2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/29325The RCSJ model of resistively and capacitively shunted Josephson junctions is used to describe superconducting point contacts over a wide range of resistances up to the metallic -- tunneling transition. Their small dynamic capacitance of order $C = 0.1 $fF due to the point-contact geometry results in a huge plasma frequency. The critical current is then strongly suppressed and the contact resistance becomes finite because of quantum-mechanical zero-point fluctuations of the Josephson plasma and the rather large escape rate out of the zero-voltage state due to quantum tunneling. We test the predictions of the RCSJ model on the classical superconductors lead, indium, aluminum, and cadmium.28 pages, 24 figures, We apologize for the large size due the horrible postscript drivers of all M$-Windows graphics programs, we used. Changes: reducing the size of the figures by streamlining the postscript files. Thanks to Thorsten Schwander of xxx server!. accepted for publication in J. Low Temp. Phys. vol 116SuperconductivityMesoscale and Nanoscale Physicstext