I've searched around and all I can find are people quoting the equations. I see it in the math, but it seems contradictory. Here is my line of thought: 1. A source maintains a voltage difference across its terminals. 2. The difference in voltage causes charge to flow from higher to lower potential around the circuit. 3. When you directly connect the battery terminals, the voltage goes to 0 and current goes to infinity. How can the voltage across the terminals drop below the emf, when that is a physical property of the source? Where does the extra voltage, as rated on the battery, "go"? How can current flow with nothing to "push" it? I guess I'm also not really clear why voltage depends on resistance. I thought it was entirely based on charge density and its arrangement in space.