Haunted by the cystic fibrosis patients he could not help, one Iowa doctor commits his life to understanding what is broken deep inside their cells.

Tie a trefoil knot in a piece of string, seal the ends together, and try to wiggle it free without cutting. In three-dimensional space, the knot holds firm. Add a fourth spatial dimension, however, ...

Toyota is pulling back more than 550,000 Highlander and Highlander Hybrid SUVs in a recall that affects one of the ...