Seeing is believing

Abstract

Have you ever wondered how something small like a virus or a bacterium can infect a person and cause anything from minor irritations such as a sore throat, to more severe symptoms like fever and measles, or even kill? Or have you marvelled at the elegant yet intricate double helix structure of DNA? How do we know that these things really exist or how they work? And how do we know what medicines to take to treat a particular disease? Thinking about or answering such questions was way beyond our reach until a few decades ago. Then came the discovery and refinement of crystallography in the first half of the 20th century and its application to biology from the 1950s onward. Slowly this opened our eyes to the wonders of the microcosm, showing us how biology works at the cellular, molecular and even atomic level. We live in a physical, three-dimensional world. We are born with two eyes and two ears set slightly apart. This allows us to perceive the world around us. We not only see the height and the width of any object but its depth too. This in turn allows us to understand how one thing relates to another – is it smaller, thicker, broader, behind or in front of another? Are boxes neatly stacked one on top of the other or are they randomly thrown onto a big heap?