In building a crystal radio one thing that comes up everywhere I look is the phrase. "A good ground is as important as a good antenna". So you have your circuit. Capacitor, Inductor, diode, resistor and headphones in series. Have a long wire just hanging from one place as a long wire antenna and another wire to the ground. As the currents and voltages in the circuit is going to be super tiny. Grounding isnt for safety...and I cant seem to find any explanation or maths or anything explaining what it is for. Any ideas? And is there an alternative? Such as a vitual ground? In case there is no good ground connection..say your in a building and the pipes are not metal.