A Canadian-American cosmologist and two Swiss scientists won this year’s Nobel Prize in Physics on Tuesday for their work in understanding how the universe has evolved from the Big Bang and the blockbuster discovery of the first known planet outside our solar system. Canadian-born James Peebles, 84, of Princeton University, was credited for “theoretical discoveries in physical cosmology” and Switzerland’s Michel Mayor, 77, and Didier Queloz, 53, each from the University of Geneva, were honored for discovering “an exoplanet orbiting a solar-type star,” said Prof. Goran Hansson, secretary general of the Royal Swedish Academy of Sciences.