  By performing X-rays measurements in the "cosmic silence" of the underground
laboratory of Gran Sasso, LNGS-INFN, we test a basic principle of quantum
mechanics: the Pauli Exclusion Principle (PEP), for electrons. We present the
achieved results of the VIP experiment and the ongoing VIP2 measurement aiming
to gain two orders of magnitude improvement in testing PEP. We also use a
similar experimental technique to search for radiation (X and gamma) predicted
by continuous spontaneous localization models, which aim to solve the
"measurement problem".
