When I was last working on the highway, I stopped to help a motorist parked under high tension power lines. I'm driving a large Ford Transit van, fairly box shaped. My van was parked 90 degrees (perpendicular) to the direction of the power lines and 100' below them. After I had concluded with the motorist, I returned to my vehicle and touched the metal of my van, and was greeted with a couple light shocks from the metal. I decided to probe this phenomenon some more, put my entire hand flat on my van, with no shock, but moving my hand across the metal results in a very strong "vibrating" feeling.
I've also experienced this with smaller electronics at times, including the original metal backed iPod and some laptops.
I understand that the cause of the phenomenon is induction to myself and the vehicle, both positioned 100 feet below the power lines, but what I don't understand is the actual interaction between my hand and the metal, and why it feels like a vibrating feeling. Intuitively, I understand the electricity is transmitted as AC with a cycle of 50 or 60 Hz depending on locale, and the vibrating feeling matches that cycle, but physics-wise, why does my hand feel like it is vibrating when I run it across this surface?
-- Note: I'm not looking for answers about the cause of the induction. I'm looking for answers regarding why the skin responds the way it does to this.
