On the outskirts of Grenoble, France, lies a doughnut-shaped research facility that houses one of the most advanced machines in the world. Known as the European Synchrotron Radiation Facility, or ESRF, it is a particle accelerator that uses electric and magnetic fields to propel electrons around an 850-metre-circumference vacuum ring, generating high-energy X-rays, known as 'synchrotron light', that are one thousand billion times brighter than a standard medical X-ray. The extreme brightness of the ESRF’s X-ray beams means that it has become a powerful tool for research into fields as varied as medicine, materials science and solid state physics. Thousands of researchers use the ESRF every year: it has become one of Europe's science and technology powerhouses for the 21st century. Yet one of the most intriguing uses of this massive X-ray machine has been to shine light onto the very small and very old.