Nature Milestones: Photons is published this month by Nature Physics, Nature Materials and Nature Photonics. In a series of 'Milestone' articles and a collection of relevant research papers from the Nature Publishing Group archive, the supplement recounts the history of research with photons: from the controversy over the wave or particle nature of light and the setting down of Maxwell's equations, through holography and optical fibres to quantum information and metamaterials, to name but a few steps along the way. Of course, the invention of the laser, fifty years ago, is also a significant part of the story.

Credit: © ISTOCKPHOTO/DWPHOTOS

This is the tenth in the series of Milestones supplements, preceded by others on such topics as spin, light microscopy, DNA technologies and cancer. Following the advice of experts in the field, each Milestone article, written by an editor from a Nature journal, describes a breakthrough (or series of related breakthroughs) in the context of their time. The aim is to celebrate, in an engaging and concise style, the discoveries and their conceptual beauty, to note earlier achievements and subsequent impact. A comprehensive overview is not intended. After all, the twenty-odd articles cover so many, diverse topics — united as they are by their common theme of 'photons' — that whole books could be (and have been) written on each of them.

We hope you enjoy Nature Milestones: Photons. The Milestone articles are available free online at www.nature.com/milestones/milephotons (the research collection is free throughout May 2010). Personal subscribers to Nature Physics receive a free copy with the May issue of the journal.