����ý

Shapes are everywhere.

Whether you’re walking through a major city or the most tranquil forest, you’ll be surrounded by items that resemble circles, rectangles, squares and many more.

����ý Bitesize takes a look at five shapes that naturally appear around us, and what they tell us about the world.

Circles in tree rings

When a tree is cut down, you can see circular rings on their stumps. It’s well known that by counting the rings, you can tell the age of the tree – but there is also plenty of other information stored within these circles.

The rings can tell us what the weather was like during each year of the tree’s life.

Each ring has two layers – one light, one dark. The light part forms in spring and early summer, when the tree is growing, while the darker section forms in later summer and into autumn.

The layers of the ring can also vary in width too. Generally, they grow wider in warm, wet years and are thinner if it has been a cold and dry season.

Rectangles in tessellated pavements

To the south of mainland Australia, in the Tasman Peninsula of Tasmania, you can find hundreds and thousands of naturally-produced square and rectangle-like shapes.

Around an hour away from state capital Hobart, the Tessellated Pavements of Eaglehawk Neck is home to tile-like rocks along the water.

Formed mostly of siltstone around 300 million years ago, the rocks were disturbed by the movement of the Earth, producing cracks known as joints.

Salt crystals produced by the evaporation of the Tasman Sea combined with the joints. This process was exaggerated by consistent erosion by the waves of the water to produce the incredible rocks. They’re known as the Tessellated Pavements because they fit together, with no gaps or overlaps.

Hexagons in honeycombs

If you’ve ever seen a honeycomb, you’ve probably noticed that they’re made up of row after row of near-perfect hexagons.

Honeycombs are made from beeswax, which is created by the worker bees. For every 1lb (454g) of wax, a bee needs to consume on average 8.4lbs of honey (3.8kg) – so they need to work efficiently.

In order to not waste wax and honey, the individual cells of the honeycomb need to fit perfectly, like a jigsaw. Circular shapes wouldn’t work as they would leave a gap. But why not triangles or squares, which would fit seamlessly?

A theory, now known as the Honeycomb Conjecture, was proposed in 36BC by a Roman soldier and scholar, Marcus Terentius Varro. He believed bees created honeycomb in a hexagonal grid, as this was the best way to split a surface into equal shapes with the least total perimeter – therefore using as little wax as possible.

In 1999, mathematician Thomas C. Hales proved this 2000-year-old theory was correct.

Semi-circles in rainbows

When the weather brings sunshine and showers, there’s a chance you may see something shaped like a semi-circle in the sky.

Those conditions can produce a rainbow and depending upon where you are, their arch can look like a perfect half-circle.

But why do rainbows appear at all?

A rainbow is a spectrum of light produced by the reflection of sunlight in raindrops. Through a process known as dispersion, the typically white light that we see from the Sun is spread out into many different colours.

When the Sun is behind you and the rain is in front of you, you can see a rainbow reflected back from the raindrops.

To most people, rainbows look like a semi-circle or an arch - but in fact, they're actually full circles. Because we typically see a rainbow when we're stood on the ground, the other half is cut off by the horizon.

Rain droplets are round, so the light passing through them follows the circular shape - it's possible to see a full circle rainbow if you're stood on top of a mountain or on a plane.

Pentagons in okra

A staple part of, among others, Caribbean, Cajun and Indian cuisines, okra produces a natural pentagon shape when cut.

The vegetable was originally from Africa and is sometimes known as bhindi or lady’s fingers due to its shape.

The plant is ridged along its length and when sliced, you can see five pods containing seeds in a pentagon shape. The seeds are edible and the vegetable is often used to thicken up soup and stew dishes – but okra is also very popular as a side dish on its own.

Its texture can vary depending upon how it is cooked. When cooked in stews, such as the Louisiana staple dish of Gumbo, it can be quite slimy. However, the more it is exposed to dry heat when cooked, the less gooey and more crispy the vegetable will be.

This article was published in February 2022