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.
"An idealist is one who, on noticing that a rose smells better than a
cabbage, concludes that it will also make better soup." - H.L. Mencken