Part of the Linac 4 booster at CERN, as seen on May 9 in Meyrin, near Geneva. The booster will allow the LHC to reach higher luminosity in the next few years.
Fabrice Coffrini/AFP/Getty Images
Astrophysicist Richard Gaitskell, from Brown University, leads a team hunting particles of dark matter about a mile beneath Earth's surface. No luck so far, but Gaitskell is still hopeful.
Physics is full of big, interesting questions about phenomenon such as black holes. This illustration shows the supermassive black hole at the heart of the active galaxy NGC 3783 in the southern constellation of Centaurus.