To keep communications secure in a post-quantum world, cryptographers are digging down into the concept of cause and effect.

Quantum space and time Physicists have developed no-go theorems that limit quantum processes in space–time causality. (Courtesy: iStock/piranka) Physicists have developed a new theoretical framework ...

Quantum mechanics wreaks even more havoc with conventional ideas of causality than some have suspected – according to a team of researchers based in Australia, with collaborators in Scotland and ...

A new theory could resolve longstanding tensions in mutually exclusive ideas about physics.

Alice and Bob, the stars of so many thought experiments, are cooking dinner when mishaps ensue. Alice accidentally drops a plate; the sound startles Bob, who burns himself on the stove and cries out.

BREAKFAST in my house is a causal affair. The kettle boils because I have switched it on. The toast acquires its golden crust because I put it in the toaster. The butter makes its way to the table ...