For years scientists have searched for “dark matter” to make Einstein’s theory of gravity match the actual motions of distant galaxies. It’s wasted effort, physicist John Moffat says. His idea: Change the theory instead. Moffat chronicles centuries of steps and missteps taken to shore up an imperfect framework of physics and offers a simpler alternative, sans dark matter and even black holes. You won’t need math to understand his logic, but you’ll have to take his word on the solution.