I have a pair of shoes, which seem to isolate me from the ground. In effect I'm gathering static charge and every time i grab an aluminum door handle, that current discharges and that hurts. Ouch.
I invented a way to workaround that: when I'm going to touch door handle, first I take my Skeletool (a stainless steel multitool) and touch the door handle with it. Sometimes I even see the small spark and hear the discharge and then I can touch the handle myself unharmed.
But what interests me is: why discharging through the multitool does not hurt? This is an electrical current flow what hurts and the current flows the same way even if I hold the tool in my hand. Tool has surely less resistance than human body, so it shouldn't change anything. But it does not hurt 🙂
Why?
Best Answer
When discharging without a tool, the whole charge exits your body through a small skin surface area, say $0.1$ mm$^2$.
When you hold a tool that surface is much bigger; perhaps $100$ cm$^2=10,000$ mm$^2$.
That means that the current flowing through neurons in that area is much lower, and perhaps low enough as to not be felt.
Pretty much the equivalent of spreading the same electric current through $100,000$ cables instead of $1$.