AC is being produced at a power plant using, let's say, a giant dynamo. A coil is being rotated rapidly through a magnetic field thus generating AC current. This current is then regulated, transformed and sent through the power lines to my town.
Now, if I touched one of the lines while being on the ground, I'd get electrocuted and die. Why? The current flows from one side of the coil of the generator to the other side of the coil (I'm imagining a dynamo here), so why do I close a circuit if I touch the ground, a large (infinite?) resistance? I only touch one cable of the dynamo coil. Don't I need to also touch the other side of the generator for current to flow through me?
It would seem more logical if I only got electrocuted if I touched two cables on a power line, both leading to different sides of the dynamo at the power plant. It doesn't seem like I'm closing a circuit. And would this (electrocution) also happen if the line was transporting High Voltage DC?
What am I missing?