Last month in Washington, D.C., at the annual meeting of the American Association for the Advancement of Science, theoretical physicist Lisa Randall of Harvard University spoke about her hopes for the Large Hadron Collider, the world’s most powerful particle accelerator. She sat down with Science News physical sciences writer Devin Powell after her February 19 talk to discuss what evidence the European collider, which is expected to operate at half power through 2012, might provide for her groundbreaking theories and for the Higgs mechanism, a process that would explain why particles have mass.