Archimedes experiment: weighing the vacuum

Archimedes is an experiment devoted to measure the weight of zero point energy by weighing a cascade of rigid Casimir cavitities costituted by a layered type II superconductor, when the reflec- tivity of the cavities is modulated and thus the energy inside. In this paper the working principle of the experiment is presented and the results of the existing prototype are presented, showing the torque sensitivity of about 10−11 Nm/sqrtHz in the region of frequency from about 50 mHz up two 150 mHz. Moreover the major upgrades needed to reach the desired final sensitivity are discussed.