Physics42nd St paradox: Cull the best to make things better Bench your best player to win the series. Close roads to get everyone home faster. Can we harness the power of Braess's paradox, asks Justin MullinsFeatures
TechnologyUltrasound killed the surgical star From brain to prostate, focused waves of sound can reach places a scalpel can't, putting us on the brink of a surgical shake-up, finds Helen ThomsonFeatures