The interactions of vacuum fluctuations and gravity is one of the most intriguing and long standing problems of fundamental physics. In spite of the accepted evidence of the reality of vacuum fluctuations also at macroscopic scale through the Casimir effect, when their interaction with gravity is considered, deep theoretical problems arise, especially put in evidence by the so-called cosmological constant problem, for which our universe exhibits a radius extremely smaller than that expected by application of general relativity to vacuum energy.
The Archimedes experiment aims at measuring the interaction of vacuum fluctuations with gravity by weighing a suitable designed stack of Casimir cavities, whose vacuum energy is modulated by a superconductive transition,
with a cryogenic and ultra-sensible beam balance. It is presently under construction and it will be located in the seismically quiet underground SAR-GRAV laboratory, under realization in the Sos-Enattos mine, in the municipality of Lula, Sardinia.
The principle of operation of the experiment is presented, together with the present status and the future developments.