samzenpus from the push-me-pull-you dept.
sciencehabit writes "It's textbook physics: An electric charge near the surface of a material gets pulled toward the surface. However, if the charge is spread out into the right shape and moves fast enough, that attraction becomes a repulsion, one physicist calculates. The odd finding could help physicists avoid unexpected effects when guiding beams of particles such as electrons."
We don't know who it was that discovered water, but we're pretty sure
that it wasn't a fish.
-- Marshall McLuhan