ground and neutral are literally on the same leg (go look at any installation. You've got TWO wires coming in at the mains, ungrounded.)
Forgive my ignorance, I'm no electrical expert, but did you just say that the ground wire is connected to the neutral somewhere in the circuit? Or did I misunderstand you?
That's exactly right. Ground is always tied to neutral in a single-phase 120V installation. Open your breaker box and remove the front panel. You'll see it. http://i.imgur.com/hCY1jV0.png
EDIT: That "always" is assuming the house is modern wiring and not older-style two-prong wiring for the wall outlets. Those systems were just main and neutral at the box and controlled by a fusible link.
Intriguing. I'm from the UK and I believe we do it differently here because I have an RCD on my earth bar in the consumer unit. The RCD detects current on the earth wire and cuts power to the circuit instantly. An earth fault doesn't trigger the circuit breaker, it triggers the RCD. A fault between live and neutral would trigger the circuit breaker.
If I'm understanding you correctly, in the US the ground wire is functionally identical to the neutral due to the bonding. Therefore (this is my own deduction and I'd appreciate being corrected if I'm wrong) you could, in theory, invert the ground and neutral wires in the plug of an electrical appliance and there would be no change in the behaviour or safety of the appliance?
"you could, in theory, invert the ground and neutral wires in the plug of an electrical appliance and there would be no change in the behaviour or safety of the appliance?"
Generally, no. I've seen backwards wiring jobs cause 48-80VAC to run through the casing of microwaves (they usually use the casing as a floating ground.) Any wiring inversion will usually cause some issue somewhere.
This is fascinating, I'm reading lots of resources attempting to understand how this works. Thanks for your responses, I appreciate you taking the time to do that.
Forgive my ignorance, I'm no electrical expert, but did you just say that the ground wire is connected to the neutral somewhere in the circuit? Or did I misunderstand you?