Gravitational Waves are the minuscule ‘ripples in space-time’ that are emitted when objects like black holes collide. Their first detection by the LIGO and Virgo observatories has started an exciting new field of astrophysics. These instruments are kilometer-long Michelson interferometers, which measure distances between seismically isolated mirrors with a sensitivity better than 1e-19 m/rtHz using state-of-the-art optics, mechanics and control.

This presentation will focus on the next generation of instruments, which should be 10 times more sensitive. Among these is the proposed 10 km long, underground Einstein Telescope, for which the Dutch/Belgium/German border is a candidate location.