Horse riding played a key role in human expansion and civilization. But when and how did people first master these animals? Scientists use archeology and genetics to uncover clues about the first horse riders and how they shaped the world.
Discover the science behind Leonardo da Vinci's masterpieces—and Mona Lisa's iconic smile.
Can new engineering techniques help prevent deadly bridge collapses?
Amazing fossils reveal how mammals took over after an asteroid wiped out the dinosaurs.
