Virgo interferometer

What is Virgo Interferometer?

The Virgo Interferometer is a gravitational wave detector located in Italy at the European Gravitational Observatory (EGO) near Pisa. It is one of the most sensitive scientific instruments on the planet, capable of detecting ripples in space-time caused by the most violent cosmic events, such as colliding black holes or neutron stars. The project was started in the late 1990s as a collaboration between Italy and France and became operational in 2003.

How Does Virgo Interferometer Work?

The Virgo Interferometer uses a technique known as laser interferometry to detect gravitational waves. It consists of two 3km long arms that are positioned at a 90-degree angle. A laser beam is split, with one half of it sent down each of the arms. The beams then bounce back off mirrors at the end of the arms and recombine at the central part of the detector. When a gravitational wave passes through the detector, it causes the arms to expand or contract slightly, altering the distance traveled by the laser beams. This causes a change in the interference pattern, which is measured by the detector’s photodetectors.

Applications of Virgo Interferometer

The Virgo Interferometer, together with its sister detectors in the United States, has opened up a new era of astronomy, allowing scientists to investigate the universe in an entirely new way. By detecting gravitational waves, it provides a means of observing the most violent and energetic events in the cosmos, such as black hole mergers and supernovae. It also provides a way to test Einstein’s theory of general relativity, which predicted the existence of gravitational waves. The Virgo Interferometer is part of a global network of detectors that includes the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States and the Kamioka Gravitational Wave Detector (KAGRA) in Japan.

Example of Virgo Interferometer in Action

In 2019, Virgo, together with LIGO, detected a gravitational wave signal from the merger of two black holes. The event, named GW190521, was particularly significant as it involved the most massive black hole merger detected to date, with the two black holes having masses of 85 and 66 times that of the sun, respectively. The detection provided new insights into the formation and evolution of black holes and challenged current models of black hole formation. The Virgo Interferometer played a crucial role in the discovery, providing additional information that helped to pinpoint the location of the event in the sky.