Weighing the vacuum with the Archimedes experiment

We present the status of the art of the Archimedes experiment, devoted to measure the weight ofzero point energy by weighing the condensation energy of a layered type II superconductor. Theexperimental scheme of the Archimedes experiment is presented and the sensitivity needed forthe final measurement illustrated. The results of the balance prototype are presented showing thetorque sensitivity of about 10−11 Nm/sqrtHz in the region of frequency from about 50 mHz uptwo 150 mHz. The major upgrades needed to reach the desired final sensitivity are discussed.