Speaker
Description
The Archimedes experiment aims at measuring the interaction between vacuum fluctuations
and gravity. Archimedes will measure the force exerted by the gravitational field on a Casimir
cavity whose vacuum energy is modulated with a superconductive transition, by using a
balance as a small force detector. If the vacuum energy does interact with gravity, a force
directed upwards acts on the cavity and can be interpreted as the lack of weight of the
expelled EM modes, in similarity with the Archimedes buoyancy of fluid. The expected torque
generated with this modulation is of the order of $10^{-13}$ $Nm⁄\sqrt{Hz}$ . To detect such
a small force, a very sensitive beam-balance has been suitably designed. A first prototype has
been installed and tested in the SarGrav Laboratories at the Sos-Enattos site (Lula, Nuoro)
which is seismically very quiet. In the region of tens of mHz, at which the Archimedes
modulation will take place, the torque sensitivity has been recently measured to be around
$5\times10^{-12} Nm⁄\sqrt{Hz}$. At present, the final setup is being installed at the SarGrav
surface Laboratories in view of the final measurement of the quantum vacuum weight, which
is expected to be performed in 2024.
