A team of researchers, at Princeton University's Materials Research Science and Engineering Center and from the Universities of Michigan and Florida, has observed electrons moving through a crystal of bismuth metal behaving like light.

Squeeze a crystal of manganese oxide hard enough, and it changes from an electrical insulator to a conductive metal. In a report published online this week by the journal Nature Materials, researchers use computational modeling to show why this happens.

Australian scientists and optical engineers will be making a perfect sphere that may one day re-define the kilogram - and tomorrow they're taking delivery of the cylinder of silicon from which it will be made.