@article{Martelli_2016, title={The first direct observation of gravitational waves: a new window on the Universe}, volume={5}, url={https://oajournals.fupress.net/index.php/cdg/article/view/8705}, DOI={10.13128/Colle_Galileo-19150}, abstractNote={The first direct observation of gravitational waves using the interferometer detectors of the LIGO-Virgo collaboration has marked the start of gravitational astronomy. The extreme difficulty of such measurements called for many years of hard work, but finally, on 14 September 2015, the signal produced by the coalescence of two black holes of large mass was observed.}, number={2}, journal={Il Colle di Galileo}, author={Martelli, Filippo}, year={2016}, month={Oct.}, pages={49–58} }