A gravitational wave detector in the heart of Barbagia

Italy wants to build the Einstein Telescope, currently under study by various scientific bodies of the European Union, in Lula, using the disused mine of Sos Enattos

A third generation gravitational wave detector in the heart of Barbagia. Italy wants to build the Einstein Telescope, currently under study by various scientific bodies of the European Union, in Lula, in the heart of Barbagia, using the disused Sos Enattos mine, an area that is also very favorable for conformation of the terrain, in granite. The challenge will be decided in 2024, as the Nobel Prize-winning physicist Giorgio Parisi explains to Il Sole 24 ore, called to chair the support committee for the Italian candidacy by the minister of University and Research, Anna Maria Bernini, and at the moment there is only one real competitor, the Netherlands, with Maastricht.

The project involves the construction of a gigantic triangular underground interferometer for the search for gravitational waves. The observatory – explains an Infn document also reported by the Sun – will be located at a depth between 100 and 300 meters, to isolate it from the movements of seismic waves, will have a perimeter of about 30 km made up of 10 km long arms at which inside will be crossed mirrors of very high surface quality crossed by a laser. If a gravitational wave crosses the interferometer, the length of the arms oscillates and this infinitesimal variation is revealed by the experiment.

Thanks to its extreme sensitivity to low frequencies, Et will allow gravitational waves to be observed regularly, thus ushering in the era of a new type of astronomy, precision gravitational astronomy. The interferometer will hunt for gravitational waves, ripples in spacetime that propagate at the speed of light, generated by ‘cosmic cataclysms’, such as the explosion of supernovae or the collision of black holes or neutron stars. The verification of the existence of gravitational waves represents the missing piece to the experimental verification of Albert Einstein’s Theory of General Relativity. Produced by stellar masses in accelerated motion, gravitational waves, due to the rigidity of spacetime, have an infinitesimal amplitude. Due to this characteristic, revealing them is really difficult and gigantic instruments are needed, such as interferometric detectors. In Italy the hunt for gravitational waves is already underway, thanks to a gigantic and very sensitive laser interferometer: it is Virgo, active in Cascina, in the Pisan countryside. The result of an Italian-French collaboration between the National Institute of Nuclear Physics and CNRS and managed by the Ego consortium.