At 4 a.m., while most of New Jersey slept, a Princeton Plasma Physics Laboratory (PPPL) physicist sat at his computer connected to a control room 3,500 miles away in Oxford, England. Years of experience running fusion experiments in the U.S. helped guide the U.K. team through delicate adjustments as they worked together to coax particles of plasma—the fourth state of matter—to temperatures that match those found at the heart of the sun.
