A new measurement of the exotic “atom” — consisting of an electron and its antiparticle, a positron — disagrees with theoretical calculations, scientists report in the Aug. 14 Physical Review Letters.

High energy density (HED) physics has critical applications in areas such as inertial confinement fusion and the stewardship of the nation’s nuclear weapons stockpile. Congress has requested that the ...

Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...