more uniformly over the entire surface, which can make it more resistant to deformation and failure. Spirals work in a similar way.
