The Nobel Prize in Physics for 2017 was awarded to Kip Thorne, Rainer Weiss, and Barry Barish for detecting a disturbance in the universe so faint that it moved their 4-km-long long detectors by one thousandth of an atom, or by 10–13 meters. While this was predicted by Einstein’s general theory of relativity in 1915, it took more than a hundred years of technological developments to reach this accuracy. Even a couple of years ago, it was thought that the technological precision was impossible to achieve. This article traces the history of this impossible achievement.