I seem to remember as a young child being told that it is safe to touch a Van de Graff generator (for the hair demonstration), but that if you let go before it is safe you will get a nasty shock. I know a bit more about electricity now, and I’m a little skeptical now. Is it possible to get a shock from letting go of something?
Okay, so you’re insulated from ground. The generator charges you up. You are at the same charge as the generator. You let go of the generator. Why is there a potential difference?
If the generator is running, it’s still adding more charge, so you will be instantly at different potentials
I see. Would there also be an arc if you put your hand near the generator while it was running, then?
As long as the potential is great enough to break down the dielectric of air yes.