The next step in gravitational wave astronomy
The most sensitive instrument in the history of astronomy is going to be built in deep underground caverns and tunnels, a few hundred metres beneath Earth’s surface. It may sound crazy, but it’s true. The Einstein Telescope (ET) isn’t going to collect light photons and won’t provide us with stunning images of nebulae and galaxies. Instead, the almost €2bn-facility will register gravitational waves, the infinitesimal ripples in spacetime that propagate through the Universe at the speed of light as a result of the collisions and mergers of ultra-compact neutron stars and gluttonous black holes.
The telescope will form a giant equilateral triangle, measuring 10km on each side. Powerful beams of laser light will travel up and down these arms, bouncing off mirrors to gauge the length of the arms to see if they change by even a fraction the width of an atomic nucleus. When such a change does occur,
