1. The problem statement, all variables and given/known data From serway's book chapter 23(electric fields), questions section. 2. Relevant equations --- 3. The attempt at a solution The obvious answer would be that it is safe because the student holding the sphere is insulated from the ground, but what does that really mean ? If I try to imagine what might be happening on a microscopic scale, I would imagine the charged particles(be it -e or +e, or both, I don't know..) next to the point of contact flowing through the body as soon as they are exposed to the charged sphere, how would the charged particles in the body "know" whether the boy's feet are touching the ground or not.. Now, if the two objects were metals, they I would expect such behaviour, since the e- in metals(solid state) are free to move around, so how come it is different for the body?