Murray Gell-Mann, the Nobel-winning physicist who brought order to the universe by helping discover and classify subatomic particles, has died. He was 89. Gell-Mann died on Friday at his home in Santa Fe, New Mexico. His death was confirmed by the Santa Fe Institute, where he held the title of distinguished fellow, and the California Institute of Technology, where he taught for decades. The cause was not disclosed. Gell-Mann transformed physics by devising a method for sorting subatomic particles into simple groups of eight, based on electric charge, spin and other characteristics. He called his method the “eightfold way” after...