Take a piece of sheet metal and connect insulated copper wiring to it. Then connect the copper wiring to a battery. The sheet of metal needs to be massive, around a mile long. Then dig up some land and place the sheet metal in the hole and cover it with dirt. Would it be able to conduct a magnetic field large enough to reach the surface of the earth?
The sheet would have to be insulated, the cost to excavate/cover would be prohibitive, the current through a sheet won't produce a significant magnetic field. Other than that and other details, it's a perfect plan.
