Gravitational waves are coming closer

The new Advanced Virgo interferometer laser beam injection system was switched on on Friday, September 26th 2014 at EGO, the European Gravitational Observatory.
The big interferometers, built to detect gravitational waves for the first time, almost one century after Einstein announced their existence in 1916, are being improved.
On the Earth, there are only four such giant interferometers, with arms up to 4km long: Virgo, near Pisa; GEO600, near Hannover; and the two LIGO interferometers, in Louisiana and Washington State…