Large-scale interferometers built to detect gravitational waves from astrophysical sources may also be able to test various theories of quantum gravity. Developing a quantum theory of gravity is one of the biggest challenges in physics today. Previously it was thought that the effects of quantum gravity were too small to be detected with modern technology. Now, Giovanni Amelino-Camelia of the Université de Neuchâtel in Switzerland has suggested that quantum space-time effects could provide a measurable source of noise in the gravity-wave interferometers being built in the US and Europe. Measurements would therefore we able to rule out certain theories of quantum gravity (Nature 398 216).