Scientific American Magazine

New fossils and analyses of ancient ocean chemistry reveal the surprisingly deep roots of the Cambrian explosion

Where do protons and neutrons get their mass and spin? Surprisingly, we don't know. A new facility promises to peek inside these particles to find answers

Why dolphins, seals and other animals developed the capacity to sleep with half their brain awake

Recent disasters show how climate change is making winter storms, flooding rains and summer heat waves more extreme

A controversial theory holds that one immunization, given properly, can protect against many diseases besides its target

Missiles designed to destroy incoming nuclear warheads fail frequently in tests and could increase global risk of mass destruction

How DNA is used to store—and generate—information at extreme scales