Diggester sends this quote from an article at the BBC: "The ID24 beam line at the European Synchrotron Radiation Facility will use X-ray beams to subject iron and other materials to extraordinary temperatures and pressures. How the X-rays are absorbed should give insight into the mysterious processes going on at and near the Earth's core. For example, the work could unravel why the Earth's magnetic field can 'flip.' ... The samples are compressed at a pressure millions of times higher than that on the Earth's surface. High-power lasers are then fired through the diamonds at the samples, heating them to higher than 10,000C. Then X-rays are used as a probe to determine the precise composition and chemistry of samples."