From Renaissance lanterns to modern lasers. Four hundred years after Galileo’s experiment, who tried in vain to measure the speed of light from his home in Arcetri, a photonic bridge will connect, thanks to quantum physics, Villa Il Gioiello to the National Institute of Optics of the National Research Council of Florence (Cnr-Ino).

The event, born as part of the “Il Senso delle Stelle”  project from the collaboration between the University Museum System (SMA) and the Galileo Galilei Institute, in collaboration with the research institutes of Il Colle di Arcetri, will take place on Saturday 18 May at 6pm at Villa Il Gioiello (via del Pian dei Giullari 42, Florence), and is organized on the occasion of the International Day of Light, which took place all over the world on May 16th.

An aerial quantum communication link will be activated between the two buildings on Galileo Hill, i.e. without a fiber optic connection. The dovecote of Villa Il Gioiello will host the laser light transmitter which will be modulated to encode the input from an electrical signal to an optical pulse and from a classical pulse to a quantum pulse. The signal will then be transmitted to be intercepted by a telescope positioned on the Cnr-Ino turret, several hundred meters away, where the reconstruction of the original sequence will take place. The two devices will allow the public to view a message on a computer screen conveyed thanks to a fundamental technology for quantum cryptography systems that are impossible to hack.

To be sent, in particular, will be an image created by the artist Daniela De Paulis as part of the “A Sign in Space”  project, the initiative that brought together the SETI Institute, the European Space Agency, the Green Bank Observatory and the National Institute of Astrophysics, in the transmission of a simulated extraterrestrial message, using an ESA spacecraft as a celestial source. This project, undertaken in 2023, had the aim of involving scientific communities and enthusiasts from all over the Earth in the reception, decoding and interpretation of the message through a dedicated platform : the double installation on display in Arcetri, produced at Villa Galileo, during the Daniela De Paulis residence, curated by Valeria D’Ambrosio, represents an evolution of the original project.

The laser bridge “built” between Villa Galileo and the National Institute of Optics recalls the experiment attempted almost 400 years ago by Galileo: in 1638, right on the Arcetri hill the scientist tried for the first time to measure the speed of light. Two lanterns were placed about two kilometers apart with the aim of calculating the time it took for the light to get from one point to the other. Whenever Galileo uncovered his lantern, his assistant was supposed to uncover his own as soon as he saw the glow. By measuring the time it took to see the light coming from his assistant’s lantern, Galileo believed he could quantify the speed of light. The experience did not lead to any significant results but constituted a first step that initiated numerous subsequent experiments.

The appointment with the public includes a guided tour of the De Paulis exhibition in Villa Galileo at 6pm during which the connection will be made. A live streaming will follow (https://www.youtube.com/watch?si=4HksRjOUXT92jdN4&v=gly2NoqRFi0&feature=youtu.be), from the Colombaia and, at 7 pm, researchers from the University of Florence and the Cnr-Ino Sebastiano Cocchi and Giulia Guarda will hold a conference on the quantum technology used for this new connection of light on the Arcetri hill.

“The Sense of the Stars” is a series of events hosted in Villa Galileo which are aimed at citizens through a program full of meetings, workshops, activities for girls and boys. The planned initiatives revolve around the contemporary art exhibition of the return of the residence (tagliare) of the artist Daniela De Paulis, INNER WORLDS, OUTER SPACES, curated by Valeria D’Ambrosio. The project is carried out thanks to the support of the University Museum System, the Galileo Galilei Institute, the National Institute of Nuclear Physics, the National Institute of Optics, the National Institute of Astrophysics – Astrophysical Observatory and the Galileo Museum. The result was possible thanks to the technological support of QTI Srl, a spin-off company of the Cnr born within the Cnr-Ino laboratories, which now produces and markets equipment for secure quantum communications.

More information at this link 

Sistema Museale di Ateneo website