It's not only opposites that attract: New study shows like-charged particles can come together

"Opposites charges attract; like charges repel" is a fundamental principle of basic physics. But a new study from Oxford University, published today in Nature Nanotechnology, has demonstrated that similarly charged particles in solution can in fact attract each other over long distances. Just as surprisingly, the team found that the effect is different for positively and negatively charged particles, depending on the solvent.