Feature

Health & Medicine

Cooking Up a Carcinogen

The discovery that acrylamide—a known animal carcinogen—forms in many foods as they fry or bake has prompted the development of an international research network to investigate whether it poses a threat.

Chemistry

Questions of Origin

Two new studies renew controversy about the authenticity of a map that may be the first depiction of North America.

Chemistry

Tums of the Sea

Ocean scientists question whether the seas can handle rising carbon dioxide concentrations.

Math

Logic in the Blocks

Sliding-block puzzles can be surprisingly difficult to solve and can even serve as theoretical models of computation.