In Japan, for centuries every school-child has learnt the art of folding paper : origami. In Europe, it is generally dunces and bored pupils who make paper fortune-tellers and aeroplanes at the back of the classroom…The rules are simple : no scissors, no glue, just a sheet of paper and folds. But origami is more than that. Origamists today are able to produce quite extraordinary and apparently impossible forms : whole cathedrals, insects with a full array of antennae and legs.Mathematicians, origamists and computer wizards have all played a part in the origami revolution over the past 20 years. They have mathematically demonstrated that they could fold everything, in any shape, no matter how complex.Today engineers, researchers in biology, robotics, nanotechnologies, are embracing this "origami philosophy". Engineers exploit the technique to deploy a solar sail in space, to fold a telescope or an airbag. In medicine, researchers develop folded microsensors to be injected into the human body and origami-inspired artificial skin. It also brings about a greater understanding of the world around us, in life sciences, in the comprehension of evolutive mechanisms concerning the selection of more ‘economical’ processes in the development of life. Scientists use origami concepts for computer simulations of protein and DNA ‘folding’ in their research into gene therapies.« The world in folds » explores the unexpected emergence of this playful, ancestral art on the frontiers of the most contemporary scientific research.