Why does grounding yourself prevent feeling a static shock?

Question

Sometimes I get static electric shocks when I touch certain metallic objects. However, I seem to be able to prevent this by grounding myself by first touching that object with a small piece of metal, such as a coin. From what I gather, the reason this works is because the leap of charge occurs at the boundary between the coin and the object, rather than between my fingers and the object.

However, what I am confused about is why I still do not feel anything. Doesn't that static charge also pass through my finger on the way to the coin? So when the coin makes contact with the object, I should feel the charge pass through my finger into the coin? Or is it something to do with the fact that the contact area between my finger and the coin is much larger than that between the coin and the object, and so the sensation is diffused?

Answer 1

By creating an electrical discharge through the air onto the surface the skin, the contact, electrical path is miniscule concentrating the energy in a very small area. This causes higher localized heating and voltage potential that easily stimulate pain receptors in the skin - ouch!

But by allowing the discharge to occur through a coin, for example, the contact surface with the skin is much larger, the potentials much lower, and the coin absorbs and dissipates the heat by its high thermal mass. So your hypothesis - correct!