Guido Pizzella, one of the fathers of gravitational wave research, has passed away

It is with great sorrow that we learn of the death of Guido Pizzella, one of the founding fathers of gravitational wave research. Together with Edoardo Amaldi, he founded experimental gravitational wave research in Italy in the early 1970s, designing and leading the implementation of the Explorer and Nautilus resonant bar detectors.

The functioning of Explorer, which was operational at CERN from 1990 to 2012 thanks to the involvement of INFN, and later Nautilus, at INFN’s Frascati National Laboratories until 2016, relied on large masses (the bars) of metal that were properly isolated from external vibrations. Deformations in the fabric of space-time caused by the passage of a gravitational wave were supposed to excite the mechanical resonance frequencies of the bar and thus be detected.

This mechanism turned out to be insufficiently sensitive to pick up gravitational waves, but the importance of these experiments for the advancement of gravitational wave research was enormous: Adalberto Giazotto and Alain Brillet took these results into consideration to develop the proposal to build a gravitational wave detector based on interferometry instead, Virgo. For this in 2016, the Italian Society for General Relativity and Physics of Gravitation (SIGRAV) awarded the Amaldi Medal to Pizzella and Giazotto.

“Guido Pizzella played a huge role in the start and growth of the field of gravitational wave research, making a lasting impression on the scientific community.” said Virgo Collaboration spokesperson Gianluca Gemme ”Besides his amazing scientific work, Pizzella was also a well-loved professor, first at La Sapienza University, and then at the University of Rome Tor Vergata, deeply influencing many students and colleagues.”

Early in his scientific career, Guido Pizzella worked with James A. Van Allen and Scott E. Forbush in the study of the Earth’s magnetosphere, bringing contributions in the study of the stability of Van Allen belts and the mechanisms of particle acceleration. Based on his experience in the U.S., he returned to Italy and devoted himself to the design and implementation of an experiment to measure the solar wind using the first ESRO (European Space Research Organization, now ESA) eccentric-orbit satellite. He was president of the Italian Group for Cosmic Physics (GIFCO) and founder and first director of the Laboratory for Plasma in Space at CNR. His interest in Cosmic Ray Physics never faded resurfacing after his retirement, when he attempted to verify by analyzing data from INFN’s PAMELA collaboration an old topic that had never been fully resolved: the possibility that Jupiter, a planet endowed with a powerful magnetosphere, could be a generator of energetic charged particles.

The scientific world loses a courageous researcher, a visionary in the world of science and a great teacher. The gravitational wave research community extends its heartfelt condolences to the family, friends and colleagues of Guido Pizzella.