Funded by the United States government at a cost of more than $1.1 billion (about £800 million today) and jointly operated by the Massachusetts Institute of Technology (MIT) and the California Institute of Technology (Caltech), Ligo began operating in 2002 after eight years of construction with the goal of perceiving processes that, despite their force, are extraordinarily tiny once their effects arrive on Earth. “By the time gravitational waves from Ligo’s first detection reached us, the amount of space-time wobbling they generated was 10,000 times smaller than the nucleus of an atom,” the observatory noted. Einstein came to doubt whether...