Historically, the atom has remained the focus of deep reflection and scientific analysis. Several breakthroughs have unraveled its true nature. (see Box). Today, the atom is explored with the help of innovative microscopes which do not need visible light to do so. The focus is not just on understanding the atom but on using it to probe materials and the human body and its workings as well as create matter on an atomic scale.

   A new revolution is under way. It was only in the 1850s that a German engineer, Carl Zeiss improved the lens of the microscope. Still, light microscopes could not resolve organisms smaller than bacteria or a virus. The principle underlying the limitation was explained in 1873. A German physicist, Ernst Abbe, pointed out that any object smaller than half the average wavelength of light could not be resolved in light microscopes. In other words, anything less than 0.2 millionth of a meter or 200nano metres, cannot be seen. Abbe....