THE MEASURE OF EVERYTHING

Peter Gallivan discovers how our world relies on the amazingly precise science of measurement – from powering your phone to sending spacecraft millions of miles into space.

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Did you know that the heaviest vegetables ever grown weighed more than a car? Or that the most powerful electrical force in the universe is equivalent to one trillion lightning bolts? Or that there are almost as many molecules of sugar in a can of coke as there are stars in the universe? All these amazing facts are examples of measurements made by scientists to help us understand what makes the universe tick.

You probably haven't thought much about the importance of measurement, but mistakes can show just how vital it is to get right. In April 1990, the Hubble Space Telescope was launched on its mission to take detailed images of space.

The telescope was built around a curved mirror 2.4 metres across, designed to bend light and create sharp images. As data began streaming back to Earth, though, scientists were shocked to find the pictures were blurry. After months of investigation, engineers realised that the curve of the main mirror was incorrect by just 1/450th of a millimetre. The tiny flaw was traced to a fault in a measuring device used to test the mirror's shape as it was being built. Fixing the telescope required an ambitious and expensive space mission.

Rough beginnings

The fact that such a minor error could cause such a major problem shows just how much modern science and technology rely on precise and accurate measurements. However, measurement has always been part of human civilisation.

Amazing stone structures like Stonehenge, built as far back as 5,000 years ago, line up precisely to the Sun at certain times of the year some of the oldest evidence of people measuring the world.