Perfect shapes
DR. T. V. PADMA
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Greeks believed that all things in the universe moved in circles!
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The Greeks didn't stop with thinking that a ratio was perfect. They also decided that some shapes were more perfect than others! They thought the circle was a perfect shape, and they held the belief that all things in the Universe moved in circles.
Planets move around the sun in elliptical rather than circular orbits. Ellipses look like squashed circles or ovals.
How does a ball move when you throw it through the air, or when it bounces up off the cricket pitch? When a ball is thrown upward, it traces an arc. Rainbows form arcs across the sky. The type of arc traced by a ball that's thrown up and then begins to move back down to earth is a special type of arc
Ripples and spirals
Have you watched what happens when you throw a pebble into a lake? It splashes, but what shape do the ripples take? Can you make the ripples elliptical, or are they always circular?
Watch water when it swirls in a basin as it goes down the drain. What shape does it take? Same as the ripples? No. It spirals down the drain. Do you know what shape our DNA is? Our genetic material is arranged in the form of a double helix, which is a special three-dimensional spiral.
The rules governing the shapes of spirals, arcs, waves, bubbles and ripples, their formation and their description are important in the fields of physics such as fluid mechanics, magnetism and oceanography. They can provide clues to chemists that help them understand how atoms are arranged in certain molecules.
Mathematicians study shapes and their properties. Studying the properties of shapes can give us clues that help design instruments to be efficient, to understand movement, to study light and radio waves, to engineer bridges, to make machines like helicopters and tools as simple as screws, and even to understand weather patterns and predict the weather!
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